1 of 71
TI: Drastic changes in deep-sea sediment porewater composition induced by episodic input of organic matter
AF: Earth and Planetary Sciences, McGill University, 3450 University Street, Montreal, Quebec, H3A 2A7 Canada
SO: Limnol.-Oceanogr. 1997 vol. 42, no. 5, pp. 980-986
LA: English
AB: We report the first seasonal time-series observations of porewater composition obtained for deep-sea sediments. We observed considerable temporal variability of O sub(2), NO sub(3) super(-), and Mn super(2+) profiles at the French JGOFS site DYFAMED (western Mediterranean) in response to a pulsed input of organic matter. A delivery of reactive organic matter representing only 1% of the average organic C content of surface sediments (0.6% wt/wt) was required in order to fuel the observed changes in porewater composition. The perturbation resulted in dramatic changes in integrated reaction rates and sediment-water fluxes. O sub(2) uptake rates increased from 1.26 to 1.82 mmol m super(-2) d super(-1), while nitrification rates rose from 0.13 to 0.18 mmol m super(-2) d super(-1). These changes were paralleled by a decrease in NO sub(3) super(-) effluxes across the sediment-water interface from 0.07 to 0.01 mmol m super(-2) d super(-1) and a concomitant rise of denitrification rates from 0.06 to 0.17 mmol m super(-2) d super(-1). Porewater profiles responded rapidly to the sediment pulse deposition, returning to their steady-state values within a few months. The main driving force appeared not to be the seasonal variability of pelagic production but rather the downslope transport of resuspended upper-shelf sediments.
AN: 4258721
2 of 71
TI: Chlorophyll-a and pheopigments as tracers of labile organic carbon at the Central Equatorial Pacific seafloor
AU: Stephens,-M.P.; Kadko,-D.C.; Smith,-C.R.; Latasa,-M.
AF: Div. Mar. and Atmos. Chem., Rosenstiel Sch. Mar. and Atmos. Sci., Univ. Miami, Miami, FL 33149, USA
SO: GEOCHIM.-COSMOCHIM.-ACTA 1997 vol. 61, no. 21, pp. 4605-4619
LA: English
ER: M (Marine)
AB: High rates of primary production and fast sinking rates lead to the deposition of phytodetritus and highly reactive organic matter to the sediments of the central Equatorial Pacific. These substances are responsible for driving important chemical fluxes and fueling benthic organisms. Chloropigments have proven useful as tracers of similar highly reactive organic carbon components in lacustrine and nearshore marine sediments. In this study we investigate the degradation of chlorophyll-a and pheopigments-a at four abyssal sites on the JGOFS equatorial Pacific transect along 140 degree W and explore the usefulness of these chloropigments as tracers of the most-reactive component of the deep-sea particulate organic carbon (POC) rain. First-order reaction rate constants (k = 1-75/yr, half-life 3-250 d) and relative reactivities (chlorophyll-a > allomer and pheophorbide-a > pheophytin-a) derived from most of the sedimentary profiles are similar to those found in laboratory and other field (lake and coastal marine) studies. However, in some profiles, the rate constants determined by fitting data below 0.5 cm are slower by up to 3 orders of magnitude despite an apparent abundance of bacteria, macrofauna, and porewater oxygen. Model results assuming multi-G kinetics suggest that these chloropigments degrade as two components: one, which accounts for at least 99% of the degradation and 11-57% of the sediment inventory, degrades with a half-life of 4-120 days. The other component degrades with a half-life of up to 440 years. These results suggest that some otherwise labile POC may be protected and escape rapid degradation near the sediment-water interface. If phytodetritus is deposited continuously throughout the year, our model-calculated chlorophyll-a fluxes indicate that it could account for 25-100% of the annual POC flux at sites close to the equator.
AN: 4283422
3 of 71
TI: Variation of CO sub(2) partial pressure in surface seawater in the equatorial Pacific Ocean
AU: Goyet,-C.; Peltzer,-E.T.
AF: Woods Hole Oceanographic Inst., 360 Woods Hole Rd., MS 25, Woods Hole, MA 02543, USA
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1997 vol. 44, no. 9-10, pp. 1611-1625
LA: English
ER: M (Marine)
AB: The partial pressure of CO sub(2) gas in surface seawater (pCO sub(2)usea) and in the atmosphere (pCO sub(2)uair) was continually measured in the equatorial Pacific Ocean during two US JGOFS cruises in 1992. Time-series measurements at the equator and 140 degree W show that the pCO sub(2) of surface seawater varied by 30 mu atm during the 2 week period of the experiment with a diurnal variation of close to 8 mu atm. The diurnal variations of pCO sub(2)usea were associated with the diurnal variations in sea surface water temperature, but the larger variation of pCO sub(2)usea on a weekly time-scale was associated with water movements (equatorial upwelling and passage of a tropical instability wave) rather than heating or cooling of surface seawater. The water movements are characterized by change in temperature as well as salinity, total inorganic carbon and total alkalinity. During the upwelling period, pCO sub(2)usea increased whereas sea surface temperature decreased. From the equator to 13 degree S, pCO sub(2)usea decreased from 430 mu atm to 340 mu atm whereas the sea surface temperature increased from 25.4 degree C to 28.3 degree C. However, there was no overall correlation between pCO sub(2)usea and sea surface temperature. Indeed, the pCO sub(2)usea varied irregularly with temperature across a complex system of fronts and eddies. The observed diurnal variations of pCO sub(2)usea while the ship was in transit between Tahiti and the equator were up to 8 mu atm.
AN: 4254023
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TI: Preliminary sedimentological and biological assessment of EUMELI project sites
OT: Caracterisation sedimentologique et biologique preliminaire des sites du projet EUMELI
AU: Auffret,-G.A.; Geistdoerfer,-P.; Gaillard,-J.F.; Reyss,-J.L.; Rabouille,-C.; Voisset,-M.; Coutelle,-A.; Muller,-C.; Kerbrat,-R.; Monti,-S.; Ondreas,-H.; Mauviel,-A.
AF: IFREMER Centre Brest, DRO GM, BP 70, 29280 Plouzane, France
SO: C.-R.-Acad.-Sci.-Ser.-2-Mec.-Phys.-Chim.-Sci.-Terre-Univers 1992 vol. 314, no. 2, pp. 187-194
LA: French
ER: M (Marine)
AB: The objective of the EUMELI project (JGOFS-FRANCE) is the study of particulate matter fluxes in three sites off the western African margin, submitted to a decreasing gradient of the primary production, from the Mauritanian margin under an active upwelling regime to an oceanic oligotrophic site. In each site a survey including: swath bathymetry, side scan sonar, sea floor imagery and sampling, has allowed one to locate a station where the interface is in equilibrium with inputs from surface waters.
AN: 4236645
5 of 71
TI: Joint Global Ocean Flux Study (JGOFS)
AU: Ittekot,-V.; Haake,-B.
AF: Institut fuer Biogeochemie und Meereschemie, Bundesstrasse 55, D-20146 Hamburg, FRG
CO: 5. Internationales Wissenschaftliches Symposium. Aktuelle Probleme der Meeresumwelt, Hamburg (FRG), 23-24 May 1995
SO: Actual-problems-of-the-marine-environment.-Lectures-at-the-5th-International-Scientific-Symposium.-AKTUELLE-PROBLEME-DER-MEERESUMWELT.-VORTRAEGE-DES-5.-INTERNATIONALEN-WISSENSCHAFTLICHEN-SYMPOSIUMS. 1995 no. 5 no. 5, 163
ST: Dtsch.-Hydrogr.-Z.-Suppl. no. 5
NT: Summary only.
ER: M (Marine)
AB: The IGBP program (International Geosphere-Biosphere Program) combines a number of research projects dealing with interactions between the physical, chemical, and biological processes which determine the earth's equilibrium and create the conditions on which life on earth depends. It is the goal of all IGBP projects to investigate the variability of the natural system and man's impact on it. The Joint Global Ocean Flux Study (JGOFS), one of the core projects of IGBP, aims at describing the cycles of carbon and associated biogenic elements in the ocean with a view to developing methods for predicting the effects of climate changes on biogeochemical processes in the ocean. This is of particular importance because the oceans contain 50 times more carbon than the atmosphere. The JGOFS project comprises (i) large-scale measurements of essential parameters, (ii) regional studies in selected parts of the ocean, and (iii) detailed process studies. Up to now, regional and process studies have been carried out in the Atlantic, Pacific, and in the southern ocean. The Arabian Sea, a tropic to subtropic, highly climate dependent ocean, has been chosen for a JGOFS process study in which numerous nations participate. Germany contributes a project, due to begin this year, which consists of 15 part projects and is supported by the Federal Ministry of Research and Technology. The German JGOFS contribution is coordinated by Institut fur Biogeochemie und Meereschemie in Hamburg. The institute has carried out JGOFS relevant studies in the Arabian Sea since 1986.
AN: 4212823
6 of 71
TI: Nitrification rates, ammonium and nitrate distribution in upper layers of the water column and in sediments of the Indian sector of the Southern Ocean
AU: Bianchi,-M.; Feliatra,-F.; Treguer,-P.; Vincendeau,-M.-A.; Morvan,-J.
AF: Microbiologie Mar., CNRS INSU UPR 223, Campus de Luminy, Case 907, F-13288 Marseille Cedex 9, France
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 5, pp. 1017-1032
NT: Special issue: ANTARES 1: France JGOFS.
LA: English
ER: M (Marine)
AB: During the ANTARES 1/F-JGOFS cruise (April-May 1993) concentrations of inorganic nitrogen, nitrification rates (ammonium and nitrite oxidation) and super(14)C carbonate incorporation by nitrifying bacteria were measured at 0, 50 and 100 m in the water column, and at the water-sediment interface between the polar front (52 degree S) and the subantarctic and subtropical fronts (42 degree S) in the Indian Ocean Sector of the Antarctic Ocean. The 0-100 m water layer showed a global increase of NH sub(4) super(+) (from 0.4 to 0.6 mu M) and a global decrease of NO sub(2) super( )+ NO sub(3) super(-) (from 25 to 5 mu M) along the south-north transect. Anomalies were detected for both ammonium and nitrite + nitrate concentrations in the SubTropical Front (STF) and SubAntarctic Front (SAF). Pelagic nitrifying activities (N oxidation) did not demonstrate any latitudinal gradient in the water column. In terms of integrated rates between 0 and 100 m, the nitrification increased by a factor 1.8-2 in the STF-SAF area. The N oxidation processes mostly depended on the substrate availability. For both ammonium and nitrite oxidizers the C fixation was well correlated (r = 0.68, p = 0.001 and r = 0.98, p = 0.0001, respectively) with N oxidation, in the range of 15 N (ammonium oxidizers) and 20 N (nitrite oxidizers) oxidized for 1 C incorporated. For nitrite oxidizers, C incorporation was principally influenced by temperature (Q sub(10) = 1,73). From the calculation of nitrogen fluxes, the nitrifiers would be able to compete with the primary producers for the regenerated ammonium, while the flux of nitrate produced by nitrification could sustain 10 to 100% of the primary producer requirements for this nitrogen source. In the sediment pore waters, the inorganic nitrogen compounds displayed two different latitudinal distributions. The ammonium concentrations were lower (around 4 mu M) south of the 48 degree S than in the northern part (values reaching 10 mu M in the first centimetre). The nitrite + nitrate concentrations were close to 40-45 mu M at each end of the transect, and increased to 50-55 mu M near 45 degree S. The benthic nitrification, measured from 0 to 5 cm depth in the sediment cores, showed high rates in the upper 3 cm. The rates of ammonium oxidation demonstrated a good correlation (r = 0.64, p = 0.0001) with the ammonium content of the interstitial water. The nitrite oxidation rates were well correlated (r = 0.92, p = 0.0001) with the ammonium oxidation rates. The integrated rates (0-5 cm) of ammonium oxidation were of about 35 nmol NO sub(2) super(-) produced/cm super(2)/day in the south, and increased by a factor 1.3-1.9 after 44 degree S. Both ammonium and nitrite oxidation rates showed a maximum near 44 degree S, corresponding to the SAF-STF frontal zone.
AN: 4221047
7 of 71
TI: Bacterial proteolytic activity in sediments of the Subantarctic Indian Ocean sector
AU: Talbot,-V.; Bianchi,-M.
AF: Lab. de Microbiologie Mar., CNRS UPR 223, Campus de Luminy, Case 907, F-13288 Marseille Cedex 9, France
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 5, pp. 1069-1084
NT: Special issue: ANTARES 1: France JGOFS.
LA: English
ER: M (Marine)
AB: Organic material entering the oceanic benthic zone can be permanently buried or recycled to CO sub(2) in the sediment. Therefore it is important to know the carbon flux across the sediment-water interface to determine the initial and rate-limiting step in carbon oxidation, a bacterial enzymatic activity. Bacterial density and ectoproteolytic activity, determined using a fluorogenic substrate analog (L-leucine-7-amino-4-methyl coumarin, Leu-MCA) were investigated in the water column and in sediments during the ANTARES 1 JGOFS cruise in the Indian sector of the Southern Ocean. A strong decrease in ectoproteolytic activity was observed with increasing water depth. Peak activity in surface water was three orders of magnitude less than in surface sediment. Analysis of experimental data revealed, for most sediment bacterial communities, the existence of a biphasic mechanism with different velocities for organic matter degradation and different affinities of enzymatic systems for substrates. To explain this, we hypothesize a strategy of bacterial communities that use the episodic supplies of organic matter reaching the sediment. Microbial ectoproteolytic activities were highest in surface sediment horizons and decreased progressively with depth. As benthic microbial activities reflect the quantity and quality of organic matter reaching the sea floor, high potential ectoproteolytic activities (PEA) measured in the sediment of the Polar Front Zone could indicate a direct and rapid coupling of relatively high surface productivity and deep ocean water by sinking particle fluxes. Lower values of PEA were found in sediment in the northern study area where lateral processes associated with ocean circulation (Antarctic Circumpolar Current) have an important influence on settling particles. The lowest sediment PEA values were measured at 52 degree S, a region in which low primary production provides a poor supply of organic matter for the sea floor.
AN: 4221045
8 of 71
TI: Aluminium and silicic acid in water and sediments of the Enderby and Crozet basins
AU: Van-Beusekom,-J.E.E.; Van-Bennekom,-A.J.; Treguer,-P.; Morvan,-J.
AF: Biologische Anstalt Helgoland, Notkestrasse 31, D-22607 Hamburg, Germany
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 5, pp. 987-1003
NT: Special issue: ANTARES 1: France JGOFS.
LA: English
ER: M (Marine)
AB: The distributions of dissolved aluminium (Al) and silicic acid (H sub(4)SiO sub(4)) were investigated in the Indian sector of the Southern Ocean along a hydrographic section from 52 degree S in the eastern Enderby Basin to 39 degree S in the western Crozet Basin. Going northward, there is a clear increase of Al concentrations at all depths, starting with a nearly featureless profile (Al generally below 1 nM) at the southernmost station, to profiles with maxima of 4.09 nM at 500 m and 3.57 nM in bottom waters at the northern stations. The general trend is interrupted by intrusions of Antarctic Intermediate Water with low Al, coinciding with oxygen maxima > 260 mu M. In the surface layer, H sub(4)SiO sub(4) ranged from 1.5 to 5 mu M and increased continuously with depth to 158.7 mu M in the southernmost bottom water and to 141 mu M in the bottom water of the Crozet Basin. There is a linear relation between H sub(4)SiO sub(4) and salinity, except in the eastern Enderby Basin, where the bottom water is enriched in H sub(4)SiO sub(4). At the eastern flank of the Crozet Plateau, a western boundary current was observed carrying deep water with about 2.3 nM Al and 155-156 mu M H sub(4)SiO sub(4). This indicates a net input of H sub(4)SiO sub(4) and no net input of Al during water transport from the western Weddell Basin to the Crozet-Kerguelen Passage. At the southernmost station all Al concentrations, ranging from 0.84 to 1.2 nM, with minima of 0.3-0.5 nM between 500 and 1000 m, are below the values reported for the western Weddell Sea, where the water originates. Also the Al values in the salinity maximum of the Circumpolar Deep Water are lower than expected from the intrusion of saline, Al-rich North Atlantic Deep Water. Both observations suggest that scavenging of Al, possibly by diatoms, occurs in parts of the Southern Ocean. In the Crozet Basin deep waters, H sub(4)SiO sub(4) behaves conservatively, while increased concentrations of dissolved Al in bottom waters are due to input from the sediments. In the eastern Enderby Basin, excess H sub(4)SiO sub(4) in bottom waters indicates input from the sediment, without such an input of Al. This is explained by the higher concentrations of H sub(4)SiO sub(4) and lower dissolved Al in pore waters of the Enderby Basin, compared to the Crozet Basin. The Al/Si ratios of biogenic silica in the sediment were 0.0027 in the Enderby Basin and 0.011 in the Crozet Basin, both higher than in diatoms from surface waters. It is suggested that the biogenic silica-rich surface sediment in the Enderby Basin acts as a filter for Al, diffusing upward from pore water, whereas the low Al/Si ratios in biogenic silica support a marked H sub(4)SiO sub(4) flux into the bottom waters. In the Crozet Basin sediments, with less biogenic silica and more Al-releasing terrigenous material, some dissolved Al can escape into bottom water, but the higher Al/Si ratios in biogenic silica suppress release of H sub(4)SiO sub(4).
AN: 4206607
9 of 71
TI: Cross-frontal exchange of Antarctic Intermediate Water and Antarctic Bottom Water in the Crozet Basin
AU: Park,-Y.-H.; Gamberoni,-L.
AF: Lab. d'Oceanographie Physique, Mus. Natl. d'Histoire Naturelle, 43 Rue Cuvier, 75005 Paris, France
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 5, pp. 963-986
NT: Special issue: ANTARES 1: France JGOFS.
LA: English
ER: M (Marine)
AB: The hydrographic survey made across the Antarctic Circumpolar Current (ACC) in the southwestern Crozet Basin during the April-May 1993 ANTARES-1 cruise revealed unprecedented strong cross-frontal injections of newly formed Antarctic Intermediate Water (AAIW) into the subtropical zone north of the ACC. The ACC in this area is mostly associated with the Subantarctic Front (SAF) and Subtropical Front (STF), which are tightly merged into one structure bordered to the north with the eastward extension of the Agulhas Return Current. The oxygen and salinity extrema of the newly injected AAIW, at a depth of 1200 m, well north of the STF, reach as high as 6.17 ml/l and 34.15. These values coincide almost exactly with those in the AAIW source, found at a depth of 500 m, just south of the SAF, but surpass considerably (oxygen by + 1.35 ml/l and salinity by -0.23 psu) those values corresponding to the old AAIW at the nearby subtropical stations. Such spectacular cross-frontal injections of new AAIW were not continuous in space and time, but were found to be rather local, intermittent and impulsive. This was closely correlated with the highly perturbed, meandering frontal zone due to the frequent passages of strong atmospheric depressions during the cruise. There is also clear evidence of the northward penetration of Antarctic Bottom Water (AABW) through the Crozet-Kerguelen gap and its northward flow along the deep western boundary of the Crozet Basin, supporting previous observations. Moreover, our observations indicate more precisely the bottom water pathway, which is concentrated against the continental rise west of 56 degree E, following roughly the 4000 m isobath. It is concluded that the Crozet Basin frontal zone acts as a barrier only for the upper layer water masses, and that it is dynamically transparent for the cross-frontal exchange of intermediate and deeper layer water masses of potential density anomalies greater than sigma sub( theta ) = 27.1, including AAIW and AABW.
AN: 4206606
10 of 71
TI: ANTARES-I: A biogeochemical study of the Indian sector of the Southern Ocean
AU: Gaillard,-J.-F.
AF: Dep. Civ. Eng., Northwestern Univ., 2145 Sheridan Rd., Evanston, IL 60208-3109, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 5, pp. 951-961
NT: Special issue: ANTARES 1: France JGOFS.
LA: English
ER: M (Marine)
AB: The first expedition of the ANTARES program, the French contribution to Southern-JGOFS, investigated the biology and the chemistry of the benthic environment and the water column in a region located between 60 degree S-72 degree E and 39 degree S-55 degree E. In this special issue, we present a detailed description of the transports of water masses across the polar front zone, which are corroborated by chemical and microbial tracer studies, a description of the sediment-water interface bridging biological, chemical, and microbial studies, and new insights into the diagenesis of biogenic silica.
AN: 4206605
11 of 71
TI: What are upwelling systems contributing to the ocean's carbon and nutrient budgets?
AU: Toggweiler,-J.R.; Carson,-S.
AF: GFDL/NOAA, Princeton Univ., P.O. Box 308, Princeton, NJ 08542, USA
CO: Dahlem Workshop on Upwelling in the Ocean: Modern Processes and Ancient Records, Berlin (Germany), 25-30 Sep 1994
SO: UPWELLING-IN-THE-OCEAN:-MODERN-PROCESSES-AND-ANCIENT-RECORDS. Summerhayes,-C.P.;Emeis,-K.-C.;Angel,-M.V.;Smith,-R.L.;Zeitzschel,-B.-eds. JOHN-WILEY-and-SONS no. 18 pp. 337-360
ST: ENVIRON.-SCI.-RES.-REP. 1995 no. 18
LA: English
ER: M (Marine)
AB: Understanding the effect of upwelling systems on the carbon cycle requires detailed knowledge of how nutrients and carbon enter and leave these systems. In this article we use recent findings of the JGOFS equatorial Pacific process study and a detailed three-dimensional model to look specifically at the nitrate budget in the equatorial Pacific. Nitrate enters the equatorial upwelling system in the far-western Pacific via the Equatorial Undercurrent. Because the equatorial biota tend to recycle nitrogen much more effectively than they export nitrogen in sinking particles, nitrate stocks build up in the eastern Pacific. A significant fraction of the nitrate entering the upwelling system seems to be lost to denitrification in the anoxic zones off Peru and Central America. Through denitrification, the equatorial upwelling system may function as a regulator of global nitrate stocks and air-sea partitioning of CO sub(2). (DBO)
AN: 4205465
12 of 71
TI: Biogenic silica recycling in surficial sediments across the polar front of the Southern Ocean (Indian Sector)
AU: Rabouille,-C.; Gaillard,-J.-F.; Treguer,-P.; Vincendeau,-M.-A.
AF: Cent. des Faibles Radioactivites, Lab. Mixte CNRS-CEA, Av. de la Terrasse, 91190 Gif sur Yvette, France
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 5, pp. 1151-1176
NT: Special issue: ANTARES 1: France JGOFS.
LA: English
ER: M (Marine)
AB: The processes controlling preservation and recycling of particulate biogenic silica in superficial sediments must be understood before one uses biogenic silica as a proxy in paleo-oceanographic studies, and in order to compute oceanic mass balances for silica. In this respect, the Antarctic Ocean is certainly a key region due to its high productivity and export of biogenic silica. In order to quantify sedimentary fluxes and identify crucial processes that allow the preservation of biogenic silica, pore water and solid phase silica profiles were performed on sediment cores from the Southern Ocean (Indian Sector) during the ANTARES 1 cruise. In combination with solubility data reported by Van Cappellen and Qiu (1997a), a process model representing the early diagenesis of silica was developed. In this model, a dependence with depth of the kinetic constant was introduced to allow the preservation of biogenic silica in sediment porewater undersaturated with respect to that phase. Using this steady-state model, it is proposed that a proportionality of the reactivity of the biogenic silica with its settling flux is necessary to explain the observed profiles. It is then shown using this model that the preservation of biogenic silica is not a linear function of the deposited flux. Using a modified version of this model containing an explicit term of reprecipitation, we hypothesize that reprecipitation alone cannot counterbalance dissolution and that its effect is certainly related to a decrease in either surface solubility or kinetics of dissolution.
AN: 4201296
13 of 71
TI: Biogenic silica dissolution in sediments of the Southern Ocean. 2. Kinetics
AU: Van-Cappellen,-P.; Qui,-L.
AF: Sch. Earth and Atmos. Sci., Georgia Inst. Technol., Atlanta, GA 30332-0340, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 5, pp. 1129-1149
NT: Special issue: ANTARES 1: France JGOFS.
LA: English
ER: M (Marine)
AB: The dissolution kinetics of biogenic silica in surface sediments collected during the ANTARES I cruise were measured in stirred flow-through reactors. The rate data exhibit a distinctly non-linear dependence on the degree of undersaturation. Near equilibrium, the rates of silica dissolution and precipitation define a single linear trend, i.e. the kinetics are symmetric about the equilibrium point. When the dissolved silica concentration drops below a critical level, however, the dissolution rate rises exponentially with increasing undersaturation. Hence, the data disagree with the linear rate law generally used to describe the dissolution kinetics of biogenic silica. It is hypothesized that the kinetic transition from the linear to the exponential regime represents the onset of localized dissolution centered on surface defects, e.g. small pores and crevices, or compositional defects. The effects of temperature and pH confirm that the critical process controlling the overall dissolution kinetics is the hydrolysis of bridging Si-O-Si bonds at the solid-solution interface. The rate measurements indicate that the reactivity of biogenic silica decreases substantially with depth in the sediment. The decrease in reactivity is explained by a progressive reduction of the defect density of the silica surfaces, through dissolution and reprecipitation of silica. It does not appear to result from the preferential dissolution of a more reactive fraction of biogenic debris deposited from the water column. Surface areas obtained by the N sub(2)-BET method or concentrations of extractable biogenic silica do not provide satisfactory proxies for the reactive surface area of silica in the sediments. However, a positive correlation was observed between the surface reactivity and the exchangeable Co super(2+) adsorption capacity of biogenic silica. Specific kinetic effects on silica dissolution of the aluminum content of the silica surfaces or organic matter coatings were not observed. Both the non-linear dissolution kinetics and the aging of the silica surfaces help restrict the dissolution of deposited biogenic silica to a narrow zone close to the water-sediment interface. The results of the flow-through experiments highlight the importance of in situ early diagenetic processes in controlling the behavior and fate of deposited biogenic silica: no evidence was found supporting a significant effect of differences in solubility or reactivity inherited from the biomineralization process in the water column.
AN: 4201295
14 of 71
TI: Organic geochemistry of marine sediments of the subantarctic Indian Ocean sector: lipid classes - sources and fate
AU: Laureillard,-J.; Pinturier,-L.; Fillaux,-J.; Saliot,-A.
AF: Lab. de Physique et Chimie Marines, Unite de Recherche Associee au CNRS No. 2076, Univ. Pierre et Marie Curie, Case 134, Tour 25-24, 4 Place Jussieu, F-75252 Paris Cedex 05, France
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 5, pp. 1085-1108
NT: Special issue: Antares 1: France JGOFS.
LA: English
ER: M (Marine)
AB: Nine sections of core KTB16 (47 degree 59'98 S, 55 degree 59'74 E, 4240 m) taken from the Indian Ocean sector of the Antarctic Polar Front Zone were analyzed for their lipid class and total chlorin contents using thin-layer chromatography-flame ionisation detection (TLC/FID). The following series were included: hydrocarbons, chlorins and chlorin esters, alcohols, sterols, triacylglycerols, free fatty acids and phospholipids. For these major classes, the distribution of their individual components was determined to evaluate the source and fate of each lipid class. Relationships between the lipid composition of overlying particles and of buried material were investigated. The sediment-water interface was found to be of primary importance in the biogeochemical transformations occurring in organic matter, such as loss of the major part of the lipids, and formation of a notable unresolved complex mixture (UCM), of biological origin. Some classes such as chlorin esters appeared to convey their lipid contents from the upper layers without major alteration. In contrast, several other classes, such as storage lipids, appeared to be degraded during sedimentation, indicating extensive recycling of labile lipids in the water column. The burial efficiency and bacterial inputs downcore were highly variable depending on the class considered. Several novel compounds are reported. They consist of alkyl chlorin esters and include a wide variety of saturated and unsaturated long-chain alcohols. Owing to the lack of lipid data in the study area, these results provide an insight into the various biological and chemical processes occurring in open-sea Antarctic sedimentary environments.
AN: 4114533
15 of 71
TI: Biogenic silica dissolution in sediments of the Southern Ocean. 1. Solubility
AU: Van-Cappellen,-P.; Qiu,-L.
AF: Sch. Earth and Atmos. Sci., Georgia Inst. Technol., Atlanta, GA 30332-0340, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 5, pp. 1109-1128
NT: Special issue: Antares 1: France JGOFS.
LA: English
ER: M (Marine)
AB: A stirred flow-through reactor technique was used to determine silica solubilities in sediments collected with a multicorer in the Indian sector of the Southern Ocean (ANTARES I cruise). The results show that the apparent silica solubility in the cores may decrease, increase or remain constant with depth. The silica solubility profiles are best explained by the early diagenetic interactions between biogenic silica and soluble aluminum derived from detrital material. By combining the solubility data with measured dissolved silica profiles, it is shown that the variable asymptotic pore water silica levels in the cores cannot be explained solely by differences in silica solubility. In sediments that experience a significant detrital input, the simultaneous reprecipitation of dissolved aluminum and dissolved silica prevents pore water silicic acid from reaching saturation with the dissolving biogenic silica. The principal oceanographic control on pore water silica build-up in the cores studied is the ratio of the deposition fluxes of biogenic silica and detrital material. Solubility differences inherited from the biomineralization process in the surface waters do not appear to have a significant effect on the observed pore water silica levels.
AN: 4114532
16 of 71
TI: Estimation of total CO sub(2) concentration throughout the water column
AU: Goyet,-C.; Davis,-D.
AF: Woods Hole Oceanographic Inst., 360 Woods Hole Rd. MS 25, Woods Hole, MA 02543, USA
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1997 vol. 44, no. 5, pp. 859-877
LA: English
ER: M (Marine)
AB: We use total CO sub(2) data sets measured on the recent Joint Global Ocean Flux Study (JGOFS) and World Ocean Circulation Experiment (WOCE) cruises to investigate potential parameterizations of TCO sub(2) data sets. The observed temporal variations of TCO sub(2) in surface seawater were large (4% of the signal within a month) compared to the relatively small spatial variations (<2% over 10 degree latitude). Yet the result of our study suggests that a single sigmoid function can be used to fit, parameterize, and interpolate closely (within the accuracy of the measurement) each upper ocean (<250 m) TCO sub(2)-depth profile of the temporal and spatial data sets from the North Atlantic and Equatorial Pacific Oceans that we examined. This sigmoid function is not specific to TCO sub(2) data sets, and it could probably be used over most (if not all) of the upper ocean to fit, parameterize, and interpolate physical and chemical oceanic data sets. Below the upper layer (depth > 250 m) TCO sub(2) can be parameterized by the relationship TCO sub(2) = a + b Theta + c AOU + dS where Theta , AOU, and S represents potential temperature, apparent oxygen utilization and salinity, respectively. The coefficients a, b, c, and d are experimentally determined by multiple linear regression using discrete bottle data from depths below the wintertime mixed layer depth. Densely sampled CTD data of temperature, salinity, and oxygen can then be used to interpolate TCO sub(2) data at non-sampled depths. The two parameterized functions describing TCO sub(2) in and below the upper ocean can further be blended at the wintertime mixed layer depth to yield a continuous estimate of TCO sub(2) concentration throughout the water column.
AN: 4113056
17 of 71
TI: Antarctic marine ecosystems research in post-biomass years
AU: El-Sayad,-S.
AF: Department of Oceanography, Texas A and M University, College Station, TX 77843-3146, USA
CA: IOC, Paris [France]
CO: 6. Sess. IOC Regional Committee for the Southern Ocean, Bremerhaven (Germany), 9-13 Sep 1996
SO: PRINC.-ORGANES-SUBSID.-COI PARIS-FRANCE UNESCO 1996 no. 71 no. 71
ST: REP.-GOV.-MAJOR-SUBSID.-BODIES-IOC-INF.-ORGANOS-RECTORES-ORGANOS-SUBSID.-PRINC.-COI-RAPP.-ORGANES-DIR.-PRINC.-ORGANES-SUBSID.-COI no. 71
NT: 1. Southern Ocean Forum, Bremerhaven (Germany) 9-11 Sep 1996Summary only.
RN: IOC/SOC-VI/3; SC-96/WS/48 (SC96WS48)
LA: English
ER: M (Marine)
AB: With the growing concern over the conservation of the Southern Ocean ecosystems and their living resources and with the worldwide awareness over climate change as a result of increased levels of carbon dioxide, and the depletion of stratospheric ozone over Antarctica, Antarctica became the focal point of global conservation in the 1980's. As a result we have witnessed the initiation of several scientific programmes to address these concerns. Foremost among these programmes (in the early 1980's) was the BIOMASS Programme. Within its relatively short life span, BIOMASS provided several important insights into the functioning of the Southern Ocean ecosystems, and has rekindled great international interest in Antarctic affairs reminiscent of the International Geophysical Year. In so doing, it helped in creating a climate which research programmes addressing elements of the general and specific objectives of BIOMASS were able to flourish. This has led to an explosion of marine research programmes to study phenomena and processes of global significance in which Antarctica and the surrounding seas play a key role. A few of the programmes that have a focus on the Antarctic marine ecosystems and their living resources, e.g. CCAMLR Ecosystem Monitoring Programme, Southern Ocean-Joint Global Ocean Flux Study (SO-JGOFS), Southern Ocean Global Ocean Ecosystem Dynamics (SO-GLOBEC), Coastal and Shelf Ecology of the Antarctic Sea-Ice Zone (CS-EASIZ), are discussed and their contributions to a better understanding of the Antarctic marine ecosystems evaluated.
AN: 4103599
18 of 71
TI: A synoptic atmospheric surface forcing data set and physical upper ocean model for the U.S. JGOFS Bermuda Atlantic Time-Series Study site
AU: Doney,-S.C.
AF: Climate and Global Dynamics Div., Natl. Cent. for Atmos. Res., Boulder, CO, USA
SO: J.-GEOPHYS.-RES.-C-OCEANS 1996 vol. 101, no. C11, pp. 25,615-25,634
LA: English
ER: M (Marine)
AB: An atmospheric surface forcing data set with synoptic temporal resolution is constructed for the U.S. Joint Global Ocean Flux Study (JGOFS) Bermuda Atlantic Time Series (BATS) site for 1988-1992. The forcing data set is based primarily on the 6-hourly European Centre for Medium Range Weather Forecasts (ECMWF) operational analysis, daily cloud fraction and surface insolation estimates from the International Satellite Cloud Climatology Project, and monthly derived satellite precipitation estimates from the microwave sounding unit. Good agreement is found between the ECMWF surface properties (e.g., wind speed, air temperature) and synoptic meteorological data from the Bermuda airport and Comprehensive Ocean-Atmosphere Data Set (COADS) ship reports, though the analysis tends to damp the amplitude of extreme weather events. Monthly air-sea heat and freshwater flux estimates are generally consistent with climatological estimates for the BATS region. The diagnosed net heat and freshwater fluxes from the BATS conductivity-temperature-depth data show significant additional month to month variability that is not related to local atmospheric forcing but appears to arise from mesoscale advection. The surface forcing data set is then coupled to a one-dimensional upper ocean boundary layer model, and the resulting simulations quantitatively reproduce much of the observed behavior of sea surface temperature, heat content, and mixed layer depth for the BATS site for the period October 1988 through September 1992. The induced variability in the ocean model on diurnal and storm timescales is analyzed, and the impact of using the ECMWF analysis data rather than synoptic ship or mooring observations is also examined. The main deficiencies in the simulation are related to the influence of advective events in the BATS record and to possible shifts in the ECMWF model, and preliminary techniques for addressing these problems by incorporating the horizontal advective effects are presented. The difficulties associated with directly verifying local one-dimensional models using coarsely sampled time-series data is also discussed.
AN: 4105944
19 of 71
TI: Seasonal variation of chlorophyll and primary productivity in central Arabian Sea: A macrocalibrated upper ocean ecosystem model
AU: Sharada,-M.K.; Yajnik,-K.S.
AF: CSIR Centre for Mathematical Modelling and Computer Simulation (C-MMACS), Bangalore 560 037, India
SO: PROC.-INDIAN-ACAD.-SCI.-EARTH-PLANET.-SCI. 1997 vol. 106, no. 1-2, pp. 33-42
LA: English
ER: M (Marine)
AB: Seasonal variation of chlorophyll has been of considerable interest on account of the effect of photosynthesis on ocean-atmosphere carbon exchange. It can be predicted by a dynamical system model of the marine ecosystem coupled with a physical oceanographic model. There is however a major difficulty in the calibration of contemporary ecosystem models on account of sparse data and a large number of model parameters. This paper reports a new approach of macrocalibration in which values of six parameters are determined by examining in detail the seasonal variation of chlorophyll and primary productivity keeping in view the observations of two Indian JGOFS cruises. Both switching and nonswitching versions of grazing functions are used in a 7-component FDM model. Detailed simulations are reported for one station (16 degree N, 65 degree E). They show the effects of dependence of grazing preference on prey density on the behaviour of the ecosystem. The results of the simulation also provide a partial basis for developing correlations of primary production with chlorophyll and sediment flux.
AN: 4103971
20 of 71
TI: Activities of Scientific Committee on Oceanic Research (SCOR of ICSU) related to the Southern Ocean Study
AU: Stromberg,-J.-O.
AF: Scientific Committee on Oceanic Research, Kristineberg Marine Research Station, S-45034 Fiskebaeckskil, Sweden
CA: IOC, Paris [France]
CO: 6. Sess. IOC Regional Committee for the Southern Ocean, Bremerhaven (Germany), 9-13 Sep 1996
SO: R.-PRINC.-ORGANES-SUBSID.-COI PARIS-FRANCE UNESCO 1996 no. 71 no. 71
ST: REP.-GOV.-MAJOR-SUBSID.-BODIES-IOC-INF.-ORGANOS-RECTORES-ORGANOS-SUBSID.-PRINC.-COI-RAPP.-ORGANES-DIR.-PRINC.-ORGANES-SUBSID.-COI no. 71
NT: 1. Southern Ocean Forum, Bremerhaven (Germany) 9-11 Sep 1996Summary only.
RN: IOC/SOC-VI/3; SC-96/WS/48 (SC96WS48)
LA: English
ER: M (Marine)
AB: A short account is given of the 3 organizations within ICSU that are of interest in relation to the Southern Ocean: 1) IGBP, which has 3 core projects (JGOFS, GLOBEC and LOICZ); 2) SCAR, which has groups of experts and standing committees; and 3) SCOR, which has short-term working groups and more long-lived Scientific Committees, e.g. GLOBEC. The latter (Global Ocean Ecosystem Dynamics), as a global project, is now co-sponsored by IGBP, SCOR and IOC. It has presently 4 major components: 1) Carrying Capacity and Climate Change in the North Pacific (cosponsored by PICES); 2) Cod and Climate Change of the North Atlantic (co-sponsored by ICES); 3) Small Pelagic fish and Climate Change; and, 4) Southern Ocean GLOBEC. An Implementation Plan for Southern Ocean GLOBEC has been published and outlines the 3 proposed study areas, time series surveys, process studies and modeling efforts needed. Data management, timing and implementation management are also outlined.
AN: 4103612
21 of 71
TI: Activities of the Intergovernmental Oceanographic Commission (IOC) in the Southern Ocean
AU: Tolkatchev,-A.
AF: IOC/UNESCO, 1, rue Miollis, 75015 Paris, France
CA: IOC, Paris [France]
CO: 6. Sess. IOC Regional Committee for the Southern Ocean, Bremerhaven (Germany), 9-13 Sep 1996
SO: R.-PRINC.-ORGANES-SUBSID.-COI PARIS-FRANCE UNESCO 1996 no. 71 no. 71
ST: REP.-GOV.-MAJOR-SUBSID.-BODIES-IOC-INF.-ORGANOS-RECTORES-ORGANOS-SUBSID.-PRINC.-COI-RAPP.-ORGANES-DIR.-PRINC.-ORGANES-SUBSID.-COI no. 71
NT: 1. Southern Ocean Forum, Bremerhaven (Germany) 9-11 Sep 1996Summary only.
RN: IOC/SOC-VI/3; SC-96/WS/48 (SC96WS48)
LA: English
ER: M (Marine)
AB: The Intergovermnental Oceanographic Commission (IOC) is a functionally autonomous body within UNESCO and now includes 125 Member States. The Commission serves the Members of the UN family in their implementation of joint programmes relating to ocean research and observation. The Commission implements programmes within three subject areas: marine sciences; ocean services; and training, education and mutual assistance/capacity building. Since 1987, the activities of the Commission in the Southern Ocean have been carried out mainly within the framework of other research programmes, in particular: 1) World Climate Research Programme, sponsored by WMO, IOC, ICSU, particularly WOCE Southern Ocean; 2) IOC-UNEP-IMO-IAEA Programme on Global Investigation of Pollution in the Marine Environment (GIPME); 3) Cooperation with SCOR in the IGBP Joint Global Ocean Flux Study (JGOFS), particularly JGOFS Southern Ocean Study; 4) Global Ocean Ecosystem Dynamics (GLOBEC) programme jointly sponsored by SCOR and IOC, particularly GLOBEC Southern Ocean component; 5) General Bathymetric Chart of the Oceans (GEBCO) jointly with IHO and regional bathymetric/geological /geophysical charts. On-going ocean services activities include: 1) Joint IOC-WMO Integrated Global Ocean Services System (IGOSS); 2) IOC Global Sea-Level Observing System (GLOSS) including Southern Ocean Sea-Level Project; 3) WMO-IOC Data Buoy Programme (DBCP), including South Atlantic Buoy Programme and, Antarctic Buoy Programme; 4) IOC International Oceanographic Data and Information Exchange (IODE) System, including activities of the Responsible National Oceanographic Center for the Southern Ocean (Argentina). Development of the Global Ocean Observing System (GOOS) in co-operation with WMO, UNEP and ICSU in response to the appeal of Second World Climate Conference (1990) and United Nations Conference on Environment and Development (1992). GOOS will also provide the oceanographic data needed by the Global Climate Observing System (GCOS) sponsored jointly by WMO, IOC, UNEP and ICSU.
AN: 4103604
22 of 71
TI: Spring development of phytoplankton biomass and composition in major water masses of the Atlantic sector of the Southern Ocean
AU: Bathmann,-U.V.; Scharek,-R.; Klaas,-C.; Dubischar,-C.D.; Smetacek,-V.
AF: Alfred-Wegener-Inst. for Polar and Mar. Res., 27515 Bremerhaven, Germany
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 1-2, pp. 51-67
LA: English
ER: M (Marine)
AB: The distribution and composition of phytoplankton stocks in relation to water masses were studied during the SO-JGOFS cruise of R.V. Polarstern in the Atlantic sector of the Southern Ocean in October/November 1992. The cruise comprised one west-to-east transect along the ice edge from 49 degree W to 6 degree W and several meridional transects along 6 degree W that extended from the closed pack ice of the Weddell Sea, across the southern Antarctic Circumpolar Current (ACC) and into the Polar Frontal Zone. Chlorophyll (chl a concentrations, temperature and salinity were recorded continuously in surface water during the transects. Vertical distribution and species composition of microplankton were assessed microscopically in discrete water samples collected at stations. Contrary to expectations, no significant enhancement of phytoplankton biomass was found in the vicinity of the retreating ice cover. Melt-water-influenced zones were indicated by low salinity but also by abundance of characteristic sea-ice species such as Nitzschia closterium and N. prolongatoides, but chlorophyll concentrations averaged only 0.3 mg chl a m super(-3) and barely increased during the spring. Values were even lower and remained constant in the southern ACC (ca 0.2 mg chl a m super(-3)). In contrast, large phytoplankton blooms developed during the 6 weeks of investigation in the region of the Polar Front (PFr), from 0.7 to >4 mg chl a m super(-3). Three distinct blooms extended below 70 m depth, each dominated by a different diatom species (Fragilariopsis kerguelensis, Corethron inerme and C. criophilum). We speculate that the large phytoplankton stocks below 40 m depth are a result of subduction of surface layers as sinking and in situ growth can be ruled out. The factors leading to the accumulation of high phytoplankton stocks in the PFr (up to 270 mg chl m super(-2)), but not in the meltwater zones or in the front between ACC and Weddell Gyre, are not clear, but higher iron concentrations in the former region seem to have played a role.
AN: 4092491
23 of 71
TI: Ecology and biogeochemistry of the Antarctic Circumpolar Current during austral spring: A summary of Southern Ocean JGOFS cruise ANT X/6 of R.V. Polarstern
AU: Smetacek,-V.; De-Baar,-H.J.W.; Bathmann,-U.V.; Lochte,-K.; Rutgers-Van-Der-Loeff,-M.M.
AF: Alfred Wegener Inst. for Polar and Mar. Res., D-27515 Bremerhaven, Germany
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 1-2, pp. 1-21
LA: English
ER: M (Marine)
AB: The R.V. Polarstern cruise ANT X/6, part of the international Southern Ocean JGOFS programme, investigated plankton spring bloom development and its biogeochemical effects in different water masses of the Atlantic sector of the Southern Ocean: the Polar Frontal region (PFr), the southern Antarctic Circumpolar Current zone (sACC), its boundary with the Weddell Gyre (AWB) and the marginal ice zone (MIZ). The relative roles of physical stability, iron limitation and grazing pressure in enhancing or constraining phytoplankton biomass accumulation were examined. Three sections were carried out between the PFr and the ice edge along the 6 degree W meridian from early October to late November 1992. This paper summarises the major findings of the cruise and discusses their implications for our understanding of Southern Ocean ecology and biogeochemistry. A major finding was the negligible build-up of plankton biomass and concomitant absence of CO sub(2) drawdown associated with seasonal retreat of the ice cover. In striking contrast to this unexpected poverty of both the MIZ and the frontal region of the AWB, distinct phytoplankton blooms, dominated by different diatom species, accumulated in the PFr. Chlorophyll stocks in the sACC remained monotonously low throughout the study. Our findings confirm those of other studies that frontal regions are the major productive sites in the Southern Ocean and that input of meltwater and associated ice algae to the surface layer from a retreating ice edge is by itself an insufficient condition for induction of phytoplankton blooms. The blooms in the PFr developed under conditions of shallow mixing layers, high iron concentrations and relatively low grazing pressure. However, in all three blooms, high biomass extended to deeper than 70 m, which cannot be explained by either in situ growth or sinking out of a part of the population from the upper euphotic zone. Subduction of adjoining, shallower layers to explain depth distribution is invoked. Despite a clear CO sub(2) drawdown in the Polar Frontal region, the highly variable conditions encountered render reliable estimation of annual CO sub(2) fluxes in the Southern Ocean difficult.
AN: 4092490
24 of 71
TI: Spatial and vertical distribution of particulate dimethylsulphoniopropionate (DMSP) during spring in the Atlantic sector of the Southern Ocean
AU: Meyerdierks,-D.; Bolt,-B.; Kirst,-G.O.
AF: Univ. Bremen, FB II Meeresbotanik, Postfach 33 04 40, 28334, Bremen, Germany
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 1-2, pp. 283-297
LA: English
ER: M (Marine)
AB: Dimethylsulphoniopropionate (DMSP) concentrations in relation to phytoplankton biomass and species composition were investigated on four transects between 47 degree S and 60 degree S along 6 degree W during the SO-JGOFS cruise ANT X/6 of R.V. Polarstern in October/November 1992. Particulate DMSP concentrations at 20 m depth in the three pelagic regimes, Polar Frontal Zone, southern Antarctic Circumpolar Current and the northern rim of the Weddell Gyre, were about 25-66, 5 and 3-14 nM, respectively. DMSP:chlorophyll a ratios for the three zones were 32-92, 10-35 and 25 nmol ( mu g chl a) super(-1), respectively. In the Polar Frontal Zone, the majority of DMSP was found in the 5-20 mu m size fraction. Some DMSP was produced by algae >20 mu m (mainly diatoms), but the contribution of algae <5 mu m was negligible. As such, the Antarctic phytoplankton community sampled in the open Southern Ocean cannot be considered especially active DMSP producers compared to temperate and tropical algae.
AN: 4092483
25 of 71
TI: Physical anatomy of fronts and surface waters in the ACC near the 6 degree W meridian during austral spring 1992
AU: Veth,-C.; Peeken,-I.; Scharek,-R.
AF: Netherlands Inst. for Sea Res. N.I.O.Z., P.O. Box 59, 1790 AB, Den Burg, The Netherlands
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 1-2, pp. 23-49
LA: English
ER: M (Marine)
AB: Small-scale features of the Antarctic Circumpolar Current (ACC) along a meridional section at 6 degree W between the Polar Front and the ACC-Weddell Gyre Boundary Front are discussed using data collected during the austral spring cruise ANT X/6 of R.V. Polarstern organized within the framework of the European IGBP-JGOFS (Southern Ocean). The section covered three distinct fronts, namely the Polar Front, the Southern Polar Front (also Southern ACC Front), and the ACC-Weddell Gyre Boundary Front. Physical measurements during repeated transects over a period of 6 weeks in October/November revealed a large variability in the Polar Frontal region, indicating meandering and eddy shedding. The positions of the Southern Polar Front and the ACC-Weddell Gyre Boundary Front were observed to be far more stable than that of the Polar Front. A possible reconstruction of the meandering flow field near the Polar Front, based upon the physical observations, is presented. Details in the flow field coincide with the spatial distribution of a number of biological parameters such as phytoplankton biomass and species, and photosynthetic pigments. Although a causal relationship between them is likely, biomass enhancement cannot be understood simply in terms of macronutrients from deeper layers entering the euphotic zone, as substantiated for other oceanic frontal regions, because macronutrients do not limit phytoplankton blooms. This process, however, can be important for the micronutrient iron. Evidence is presented that the Antarctic Zone of the ACC can be subdivided into a number of spheres of influence related to the fronts. Interleaving of water is apparent between positions within such a region, but not between the regions.
AN: 4092481
26 of 71
TI: Latitudinal metazoan plankton zones in the Antarctic Circumpolar Current along 6 degree W during austral spring 1992
AU: Fransz,-H.G.; Gonzalez,-S.R.
AF: Netherlands Inst. for Sea Res. N.I.O.Z., P.O. Box 59, 1790 AB, Den Burg, The Netherlands
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 1-2, pp. 395-414
LA: English
ER: M (Marine)
AB: During the ANT X/6 cruise of R.V. Polarstern as a part of Southern Ocean JGOFS, the mesozooplankton and smaller metazoans were sampled from five depth layers between 0 and 500 m, and daily egg production was measured in copepods. The latitudinal and vertical abundance, biomass and species distribution were recorded twice along the 6 degree W meridian between the Weddell Gyre and the Polar Frontal Zone in October and November 1992. Carbon weight-length relationships are presented for the dominant copepod species Calanoides acutus, Rhincalanus gigas, Metridia gerlachei and Oithona similis. Total biomass measured by weighing filters of two size fractions and calculated from specific abundance and length estimations both averaged to about 5 g ashfree dry weight (AFDW) per m super(2) in the Polar Frontal region (PFr), somewhat lower in October than in November, and 2 g AFDW m super(-2) in the Antarctic Zone (AZ) between the PFr and the Weddell Gyre. Antarctic calanoid copepods as a group dominated biomass in both regions, but the cyclopoid copepod Oithona similis had the highest numerical abundance and in general also the highest biomass of all species. Mean copepodid abundance below 100 m was not different in the PFr and the AZ, but the abundance in the upper 100 m was much higher in the PFr. Daily egg production of Calanoides acutus was highest in the PFr. The community composition in the PFr and the AZ indicated that accumulation in the Antarctic convergence or a difference in timing of the spring rise to the surface was not the main cause of the latitudinal spring peak in the PFr. Probably the physical conditions are most favourable here for zooplankton to sustain populations. This seems most advantageous for species with a long reproductive period, allowing them to produce several generations per year. Life cycle strategies of Antarctic zooplankton species only can be compared in the framework of their specific conditions for growth and persistence in different latitudinal zones, and the distribution and transport patterns of their populations.
AN: 4092480
27 of 71
TI: Carbon export during the spring bloom at the Antarctic Polar Front, determined with the natural tracer super(234)Th
AU: Rutgers-Van-Der-Loeff,-M.M.; Friedrich,-J.; Bathmann,-U.V.
AF: Alfred-Wegener Inst. for Polar and Mar. Res., P.O. Box 120161, D27515 Bremerhaven, Germany
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 1-2, pp. 457-478
LA: English
ER: M (Marine)
AB: Profiles of particulate and dissolved super(234)Th were obtained during the JGOFS Southern Ocean expedition on R.V. Polarstern during October/November 1992. Measurements were made on three transects across the Antarctic Circumpolar Current, from the Polar Front (PF) in the north to the Weddell Sea/ACC boundary in the south. The dissolved super(234)Th/ super(238)U ratio in surface waters gradually decreased during the development of the plankton bloom at the Polar Front. In the period between the first two transects, the super(234)Th activity removed from the dissolved phase had shifted to particles that had been produced, and as a result, the total activity ratio remained unchanged. The decrease in dissolved super(234)Th corresponds with decreases in dissolved nutrients and pCO sub(2), and with increases in chlorophyll and plankton biomass. Only during the third transect was the total activity of super(234)Th clearly reduced. The super(234)Th activity missing in the upper 100 m amounted to approximately 6 x 10 super(4) dpm m super(-2) at the Polar Front. In the 22-day period between the second and third transect, the super(234)Th export flux averaged 3200 dpm m super(-2) day super(-1). The ratio of organic carbon to super(234)Th on suspended particles was lower near the Polar Front than to the south, which we attribute to the higher abundance of empty diatom frustules at the Polar Front. With an average C sub(org)/ super(234)Th ratio on suspended particles in surface water of about 20 mu mol dpm super(-1) and assuming that the C sub(org)/ super(234)Th ratio on exported particles is 30-60% of this value, we estimate that 0.43-0.86 mol C m super(-2) had been removed over the 22-day period from the surface ocean by sinking particles. Export production was negligible in the Antarctic Zone including the ice edge, but during the later stage of the bloom in the Polar Front region, it amounted to 12-24% of primary production or 25-50% of the net CO sub(2) uptake as estimated from a CO sub(2) budget.
AN: 4092477
28 of 71
TI: Grazing impact of copepods and salps on phytoplankton in the Atlantic sector of the Southern Ocean
AU: Dubischar,-C.D.; Bathmann,-U.V.
AF: Alfred-Wegener-Inst. for Polar and Mar. Res., Am Handelshafen 12, 27515 Bremerhaven, Germany
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1997 vol. 44, no. 1-2, pp. 415-433
LA: English
ER: M (Marine)
AB: During the SO-JGOFS-Polarstern cruise in October/November 1992, grazing of the dominant calanoid copepods (Calanoides acutus, Calanus propinquus and Rhincalanus gigas) and of Salpa thompsoni was determined. Calanoides acutus and R. gigas were very abundant in the Polar Frontal-region (PFr). Calanus propinquus was abundant at the ACC-Weddell Gyre Boundary (AWB). Grazing by copepods was very low and accounted for less than 1% of the primary production (PP) for all three species. Salpa thompsoni occurred in swarms in the southern part of the Antarctic Circumpolar Current (ACC) where its ingestion rates accounted for more than 100% of the PP. We conclude that grazing by copepods had a negligible effect on build-up of the phytoplankton biomass recorded in the PFr and-to a much lesser extent-at the AWB, whereas high grazing pressure of S. thompsoni was likely to have constrained phytoplankton biomass levels in the ACC.
AN: 4092475
29 of 71
TI: Reduction of iodate in seawater during Arabian Sea shipboard incubations and in laboratory cultures of the marine bacterium Shewanella putrefaciens strain MR-4
AU: Farrenkopf,-A.M.; Dollhopf,-M.E.; Chadhain,-S.N.; Luther,-G.,III; Nealson,-K.H.
AF: University of Delaware, College of Marine Studies, 700 Pilottown Road, Lewes, DE 19958, USA
SO: MAR.-CHEM. 1997 vol. 57, no. 3-4, pp. 347-354
LA: English
AB: Shipboard incubations from the US JGOFS cruise to the Arabian Sea (TN045) March, 1995 showed evidence of iodate reduction in 0.45 mu m (Gelman Supor membrane) filtered seawater samples collected from intermediate depths (200-600 m) within the oxygen minimum zone (OMZ). Inorganic chemical reduction of iodate in these samples was ruled out as no free sulfide was measurable and concentrations of ammonia and nitrite were found to be less than 5 mu M. To examine whether the reduction of iodate observed at sea could have been the result of bacterial metabolism, reduction of iodate (IO3-) to iodide (I-) by Shewanella putrefaciens strain MR-4 was studied in artificial seawater using electrochemical methods. MR-4 is a ubiquitous marine bacterium which may be of considerable importance when considering redox zonation in the water column because it is a facultative anaerobe and may switch amongst a suite of electron acceptors to support metabolism. In all experiments MR-4 reduced all iodate to iodide. The rate of formation of [I-] in the culture followed pseudo-first order kinetics. This is the first report of the marine bacterial reduction of iodate where the concentrations of iodide and iodate were measured directly. Our results may help to explain the depth distribution of iodine speciation reported in productive waters like the Arabian Sea and for the first time couple iodine speciation with bacterial productivity in the ocean.
AN: 4089414
30 of 71
TI: Phytoplankton dynamics in the upwelling-system off Coquimbo (30 degree S) through the functional relationship between photosynthesis and irradiance (P-I).
OT: Dinamica fitoplanctonica en el sistema de surgencia frente a Coquimbo (30 degree S) a traves de la relacion funcional entre fotosintesis e irradianza (P-I)
AU: Montecino,-V.; Pizarro,-G.; Quiroz,-D.
AF: Depto. de Cienc. Ecologicas, Fac. de Cienc., Univ. de Chile, Casilla 563, Santiago, Chile
SO: GAYANA-OCEANOL. 1996 vol. 4, no. 2, pp. 139-151
LA: Spanish
ER: M (Marine)
AB: The photosynthetic parameters derived from the functional relationship between photosynthesis and irradiance (P-I), were used to characterize the phytoplankton dynamics in the upwelling-system off Coquimbo (30 degree S). In vitro primary production experiments (PP) were performed with samples of different depths in coastal and oceanic stations, during seven JGOFS cruises between 1992-1994. The photosynthetic efficiency at limiting irradiance ( alpha ) was spatially (coast-ocean; within/without the upper mixing layer) independent at any time. The maximum photosynthetic rate normalized to chlorophyll a (P super(B) sub(max)) within the upper mixing layer was similar between coastal and oceanic stations (7,45 mg C mg/Cla/h) and was dependent on the original sample depth (Zor) only in the coastal area. The light gradient explains P super(B) sub(max) variability only when Zor was below the upper mixing layer. In the temporal scale P super(B) sub(max) did not change, nevertheless (was higher in autumn-winter and Ik was higher in summer. Daily PP, calculated from the photosynthetic parameters and the irradiance, varied in one order of magnitude (140-2955 mg C m super(2)/d) and was significant and inversely proportional to the depth of the upper mixed layer in the coastal stations. The spatio-temporal analysis of the photosynthetic parameters showed the conditions under which they can be considered stable, independent of the forcing factors and were indicative of the functional conditions of the phytoplankton assemblage and its dynamic in heterogeneous environments.
AN: 4068036
31 of 71
TI: New production along 140 degree W in the Equatorial Pacific during and following the 1992 El Nino event
AU: McCarthy,-J.J.; Garside,-C.; Nevins,-J.L.; Barber,-R.T.
AF: Mus. Comparative Zool., 26 Oxford St., Harvard Univ., Cambridge, MA 02138, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 1065-1093
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: This study was conducted as part of two JGOFS transects along 140 degree W between 12 degree N and 12 degree S during February-March 1992 and August-September 1992. Although its purpose was to investigate seasonal variability in nitrogenous nutrient availability and biological utilization in support of primary production, the occurrence of the 1992 El Nino during the first transect permitted us to compare El Nino and post-El Nino conditions. We had hypothesized that an El Nino-related reduction in upwelling of cold nutrient-rich water would lead to a reduction in surface nutrient concentrations and rates of new and primary production in the vicinity of the equator. However, during the height of the El Nino, NO sub(3) super(-) concentrations from 2 degree N to 7 degree S remained high enough (>2 mu mol kg super(-1)) to preclude nitrogen-limited primary production. Total nitrogen uptake rates measured 6 months after the El Nino were 2.4 times greater than those observed during the El Nino. The mean f-ratio for 2 degree N-2 degree S was slightly lower and less variable (0.06-0.13; x super(-)=0.11) during the El Nino than after (0.08-0.20; x=0.13). Over a broader meridional band (5-7 degree N to 5-8 degree S) f-ratios during the El Nino were similar to values determined in 1988, a non-El Nino year, during the same season. Significantly higher rates of new production with only a small increase in f-ratio in the period following the El Nino may constitute a more prominent feature in the ENSO cycle of equatorial biological production and export than the El Nino event per se.
AN: 4062000
32 of 71
TI: Microzooplankton grazing of primary production at 140 degree W in the Equatorial Pacific
AU: Verity,-P.G.; Stoecker,-D.K.; Sieracki,-M.E.; Nelson,-J.R.
AF: Skidaway Inst. Oceanogr., 10 Ocean Sci. Circle, Savannah, GA 31411, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 1227-1256
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: Phytoplankton growth rates and the grazing impact by microzooplankton were estimated from dilution experiments during spring and fall time-series cruises in the equatorial Pacific as part of the U.S. JGOFS program. The Time-series I (TS-I) cruise occurred during El Nino conditions, while Time-series II (TS-II) coincided with a relaxation event. Deck incubation experiments were conducted using samples from the upper mixed layer (15 m) and depths coinciding with subsurface peaks in chlorophyll a (30-60 m). Initial chlorophyll a concentrations were similar at 15 m (0.1-0.2 mu g l super(-1)) and at 60 m (0.2-0.4 mu g l super(-1)) in both cruises (experiments at 30 m were conducted only in TS-II). HPLC pigment analyses indicated that microzooplankton grazing generally balanced the daily production by prymnesiophytes, and consumed much of the daily production of picophytoplankton. However, microzooplankton apparently consumed only about half the potential production by diatoms, implying that other loss processes (macrozooplankton grazing, sinking) regulate diatom abundance in these waters. Herbivory by microzooplankton, primarily by small microflagellates and dinoflagellates, averaged 133 (15 m) to 123% (60 m) of phytoplankton growth in TS-I, and 70 (15-30 m) to 105% (60 m) in TS-II. Thus, grazing of phytoplankton by microzooplankton represented a major pathway of organic carbon transformation at the equator during El Nino and non-El Nino conditions.
AN: 4061999
33 of 71
TI: Export flux of carbon at the equator during the EqPac time-series cruises estimated from super(234)Th measurements
AU: Bacon,-M.P.; Cochran,-J.K.; Hirschberg,-D.; Hammar,-T.R.; Fleer,-A.P.
AF: Dep. Mar. Chem. and Geochemistry, Woods Hole Oceanographic Inst., Woods Hole, MA 02543, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 1133-1153
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: Distributions of super(234)Th were determined in three particle-size classes (>53, 1-53 and 0.7-1.0 mu m) and in filtered seawater during each of the two time-series cruises of the U.S. JGOFS Process Study in the equatorial Pacific. Four vertical profiles were measured on the equator at 140 degree W from the sea surface to 400 m depth between 24 March and 9 April 1992 (Time-series I) and again between 3 and 18 October 1992 (Time-series II). In addition, both organic and inorganic carbon were measured in each of the particle fractions. The results were used with a one-dimensional model, which includes the equatorial upwelling, to estimate the flux of particulate carbon sinking out of the surface layer. The flux of particulate organic carbon (POC) at the base of the euphotic zone (0.1% light level, 120 m depth) was estimated to average 1.9 mmol m super(-2) day super(-1) during El Nino (Time-series I) and 2.4 mmol m super(-2) day super(-1) during the cold period that followed (Time-series II). These values amount to only similar to 2% of the primary production measured during each of the same periods and are insufficient to balance the new production, estimated previously to be similar to 17% of primary production. These results are consistent with the hypothesis that the major part of the new production is removed from the region by advection in the form of dissolved organic matter.
AN: 4061998
34 of 71
TI: Living planktic foraminifera: Tracers of circulation and productivity regimes in the Central Equatorial Pacific
AU: Watkins,-J.M.; Mix,-A.C.; Wilson,-J.
AF: Coll. Oceanic and Atmos. Sci., Oregon State Univ., Corvallis, OR 97331, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 1257-1282
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: Planktic foraminifera (shelled protozoans from similar to 0.01 to 1 mm in size) respond to equatorial circulation and ecosystem dynamics. In the JGOFS survey I cruise of the equatorial Pacific (9 degree N-12 degree S, 140 degree W, in February-March 1992), responses to upwelling, advection, and biological activity occurred in spite of little upper-ocean temperature contrast. Rather than being abundant within the entire productive equatorial zone, foraminifera concentrated off the equator at convergent fronts. For example, non-spinose, mostly herbivorous species (G. conglomerata, G. tumida, P. obliquiloculata, and N. dutertrei) dominated near 3 degree N, in the convergence between the South Equatorial Current and the North Equatorial Countercurrent. Juvenile forms outnumbered adults within the convergence, indicating that these foraminifera succeeded and reproduced here (rather than passively accumulating by advection) perhaps by maintaining buoyancy to stay within the convergent, food-rich zone. Distributions of living foraminifera suggest that paleoceanographic transfer functions to estimate primary productivity in the geological record have merit, but controls of foraminiferal species distributions also include food stocks, light intensity, and advection.
AN: 4061997
35 of 71
TI: Export flux of particulate organic carbon from the Central Equatorial Pacific determined using a combined drifting trap- super(234)Th approach
AU: Murray,-J.W.; Young,-J.; Newton,-J.; Dunne,-J.; Chapin,-T.; Paul,-B.; McCarthy,-J.J.
AF: Sch. Oceanogr., Box 357940, Univ. Washington, Seattle, WA 98195-7940, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 1095-1132
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: The export flux of particulate organic carbon from the euphotic zone in the central equatorial Pacific was measured using an approach that utilizes super(234)Th and organic carbon analyses on water column and drifting sediment trap samples. This study was conducted as part of the U.S. Joint Global Ocean Flux Study (U.S. JGOFS) EqPac process study from 12 degree N to 12 degree S at 140 degree W. Samples were collected during the Survey I (February-March 1992) and Survey II (August-September 1992) cruises. The accuracy of drifting sediment traps was evaluated by comparing the measured flux of super(234)Th with the flux calculated from the deficiency of super(234)Th relative to super(238)U in the water column. The flux of particulate organic carbon (POC) was calculated as the product of the calculated flux of super(234)Th times the organic carbon/ super(234)Th ratio in trap samples. Assuming that the organic carbon/ super(234)Th ratio in trap samples was representative of sinking particles, we used an average value for the organic carbon/ super(234)Th ratio for each station.
AN: 4061996
36 of 71
TI: Beam attenuation and micro-organisms: Spatial and temporal variations in small particles along 140 degree W during the 1992 JGOFS EqPac transects
AU: Chung,-Sung-Pyo; Gardner,-W.D.; Richardson,-M.J.; Walsh,-I.D.; Landry,-M.R.
AF: Dep. Oceanogr., Texas A & M Univ., College Station, TX 77843, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 1205-1226
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: As part of the U.S. JGOFS EqPac program, transmissometer profiles were made from 12 degree N to 12 degree S at 140 degree W during February-March (cruise TT007) and August-September (cruise TT011) 1992. Meridional sections of c sub(p) (beam attenuation due to particles) were prepared by selecting profiles made at a specific time during the day ( similar to 18:00 h) to reduce the influence of diel variability and to facilitate point-to-point comparisons with other variables (e.g. T, nitrate, bioabundance, etc.). A tight correlation between beam c sub(p) and total scattering cross-section of micro-organisms was observed, suggesting that heterotrophic bacteria, prochlorophytes, cyanobacteria and small autotrophic eukaryotes (all < 3 mu m) were dominant contributors to beam c sub(p). Size-filtration experiments also confirmed that small particles (< 8 mu m) accounted for 41-89% of the c sub(p) signal in the equatorial Pacific. Contributions of the bacterial fraction and detrital material were assessed. Three biohydrographic regimes [northern (7 degree -12 degree N), equatorial (5 degree N-5 degree S) and southern (7 degree -12 degree S)] could be distinguished from characteristic profiles of c sub(p) and other variables. While the northern and southern regimes remained relatively constant in c sub(p) between El Nino (TT007) and cold surface water (TT011) conditions, the equatorial regime showed >30% increase in surface beam c sub(p) and IBAC (integrated beam attenuation coefficient) during TT011 compared to TT007. This suggests that only the equatorial regime responds sensitively to the hydrodynamic factors (e.g. upwelling, currents, El Nino, tropical instability waves, etc.) regulating particle distributions. The c sub(p):chlorophyll a ratio, a proxy for the C.chlorophyll a ratio, also was calculated to obtain insight into biogeochemical cycles in the upper waters of the equatorial Pacific.
AN: 4061995
37 of 71
TI: Particulate barium fluxes and their relationships to biological productivity
AU: Dymond,-J.; Collier,-R.
AF: Oregon State Univ., Coll. Oceanic and Atmos. Sci., Corvallis, OR 97331, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 1283-1308
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: To understand better the processes that control the transport of particulate barium through the water column and its preservation in marine sediments, we measured particulate barium fluxes along an equatorial transect at 140 degree W using moored sediment traps. The fluxes of barium correlate strongly with the fluxes of organic carbon; however, this relationship is non-linear - higher carbon fluxes have proportionately less associated barium. As a result we observe spatial and temporal variations of roughly a factor of three in the barium-to-organic carbon ratio. Understanding this variability may help to define the processes that determine the geochemical behavior of Ba in the oceans. Several hypotheses that could influence the flux of Ba and its relationship to organic carbon flux have been proposed: barite formation in barium- and sulfate-enriched microenvironments formed during particle settling; lateral advection of carbon and barium from continental margins; the influence of seawater barium concentration; and Ba scavenging by aluminosilicates. Our study reveals temporal variability in the Ba/C sub(org) values that occurs over timescales of less than one month. Also, depth profiles of carbon and Ba fluxes show that the variability originates at depths less than 1200 m and is conveyed throughout the water column. Both the rapid changes and the upper water column origin of the signals point to upper-ocean biological processes as the predominant cause of the variability in the barium-to-organic carbon ratios. We also observe, however, a 25% increase in Ba flux below 1200 m. The deep sources of Ba could result from barite formation linked to continued organic carbon degradation or from lateral sources of particulate barium. Because the spatial and temporal changes in Ba/C sub(org) values correlated to changes in particulate opal and organic carbon fluxes, ocean ecology appears to have an important influence on barium fluxes. A better understanding of the processes that contribute to the particulate barium flux is needed before the accumulation of barium in marine sediments can be used as a quantitative proxy for ocean productivity.
AN: 4061994
38 of 71
TI: Spatial and temporal variability of total organic carbon along 140 degree W in the Equatorial Pacific Ocean in 1992
AU: Peltzer,-E.T.; Hayward,-N.A.
AF: Mar. Chem. and Geochemistry Dep., Woods Hole Oceanographic Inst., Woods Hole, MA 02543, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 1155-1180
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: Total organic carbon (TOC) was analyzed on four transects along 140 degree W in 1992 using a high temperature combustion/discrete injection (HTC/DI) analyzer. For two of the transects, the analyses were conducted on-board ship. Mixed-layer concentrations of organic carbon varied from about 80 mu M C at either end of the transect (12 degree N and 12 degree S) to about 60 mu M C at the equator. Total organic carbon concentrations decreased rapidly below the mixed-layer to about 38-40 mu M C at 1000 m across the transect. Little variation was observed below this depth; deep water concentrations below 2000 m were virtually monotonic at about 36 mu M C. Repeat measurements made on subsequent cruises consistently found the same concentrations at 1000 m or deeper, but substantial variations were observed in the mixed-layer and the upper water column above 400 m depth. Linear mixing models of total organic carbon versus sigma sub( theta ) exhibited zones of organic carbon formation and consumption. TOC was found to be inversely correlated with apparent oxygen utilization (AOU) in the region between the mixed-layer and the oxygen minimum. In the mixed-layer, TOC concentrations varied seasonally.
AN: 4061993
39 of 71
TI: Neutral carbohydrate geochemistry of particulate material in the Central Equatorial Pacific
AU: Hernes,-P.J.; Hedges,-J.I.; Peterson,-M.L.; Wakeham,-S.G.; Lee,-C.
AF: Sch. Oceanogr., Univ. Washington, Box 357940, Seattle, WA 98195-7940, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 1181-1204
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: Neutral carbohydrate compositions were determined for particulate samples from plankton net tows, shallow floating sediment traps, mid-depth and deep moored sediment traps, and sediment cores collected along a north-south transect in the central equatorial Pacific Ocean during the U.S. JGOFS EqPac program. Total neutral carbohydrate depth profiles and patterns along the transect follow essentially the same trends as bulk and organic carbon (OC) fluxes-attenuating with depth, high near the equator and decreasing poleward. OC-normalized total aldose (TCH sub(2)O) yields along the transect and with depth do not show any consistent patterns. It appears that compositional signatures of neutral carbohydrates in sediments are more dependent upon their planktonic source than on any particular diagenetic pathway. Based on weight per cent glucose, comparisons of samples between Survey I (El Nino) and Survey II (non-El Nino) indicate that during Survey I, organic material in the epipelagic zone in the northern hemisphere may have undergone more degradation than organic material in the southeastern hemisphere.
AN: 4061992
40 of 71
TI: Distribution of polycystine radiolaria and their relation to the physical environment during the 1992 El Nino and following cold event
AU: Welling,-L.A.; Pisias,-N.G.; Johnson,-E.S.; White,-J.R.
AF: Coll. Oceanic and Atmos. Sci., Oregon State Univ., Ocean Admin. Bldg. 104, Corvallis, OR 97331-5503, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 1413-1434
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: Radiolarian density and composition were determined for two transects from 12 degree N to 12 degree S along 140 degree W to evaluate the relationship between species distribution and physical conditions in the Equatorial Pacific. Highest standing stocks were measured during the U.S. JGOFS Equatorial Pacific Survey II cruise (August 1992) at 2 degree N in association with a convergent, tropical instability wave front. Radiolaria accumulate at the surface of the front and subduct to at least 100 m depth and over 100 km to the north. Standing stocks measured during Survey I (February/March), when El Nino conditions prevailed, were lower and less patchy than during Survey II. Radiolarian compositional data are evaluated using Q-mode factor analysis. These results indicate radiolarian distribution in the Equatorial Pacific is primarily controlled by ocean circulation with sea-surface temperature of secondary importance.
AN: 4061979
41 of 71
TI: Origin and maintenance of a high nitrate condition in the Equatorial Pacific
AU: Chai,-Fei; Lindley,-S.T.; Barber,-R.T.
AF: Dep. Oceanogr., Univ. Maine, Orono, ME 04469-5741, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 1031-1064
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: The physical and biological causes for the equatorial nutrient anomaly were investigated using an ecosystem model embedded within an ocean general circulation model to determine the nitrate budget for the equatorial Pacific Ocean. In the 140 degree W region the effects of mixing on nitrate concentration were small compared to the effects of advection; upwelling and zonal transport to the east in the Equatorial Undercurrent were the major processes in the nitrate budget. At 140 degree W on the equator annual J sub(NO3), the total net physical supply of nitrate to the euphotic layer, was 3.76 mmol m super(-2) day super(-1); the vertical integrated (0-120 m) new production calculated from the ecosystem model was 3.36 mmol m super(-2) day super(-1) or, in carbon units, 22.26 mmol C m super(-2) day super(-1). The vertical supply of nitrate (-w partial differential NO sub(3)/ partial differential z) due to the upwelling is controlled by two factors, the vertical velocity and vertical gradient of nitrate concentration. The vertical velocity reaches the maximum during climatological fall, but the vertical gradient of nitrate is weaker in the fall. Therefore, the vertical supply of nitrate is smaller than in spring. To investigate the role of physiological limitation of phytoplankton photosynthesis and specific growth rate on the maintenance of the high nutrient-low chlorophyll (HNLC) condition, a model experiment was performed that included, unchanged from previous model runs, the physical conditions and density-dependent grazing function, but greatly reduced physiological limitations by increasing alpha (initial slope of P-I and curve) and P sub(max) (maximum specific growth rate) values. When this was done, vertical integrated primary production at 140 degree W on the equator doubled (from 83 to 166 mmol C m super(-2) day super(-1)), but the zooplankton grazing on the phytoplankton also doubled (from 75 to 150 mmol C m super(-2) day super(-1)). Zooplankton biomass doubled, but there was only a slight increase in phytoplankton biomass; no phytoplankton bloom formed in this model experiment. With potential physiological limitations of phytoplankton rates greatly reduced, the characteristic equatorial plume of unused surface layer nitrate still persisted; but the nitrate-rich plume was smaller in horizontal extent and the maximum concentration was reduced by half from observed concentrations. While the reduction in the extent of the nitrate-rich plume indicates that physiological limitation plays a significant role in the maintenance of the nutrient anomaly, its persistence demonstrates that physical processes and grazing also are involved.
AN: 4061973
42 of 71
TI: Phytodetritus at the abyssal seafloor across 10 degree of latitude in the Central Equatorial Pacific
AU: Smith,-C.R.; Hoover,-D.J.; Doan,-S.E.; Pope,-R.H.; Demaster,-D.J.; Dobbs,-F.C.; Altabet,-M.A.
AF: Dep. Oceanogr., Univ. Hawaii, 1000 Pope Rd., Honolulu, HI 96822, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 1309-1338
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: Fresh phytoplankton detritus (or phytodetritus) has been reported from numerous deep seafloor sites in the temperate North Atlantic and Pacific Oceans following seasonal phytoplankton blooms. Here we report the first strong evidence for abyssal accumulations of phytodetritus in the tropics, in the central equatorial Pacific. In November-December 1992 we obtained photographs and/or sediment-core samples from 61 abyssal stations (water depths of 4280-5012 m) between 12 degree S and 9 degree N along similar to 140 degree W. Greenish flocculent material was recovered from the top of multiple-core samples from 5 degree S to 5 degree N. Microscopic examination of greenish material recovered from core tops and a burrow lumen revealed relatively intact diatoms (including Rhizosolenia sp.) and other microalgae with chloroplasts containing chlorophyll. The greenish material was 1-12.5% organic carbon by weight, i.e. 5-39 times richer than associated seafloor sediments. We conclude that fresh, organic-rich phytodetritus was present on the seafloor from 5 degree S to 5 degree N along 140 degree W in November-December 1992, with highest concentrations within 2-3 degree of the equator. Because the degradation rate of this material appears to be very high, its presence at the seafloor for several months per year could yield significant phytodetrital contributions to the annual seafloor organic-carbon budget.
AN: 4061972
43 of 71
TI: Early diagenesis of organic material in Equatorial Pacific sediments: Stoichiometry and kinetics
AU: Hammond,-D.E.; McManus,-J.; Berelson,-W.M.; Kilgore,-T.E.; Pope,-R.H.
AF: Dep. Earth Sci., Univ. Southern California, Los Angeles, CA 90089-0740, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 1365-1412
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: Benthic incubation chambers and sediment pore water profiles were used to study early diagenesis of organic matter in equatorial Pacific sediments. Replicate measurements with a flux chamber covering 720 cm super(2) indicated that the spatial variability of oxygen, TCO sub(2), alkalinity, nitrate and silica fluxes at a single station did not exceed 10-35%. In contrast, diffusive fluxes of oxygen from replicate cores covering 70 cm super(2) at a single station often showed greater variation. The aerally-integrated benthic respiration rate for the equatorial Pacific upwelling region is at least 25% of the integrated respiration rate for the continental margin (slope + rise) areas of the Pacific, emphasizing the importance of the equatorial Pacific sediments as a major site of benthic carbon recycling. Benthic carbon remineralization rates determined during the past decade near the equator and 140 degree W have varied by a factor of 2, which is not surprising given the short lifetime of the majority of the carbon degrading. The temporal patterns of carbon remineralization rates resemble those of sea-surface temperature, suggesting that benthic carbon oxidation at this site may reflect water column productivity over relatively short timescales.
AN: 4054404
44 of 71
TI: Rapid bioturbation in Equatorial Pacific sediments: Evidence from excess super(234)Th measurements
AU: Pope,-R.H.; Demaster,-D.J.; Smith,-C.R.; Seltmann,-H.,Jr.
AF: Dep. Mar., Earth, and Atmos. Sci., North Carolina State Univ., Raleigh, NC 27695-8208, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 1339-1364
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: In order to evaluate bioturbation in Equatorial Pacific sediments, profiles of excess super(234)Th were measured in cores collected during November and December 1992, at six abyssal sites along the JGOFS Equatorial Pacific 140 degree W transect, from 5 degree S to 9 degree N. Excess super(234)Th (half-life = 24.1 days) was detected at all sites. Mean inventories ranged from a low of 0.25 dpm cm super(-2) at 9 degree N, to a high of 2.6 dpm cm super(-2) at 2 degree N. Eddy-diffusive models of the excess super(234)Th profiles suggest that, on 100-day timescales, particle mixing is slow at 5 degree S and 2 degree S (eddy diffusion coefficient, D sub(b), <0.4 cm super(2) year super(-1)), faster at 0 degree and 2 degree N (D sub(b) = 0.34-4.8 cm super(2) year super(-1)), and fastest at 5 degree N (D sub(b) = 4.7-11 cm super(2) year super(-1)). These results suggest that measurements on a single core may not fully characterize the sediment mixing regime in a particular region, and highlight the need for multiple samples from an individual site. Models of early diagenesis in deep-sea sediments may need to incorporate both non-diffusive transport terms and rapid biodiffusive mixing of recently-deposited particles.
AN: 4054403
45 of 71
TI: [Amino acids in the North Atlantic: Particle composition and remineralisation]
OT: Aminosaeuren im Nordatlantik: Partikelzusammensetzung und Remineralisierung
AU: Lundgreen,-U.
SO: BER.-INST.-MEERESKD.-CHRISTIAN-ALBRECHTS-UNIV.-KIEL 1996 no. 283, 128 pp
NT: Incl. bibliogr.: 197 refs.
LA: German
ER: M (Marine)
AB: The present investigation was conducted in the framework of the internationally coordinated Joint Global Ocean Flux Study (JGOFS). The major aim is to get information about the processes of production, remineralisation and export of marine particles. Amino acids may be appropriate tracers. For that purpose, particles were sampled at three JGOFS sites in the North Atlantic between 33 degree N and 54 degree N and analyzed for their amino acid content and composition. The total amino acid flux varies seasonally resulting from variations in particle flux and particle amino acid content. The changes in amino acid content are related to the changes in particle composition (CaCO sub(3), opal, total chlorophyll and the CaCO sub(3)/opal ratio). This reflects the seasonal changes in plankton community structure at the euphotic zone, which is the area of origin of the particles collected. The major change from more phytoplankton derived particles to more zooplankton derived particles is also reflected in the amino acid composition of the sediment trap material. This was observed from cluster analysis of the appropriate data.
AN: 4053935
46 of 71
TI: Picophytoplankton abundance and biomass in the western Tropical Pacific Ocean during the 1992 El Nino year: Results from flow cytometry
AU: Blanchot,-J.; Rodier,-M.
AF: Groupe FLUPAC-JGOFS, Cent. ORSTOM, Bp A5, Noumea Cedex, New Caledonia
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1996 vol. 43, no. 6, pp. 877-896
LA: English
ER: M (Marine)
AB: Natural populations of phytoplankton from the western Tropical Pacific Ocean were analyzed by flow cytometry from a transect along 165 degree E between 20 degree S and 7 degree N. The abnormal hydrological situation corresponded to a weak El Nino event, with no equatorial upwelling and a marked nutrient ridge centered on 10 degree S. Prochlorophytes dominated numerically everywhere along the vertical, whatever the depth, in the 0-160-m layer (96% of cell abundance). Paradoxically, the highest concentrations, up to 4.4 x 10 super(5) cells ml super(-1), were found in oligotrophic waters (< 0.1 mu M NO sub(3)). In contrast, the highest concentrations of orange cyanobacteria and red-fluorescing picoeukaryotes were observed when nitrate was present in the photic layer, i.e. around 10 degree S (up to 6.4 x 10 super(4) cells ml super(-1) and 1.3 x 10 super(4) cells ml super(-1)), and, to a lesser extent in the vicinity of the deep nitracline north of 8 degree S. Along the transect we encountered two hydrological situations, characterized by different community structures. The first one, found from 15 degree S to 7 degree N, except at 10 degree S, was a two-layer structure (Typical Tropical Structure, TTS) defined by a strong pycnocline in the upper 180 m and a well-marked nitracline. In this region, Prochlorococcus and picoeukaryotes co-dominated the 180-m integrated fluorescence and carbon biomass, but Prochlorococcus were the major component in the upper nitrate-depleted layer, while picoeukaryotes dominated the underlying rich layer. Inversely, Synechococcus were a relatively minor contributor to fluorescence ( similar to 4%) and phytoplankton biomass (< 1%) in comparison to the other cell types. The second structure observed in the southernmost part of the transect (20 degree S-16 degree S) was defined by the absence of a density gradient, and therefore by deep vertical mixing. In this case, the concentration of Prochlorococcus in the upper nitrate-depleted layer was reduced, whereas Synechococcus percentage contribution in the upper 180 m was significantly higher than in the TTS (> 30% of total fluorescence and similar to 4% of carbon biomass). According to our results, we discuss the expected role of each phytoplankton group in the regenerated and new production. Finally, we discuss the importance of cell size as a factor in the expected roles of the different phytoplankton groups in the carbon sink.
AN: 4044865
47 of 71
TI: Distribution, abundance and size composition of heterotrophic dinoflagellates and ciliates in the Sargasso Sea near Bermuda
AU: Lessard,-E.J.; Murrell,-M.C.
AF: Sch. Oceanogr., Univ. Washington, Box 357940, Seattle, WA 98195, USA
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1996 vol. 43, no. 7, pp. 1045-1065
LA: English
ER: M (Marine)
AB: We examined the temporal variability in vertical distribution, abundance, size composition and biomass of heterotrophic dinoflagellates and ciliates at the JGOFS time-series station off Bermuda during August 1989 and March-April 1990. Abundances of heterotrophic dinoflagellates and ciliates ranged from 1.3 to 14.2/ml in August and 2.0 to 28.6/ml in number in March-April. Total biomass of these two groups ranged from 0.2 to 2.9 mu g C/l; integrated euphotic zone biomass was twice as high in March-April than in August. Heterotrophic dinoflagellates were always more numerous than ciliates (0.9-28.6/ml compared to 0.1-5.0/ml). On average, heterotrophic dinoflagellates constituted 50% of the total biomass of these two groups (46-59% in August and 29-64% in March-April) in the upper 150 m. Greater than 92% of the dinoflagellate cells were < 20 mu m in size, but larger cells generally dominated the biomass. The proportion of ciliates < 20 mu m in size was highly variable between samples (range = 8-91%, mean = 59%), but small cells were, on average, only 18% of the ciliate biomass. The temporal variability in taxonomic composition of these two groups was high, reflecting the mesoscale physical variability found in this transition region. This is the first report of the biomass and composition of the > 5 mu m heterotrophic protists in the oligotrophic subtropical Sargasso Sea.
AN: 4041021
48 of 71
TI: Spatial and temporal variability of phytoplankton pigment distributions in the Central Equatorial Pacific Ocean
AU: Bidigare,-R.R.; Ondrusek,-M.E.
AF: Dep. Oceanogr., Sch. Ocean and Earth Sci. and Technol., Univ. Hawaii, Honolulu, HI 96822, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 809-833
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: During the 1992 U.S. JGOFS Equatorial Pacific (EqPac) study, we participated in survey (12 degree N-12 degree S, along 135 degree -140 degree W) and time-series (0 degree , 140 degree W) cruises to identify the factors that control spatial and temporal variations in phytoplankton pigment biomass, taxonomic composition and size structure. To achieve this goal, we determined pigment marker distributions in conjunction with collaborative measurements performed by EqPac investigators. Distributions of phytoplankton pigments measured during early 1992 (El Nino conditions) were different from those measured during late 1992 ("normal" conditions). Most notably, the accessory pigment distributions revealed that the 1991-1992 El Nino event produced a significant reduction in eukaryotic phytoplankton biomass, especially that contributed by prymnesiophytes, pelagophytes and diatoms. This variability was most likely caused by a combination of physical (Kelvin waves, tropical instability waves and advection), chemical (iron limitation) and biological (growth-grazing imbalances) processes. The results of this pigment study underscore the need for sampling biological properties on the appropriate time and space scales, and the necessity of physical measurements for interpreting their distributions.
AN: 4041011
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TI: Micro- and mesoprotozooplankton at 140 degree W in the Equatorial Pacific: Heterotrophs and mixotrophs
AU: Stoecker,-D.K.; Gustafson,-D.E.; Verity,-P.G.
AF: Univ. Maryland System, Cent. for Environ. and Estuarine Stud., Horn Point Environ. Lab., PO Box 775, Cambridge, MD 21613, USA
SO: AQUAT.-MICROB.-ECOL. 1996 vol. 10, no. 3, pp. 273-282
LA: English
ER: M (Marine)
AB: Abundance, biomass and presence or absence of plastids in micro- (>20 to 200 mu m) and meso- (>200 mu m to 2 mm size range) protozooplankton were determined during March-April and October 1992 at 140 degree W on the equator as part of the United States' participation in the Joint Global Ocean Flux Study (JGOFS). The March-April cruise took place during strong El Nino conditions but the October 1992 cruise was during a relaxation in El Nino. Protistan zooplankton biomass in the 20 to 64 mu m size range was dominated by planktonic ciliates, in the >64 to 200 mu m size range by ciliates, heterotrophic dinoflagellates, foraminifera and acantharia, and in the >200 mu m size range by acantharia, foraminifera and polycystine radiolaria. Presence of algal plastids, indicating mixotrophic nutrition, was common. In October, plastidic cells contributed similar to 27, 47 and 56% of the protozooplankton biomass in the 20-64, >64-200 and >200 mu m size classes, respectively. During October, the protistan micro- and mesozooplankton biomass was generally higher than in March-April 1992. Most of the increase in biomass was due to ciliates and foraminifera. These data suggest that the numerical responses of ciliates may be important in coupling changes in primary productivity of nanoplankton to their removal by grazing in the equatorial Pacific. The increased biomass of foraminifera in October may be linked to the relaxation in El Nino. Foraminifera may be particularly important in the coupling between primary production and biogenic flux of organic carbon and carbonate in the equatorial Pacific.
AN: 4040838
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TI: Abundances and distributions of picoplankton populations in the Central Equatorial Pacific from 12 degree N to 12 degree S, 140 degree W
AU: Landry,-M.R.; Kirshtein,-J.; Constantinou,-J.
AF: Dep. Oceanogr., Univ. Hawaii at Manoa, 1000 Pope Rd., Honolulu, HI 96822, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 871-890
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: Abundances and distributions of picoplankton were studied on two cross-equatorial transect cruises (12 degree N, 140 degree W-12 degree S, 135 degree W) during February-March (TT007) and August-September 1992 (TT011). Samples were collected in the upper 200 m from early-morning and late-afternoon hydrocasts at 15 stations on each cruise (60 depth profiles, 820 samples). Populations of heterotrophic bacteria, Prochlorococcus, Synechococcus and small autotrophic eukaryotes were enumerated by dual-beam flow cytometry. At the northern end of the transect (7-12 degree N), abundances and vertical distributions were similar to those reported for the oligotrophic North Pacific gyre, with Prochlorococcus and heterotrophic bacteria dominating in the upper euphotic zone, and Synechococcus and eukaryotes exhibiting peaks in cell abundance at depth. All populations were abundant throughout the euphotic zone close to the equator and at the southern end of the transect. Heterotrophic bacteria and Synechococcus were generally more abundant in late-afternoon hydrocasts. The diel enhancement followed the temporal pattern in beam c and suspended particulates, and was particularly strong in the equatorial upwelling region where it averaged 13.6% of the morning population for heterotrophic bacteria and 22.3% for Synechococcus. Conservative estimates of daily growth rates from these data are 0.25 and 0.40 day super(-1), respectively, for the two populations. Near-surface maxima in heterotrophic bacteria were symmetrical around the equator, centered around 5 degree S and 5 degree N. Prochlorococcus was most abundant during local summer conditions at the respective ends of the transect. A minimum occurred in association with a dense aggregation of buoyant diatoms at the convergent front of a tropical instability wave (2 degree N, TT011). The ratio of Prochlorococcus to total bacteria was generally in the range of 0.15-0.2 for the upper water column, but varied during TT011 from >0.3 for the most northern stations to <0.1 at the 2 degree N front. At higher latitudes, Synechococcus was more numerous during El Nino conditions (TT007) on both sides of the equator and at southern stations on both cruises. Autotrophic eukaryotes were more abundant during local winters at the ends of the transect and during the "cold tongue" conditions (TT011) at the equator. Picoplankton account for most of the chlorophyll biomass and primary production in the central equatorial Pacific. Nonetheless, their abundances and distributions are relatively stable and conservative while other populations, such as diatoms, respond more dramatically to environmental forcing.
AN: 4040491
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TI: Phytoplankton variability in the central and eastern tropical Pacific
AU: Chavez,-F.P.; Buck,-K.R.; Service,-S.K.; Newton,-J.; Barber,-R.T.
AF: Monterey Bay Aquarium Res. Inst., Box 628, Moss Landing, CA 95039, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 835-870
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: An extensive set of measurements of phytoplankton production, biomass and composition, and microzooplankton grazing from the coast of Peru to 170 degree W during 1992, together with similar data collected over the previous decade, has allowed recalculation of the primary production supported by equatorial upwelling and improved description of the variability in phytoplankton properties. Equatorial region surface chlorophyll and phytoplankton biomass were low, averaging 0.2 mu g l super(-1) and 20 mu g Cl super(-1), respectively, and showed low variance. Phytoplankton in the open ocean of the tropical Pacific were dominated by small (<5 mu m) solitary organisms, primarily prochlorophytes, Synechococcus, eukaryotic picoplankton, haptophytes and dinoflagellates, while coastal populations were dominated by larger organisms or colonies (primarily diatoms). At a few open ocean locations high numbers of diatoms were found. The chlorophyll maximum observed in the equatorial Pacific was a function of increased chlorophyll per cell rather than an increase in cell numbers. Surface phytoplankton carbon to chlorophyll was highly variable and a function of available irradiance and upwelling strength. On the order of 40% of the particulate nitrogen retained by GF/F filters was estimated to be phytoplankton nitrogen. Phytoplankton growth rate estimates using daily carbon uptake and phytoplankton carbon estimated from microscopic enumeration ranged from 0.55 to 0.70 day super(-1). Estimates of growth rates from dilution experiments gave estimates of the order of 1 day super(-1) and microzooplankton grazing rates that were significantly lower, 0.4 day super(-1). The mean mass specific grazing rate for microzooplankton was estimated to range from 1.6 to 1.8 day super(-1). The mean productivity for the equatorial Pacific from 90 degree to 180 degree W, 5 degree N-5 degree S, was estimated to be 900 mg C m super(-2) day super(-1) for the period from 1990 to the present, twice that estimated previously. The maximum f-ratio (new to total production) was estimated to be 0.36. Assuming that between 25 and 50% of the upwelled nitrate is never taken up by phytoplankton between 5 degree N and 5 degree S, new production would be 162-244 mg C m super(-2) day super(-1) and f would range from 0.18 to 0.27.
AN: 4040490
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TI: Primary productivity and its regulation in the equatorial Pacific during and following the 1991-1992 El Nino
AU: Barber,-R.T.; Sanderson,-M.P.; Lindley,-S.T.; Chai,-Fei; Newton,-J.; Trees,-C.C.; Foley,-D.G.; Chavez,-F.P.
AF: Nicholas Sch. Environ., Duke Univ., Beaufort, NC 28516, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 933-969
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: The cycling of carbon in the equatorial Pacific Ocean was investigated by the Equatorial Pacific (EqPac) Study in 1992. As part of that study in situ primary productivity was measured on survey and time-series cruises along 140 degree W from 12 degree N to 12 degree S with methods determined to be trace-metal clean. Primary productivity, chlorophyll and chlorophyll-specific productivity rates varied coherently in relation to two large-scale features: temporally, primary productivity was reduced during the El Nino dominated period (February-April 1992) and increased during the cool period (August-October 1992); and spatially enhanced primary productivity persisted close to the equator relative to the oligotrophic regions poleward of 10 degree N and 10 degree S. On the equator in October 1992 during the period of relatively cool water, primary productivity was about twice (125 mmol C m super(-2) day super(-1)) the value during the peak warm period (60 mmol C m super(-2) day super(-1)). The climatological mean equatorial productivity in the cold tongue has been recalculated to be about 75 mmol C m super(-2) day super(-1) (Chavez et al., 1996). The mean 1992 productivity on the equator (1 degree S-1 degree N) was about 25% higher than climatology (95 vs 75 mmol C m super(-2) day super(-1)) and about 3 times the value in oligotrophic waters poleward of 10 degree N and 10 degree S (95 vs 30 mmol C m super(-2) day super(-1)). Higher chlorophyll-specific productivity during the cool period relative to the warm period (3.9 vs 2.4 mmol C mg chl super(-1) day super(-1)) indicates that the increase in absolute productivity did not result solely from a biomass increase, but from a change in the nutrient-regulated specific productivity rate. The regulating nutrient was not a macronutrient, such as nitrate or silicic acid, because macronutrients (and light) were present in uptake-saturating concentrations during both the warm and cool periods of the 1992 EqPac study. Physiological constraint by a micronutrient, such as iron, is implicated as the factor regulating these productivity variations. The change in iron supply resulted from a change in equatorial circulation processes. During the warm period, El Nino-Southern Oscillation (ENSO)-driven changes in pycnocline topography depressed the Equatorial Undercurrent (EUC), thereby decreasing the amount of iron-rich EUC water entrained into equatorial upwelling and vice versa during the cool period. During the August-October cool period of generally increased productivity, two further episodic increases in specific productivity, biomass and diatom abundance occurred during intense and remotely forced upwelling events associated with a front or the passage of a frontal wave. In both mesoscale episodes, temperature and salinity show that the intensified upwelling reached more deeply into the already relatively shallow EUC. Productivity and biomass increases during both of these events were quantitatively similar to those in an in situ iron addition experiment (IronEx) carried out in equatorial Pacific waters in 1993. Variations in the supply of upwelled iron provided by the iron-rich EUC best account for the warm-cool period difference in phytoplankton productivity as well as the episodic increases in specific productivity, biomass and diatom abundance during intense mesoscale upwelling events seen in the dynamic equatorial region in the EqPac study.
AN: 4040487
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TI: Calcification rates in the equatorial Pacific along 140 degree W
AU: Balch,-W.M.; Kilpatrick,-K.
AF: Bigelow Lab. for Ocean Sci., P.O. Box 475, McKown Point, W. Boothbay Harbor, ME 04575, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 971-993
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: The calcite standing stock, calcification rate, concentrations of detached coccoliths and plated coccolithophore cells were determined in the equatorial Pacific along 140 degree W, between 12 degree N and 12 degree S latitude, during August and September 1992. Continuous surface optical and fluorescence measurements were also taken along this transect. Integrated calcification ranged between 3 and 12% of the total carbon fixed into particulate matter. Calcification exceeded 50% of the total fixed carbon (per unit volume) at specific depths from the northern-most oligotrophic stations. A pronounced subsurface peak in suspended calcite was noted near the equator. Calcification was considerably more patchy than photosynthesis. Normalizing the calcification rates to the surface area of calcite-producing species provided an estimate of the extracellular calcite flux rates. These results showed that the populations from the equator to 3 degree N at 60 m depth, and near the surface from the equator to 9 degree S were the most active calcite producers. Underway estimates of light scattering showed the importance of upwelling for bringing cold, clear, relatively particle-free water to the surface, followed by growth and calcite production as the water warmed. When temperatures reached their upper range (about 28.8 degree C), light scattering decreased again, presumably as growth slowed and particles sank. Integrated calcification estimates averaged over the equatorial region were compared to sediment trap data; the results suggest significant disappearance of calcite particles in the top 1000 m, above the lysocline. One hypothesis to explain this is that dissolution occurred in microzones where decomposition of reduced organic matter lowered the pH sufficiently to dissolve calcite.
AN: 4040486
54 of 71
TI: Iron deficiency and phytoplankton growth in the Equatorial Pacific
AU: Fitzwater,-S.E.; Coale,-K.H.; Gordon,-R.M.; Johnson,-K.S.; Ondrusek,-M.E.
AF: Moss Landing Mar. Labs., P.O. Box 450, Moss Landing, CA 95039, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 995-1015
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: Several experiments were conducted in the equatorial Pacific at 140 degree W during the Joint Global Ocean Flux Study, equatorial Pacific, 1992 Time-series I (TS-I, 23 March-9 April), Time-series II (TS-II, 2-20 October) and FeLINE II cruises (10 March-14 April), to investigate the effects of added Fe on phytoplankton communities. Seven series of deckboard iron-enrichment experiments were performed, with levels of added Fe ranging from 0.13 to 1000 nM. Time-course measurements included nutrients, chlorophyll a and HPLC pigments. Results of these experiments showed that subnanomolar (sub-nM) additions of Fe increased net community specific growth rates, with resultant chlorophyll a increases and nutrient decreases. Community growth rates followed Michaelis-Menten type kinetics resulting in maximum rates of 0.99 doublings per day and a half-saturation constant of 0.12 nM iron. The dominant group responding to iron enrichment was diatoms.
AN: 4040485
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TI: Iron-enrichment bottle experiments in the Equatorial Pacific: Responses of individual phytoplankton cells
AU: Zettler,-E.R.; Olson,-R.J.; Binder,-B.J.; Chisholm,-S.W.; Fitzwater,-S.E.; Gordon,-R.M.
AF: Biol. Dep., Woods Hole Oceanographic Inst., Woods Hole, MA 02543, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 1017-1029
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: Iron-enrichment bottle experiments were monitored using flow cytometry to investigate the hypothesis that phytoplankton in the equatorial Pacific are iron-limited. Iron-enriched Synechococcus, ultraphytoplankton, nanophytoplankton, pennate diatoms, and coccolithophorids had higher fluorescence and/or forward light scatter per cell than control cells; for Prochlorococcus the trends were the same although the differences were not significant. This suggests that most phytoplankton cells were physiologically affected by the low iron concentrations in this region. However, only pennate diatoms showed significant increases in cell concentrations due to iron enrichment. The sum of chlorophyll fluorescences of individual cells measured by flow cytometry yielded patterns similar to those of extracted bulk chlorophyll, with increases of up to 10-fold in iron-enriched bottles but at most 3-fold in control bottles; pennate diatoms accounted for most of the increase in chlorophyll in iron-enriched bottles.
AN: 4040484
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TI: Nitrate and chlorophyll distributions in relation to thermohaline and current structures in the western tropical Pacific during 1985-1989
AU: Radenac,-M.-H.; Rodier,-M.
AF: Groupe FLUPAC, ORSTOM, B.P. A5, Noumea, New Caledonia
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 725-752
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: Fourteen transects carried out from 1985 to 1989 permit us to describe the nitrate and chlorophyll a distributions and their temporal variability in the tropical western Pacific (165 degree E, 20 degree S-10 degree N). Sections representative of the moderate 1986-1987 El Nino, the strong 1988-1989 La Nina and an equatorial westerly wind burst were compared to the January 1986 transect, which we define as a "reference" section. Along 165 degree E, there appears to be four characteristic distributions of nitrate and chlorophyll relative to the thermohaline structure. (1) In the south (20-17 degree S), a seasonal cycle was observed in both nitrate and chlorophyll distributions. Variability of surface chlorophyll and depth of the deep chlorophyll maximum (DCM) was associated with variations in the vertical mixing and available amount of light. (2) In the north (6-10 degree N), seasonal and interannual changes remained in the subsurface layer because of the strong stratification. Ekman pumping is one cause of the changes of the DCM depth. (3) In the 2 degree S-2 degree N band, the seasonal variability of the DCM depth was associated with variations in precipitation and eastward advection of low salinity water. During the 1986-1987 El Nino, elevation and intensification of the pycnocline and shoaling of the nutrient reservoir were the result of basin-wide changes. Consequences included abnormally low surface chlorophyll concentrations and an increase of the primary production. Intra-El Nino variations of the DCM depth were associated with changes of the thickness of the low salinity surface layer. During the subsequent La Nina, upwelling developed and vertical nitrate and chlorophyll distributions were strongly modified. Surface nitrate and chlorophyll concentrations for this period were the highest of the dataset, and primary production values were about twice the El Nino values. The main differences between upwelling in the western and central Pacific are attributed to the existence of two atmospheric convergence zones in the western basin, and especially to the tendency of the Intertropical Convergence Zone to migrate south of the equator. Intraseasonal Kelvin waves influence the variations of nutrient concentration and phytoplankton biomass. During the December 1989 westerly wind burst, there were strong modifications of the thermohaline and nitrate distributions, associated with a geostrophic adjustment, which were not echoed on the chlorophyll distribution. (4) At 10 degree S, a doming of the different properties was frequently observed. Transient surface enrichments in nitrate or chlorophyll result from combined effects of the divergence between the South Equatorial Counter Current and the southern branch of the South Equatorial Current, Ekman pumping favourable to upwelling and local wind events. In all cases, nitrate and chlorophyll distributions were closely linked to the density structure for which salinity can be the controlling factor. Low-frequency variability (seasonal, intraseasonal and interannual scales) of the nitrate and chlorophyll distributions were determined primarily by local or remote physical processes which controlled stability of the water column that governs the vertical displacements of phytoplankton.
AN: 4040483
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TI: Contributions of phytoplankton light scattering and cell concentration changes to diel variations in beam attenuation in the Equatorial Pacific from flow cytometric measurements of pico-, ultra- and nanoplankton
AU: Durand,-M.D.; Olson,-R.J.
AF: Biol. Dep., Woods Hole Oceanographic Inst., Woods Hole, MA 02543-1049, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 891-906
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: The phytoplankton biomass in the equatorial Pacific is dominated by picophytoplankton (Prochlorococcus, <1 mu m, and Synechococcus, similar to 1 mu m diameter) and by mixed populations of ultraphytoplankton (1-2 mu m diameter) and nanophytoplankton (2-20 mu m, mostly 2-3 mu m). The mean forward light scatter of each of these populations, measured on individual cells by flow cytometry, increased during the day and decreased during the night. This pattern was similar to that of bulk red beam attenuation due to particles. In contrast, cell concentration changes did not correspond to the patterns in beam attenuation. Using a combination of empirical calibrations relating beam attenuation to flow cytometric measurements of pure cultures of phytoplankton in the laboratory and Mie theory, we estimated the contributions of different groups of phytoplankton to the diel variations in beam attenuation observed. Our results indicate that the phytoplankton assemblage measured by flow cytometry can account for essentially all of the diel variation in the beam attenuation signal. In most instances nanophytoplankton were the largest contributor to total beam attenuation due to phytoplankton, but ultraphytoplankton usually were more important in determining the diel variations in this property. Prochlorococcus, were a smaller but appreciable contributor to beam attenuation changes, and Synechococcus were much less important.
AN: 4040482
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TI: Dynamics of picophytoplankton, ultraphytoplankton and bacteria in the Central Equatorial Pacific
AU: Binder,-B.J.; Chisholm,-S.W.; Olson,-R.J.; Frankel,-S.L.; Worden,-A.Z.
AF: Dep. Mar. Sci., Univ. Georgia, Athens, GA 30602-2206, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 907-931
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: Pico- and ultraplankton are known to contribute significantly to overall biomass and primary productivity in the "high nutrient-low chlorophyll" waters of the equatorial Pacific. In order to understand the dynamics of this community on ecologically relevant time-scales, we examined the abundance, distribution and cellular characteristics of Prochlorococcus, Synechococcus, eukaryotic ultraphytoplankton and heterotrophic bacteria during two 20-day time-series at 0 degree N, 140 degree W in the spring and fall of 1992 (JGOFS time-series cruises, TS-I and TS-II). Prochlorococcus was numerically dominant among the autotrophic groups considered, with mean cell concentrations in surface waters on the order of 1.4 x 10 super(5) cells ml super(-1). Synechococcus and ultraphytoplankton abundances were 17-30-fold lower than those of Prochlorococcus, and heterotrophic bacterial abundances were 5-7-fold higher (during TS-I and TS-II, respectively). Daily cell abundances for all groups varied by factors of 1.5-2 within each time-series. Depth-integrated Prochlorococcus abundance averaged over each time-series was 25% lower during TS-II relative to TS-I; ultraphytoplankton abundance was 42% higher during the same period. Prochlorococcus and ultraphytoplankton both contributed significantly to the estimated total autotrophic biomass; Synechococcus contributed relatively little. Estimated total photosynthetic pico- plus ultraplankton biomass was on average 30% higher than heterotrophic bacterial biomass. Changes in the fluorescence and light scatter properties of individual Prochlorococcus cells were observed during the passage of a tropical instability wave during TS-II, and are hypothesized to reflect a physiological response among these cells to that event. Examination of bulk properties alone (e.g. cell numbers or total red fluorescence) would not have revealed these physiological changes. Lower bounds for Prochlorococcus-specific growth rates were calculated based on the DNA distributions of these populations at dusk. These rates were maximal at 15 or 30 m depth, where they approached one doubling per day. Changes in Prochlorococcus forward angle light scatter (FALS) from dawn to dusk were well correlated with these estimates of specific growth rate, an observation that allowed us to relate measurements of FALS to cell volume for Prochlorococcus.
AN: 4040475
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TI: Distribution of nitrous oxide and methane in the Arabian Sea
AU: Lal,-S.; Patra,-P.K.; Venkataramani,-S.; Sarin,-M.M.
AF: Physical Research Laboratory, Ahmedabad 380 009, India
SO: CURR.-SCI. 1996 vol. 71, no. 11, pp. 894-899
LA: English
ER: M (Marine)
AB: Measurements of the two important biogenic gases N sub(2)O and CH sub(4) have been made both in the water column and in air of the Arabian Sea during April-May 1994 and February-March 1995, as part of the JGOFS (India) Programme. The average abundances of N sub(2)O and CH sub(4) in the air are 313 plus or minus 7 ppbv and 1.69 plus or minus 0.05 ppmv respectively. During both the periods, the vertical profiles of N sub(2)O in the water column show a double peak structure with the dominant peak in the 500-1000 m depth region with concentrations of 70-80 nmol. The entire water column is supersaturated with respect to N sub(2)O and in the major peak region it is supersaturated by as much as 600-800%, suggesting this region of the Arabian Sea to be an important reservoir of N sub(2)O. During February-March 1995, sea-air flux of N sub(2)O is calculated to be about 0.26 pg cm super(-2)s super(-1), while the flux calculated for April-May 1994 is not significantly different from zero. Methane concentrations were measured only down to 400 m depth. Its distribution shows a peak concentration of 6-8 nmol in the 100-200 m depth region. Supersaturation (up to 200-400% at the peak) is found for CH sub(4) in most of the profiles. Average sea-air flux of methane during April-May 1994 February-March 1995 is 0.0001 and 0.033 pg cm super(-2)s super(-1), respectively.
AN: 4034488
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TI: super(234)Th scavenging and particle export fluxes from the upper 100 m of the Arabian Sea
AU: Sarin,-M.M.; Rengarajan,-R.; Ramaswamy,-V.
AF: Physical Research Laboratory, Ahmedabad 380 009, India
SO: CURR.-SCI. 1996 vol. 71, no. 11, pp. 888-893
LA: English
ER: M (Marine)
AB: We have determined the particle scavenging rates, export fluxes of super(234)Th and settling particles from the upper 100 m of the Arabian Sea as a part of the JGOFS (India) Programme. The spatial and temporal measurements made in the open ocean profiles reveal close similarities in the dissolved super(234)Th: super(238)U disequilibria, suggesting that the rates of particle-associated scavenging processes are generally uniform in the central Arabian Sea. The observed disequilibrium integrated for the upper 100 m yields a mean scavenging residence time of mu 30 days and a removal rate of mu 3400 dpm m super(-2) d super(-1) for super(234)Th, from dissolved to particulate phases. The deficiency of total super(234)Th (dissolved + particulate) relative to super(238)U allows us to compute the vertical export flux of particulate super(234)Th. The flux data for the upper 100 m show spatial variations with enhanced export fluxes centered around 22 degree N 67 degree E, a region characterized by higher rates of column primary productivity. Using the super(234)Th export fluxes and the measured specific activity of super(234)Th in the sediment traps, we have computed th eparticle and carbon fluxes at 100 m. These results reveal that the particle fluxes determined from sediment traps are systematically low and the estimated C export fluxes are grossly out of proportion with the column primary production.
AN: 4034487
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TI: Seasonal variations in inorganic carbon components in the central and eastern Arabian Sea
AU: Sarma,-V.V.S.S.; Dileepkumar,-M.; George,-M.D.; Rajendran,-A.
AF: NIO, Dona Paula, Goa 403 004, India
SO: CURR.-SCI. 1996 vol. 71, no. 11, pp. 852-856
LA: English
ER: M (Marine)
AB: Extensive observations have been made on the carbon dioxide system in the Arabian Sea during three different seasons as part of the Indian Joint Global Ocean Flux Study (JGOFS) Programme. Concentrations of total carbon dioxide and partial pressure of carbon dioxide exhibited seasonal variability, with pronounced north-south gradients in surface layers. Total carbon dioxide in surface waters was higher by similar to 100 mu M during winter compared to the intermonsoon period due to winter cooling and convective mixing. The partial pressure of carbon dioxide (pCO sub(2)) in surface layers was generally in excess over the atmospheriec value, suggesting that the central and eastern Arabian Sea is a perennial source to atmospheric carbon dioxide. The flux of carbon dioxide to atmosphere reached a maximum of similar to 40 m mole m super(-2)d super(-1) around 16 degree N in the central Arabian SEa during monsoon season. The carbon dioxide regenerated from soft tissue was higher during winter and is the least in monsoon. The aragonite saturation horizon occurred around 500 m.
AN: 4034480
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TI: Seasonal variability in oxygen and nutrients in the central and eastern Arabian Sea
AU: Desousa,-S.N.; Dileepkumar,-M.; Sardessai,-S.; Sarma,-V.V.S.S.; Shirodkar,-P.V.
AF: NIO, Dona Paula, Goa 403 004, India
SO: CURR.-SCI. 1996 vol. 71, no. 11, pp. 847-851
LA: English
ER: M (Marine)
AB: Extensive observations made in the central and eastern Arabian Sea under JGOFS (India) programme suggest strong seasonal variations in concentrations of oxygen and nutrients in the water column. In the intermediate waters (depth range 150-800 m) oxygen concentrations were lowest during winter (with values near zero at similar to 400 m) in relation to those in the other two seasons (intermonsoon and southwest monsoon). This together with nitrate distributions revealed the occurrence of intense reducing conditions in intermediate waters during winter because of the sluggish water movement and high surface productivity. Secondary nitrite, an indicator of occurrence of denitrification was present at oxygen levels < 10 mu M. Nitrate deficits reached a maximum of 10 mu M in winter, whereas, it was half this value in monsoon. The average deficits suggest increasing reducing conditions in the order monsoon (1.6 mu M), intermonsoon (3.7 mu M) and winter (4.0 mu M).
AN: 4034479
63 of 71
TI: Arabian Sea upwelling -- a comparison between coastal and open ocean regions
AU: Muraleedharan,-P.M.
AF: NIO, Dona Paula, Goa 403 004, India
SO: CURR.-SCI. 1996 vol. 71, no. 11, pp. 842-846
LA: English
ER: M (Marine)
AB: The response of the eastern Arabian Sea to prevailing winds during an upwelling event, in the peak of southwest monsoon, was studied at both coastal and open ocean environment based on the data collected as a part of the Indian Joint Global Ocean Flux Studies (JGOFS) programme. Analysis of wind measurements indicated active upwelling along the southwest coast of India, which gradually propagates towards north. While the dominant long-shore component of the wind induces upwelling in the south, the cross-shore component is instrumental in modifying the density structure of the surface layer, especially in the north, to produce retarding effect. In open ocean, the wind maximum around 17 degree N and 64 degree E indicates the axis of the Findlater Jet. The observed surfacing and deepening of the isotherms on either side of the axis are the signatures of the upwelling and sinking associated with the Findlater Jet.
AN: 4034478
64 of 71
TI: Measured and modeled primary production in the Northeast Atlantic (EUMELI JGOFS program): The impact of natural variations in photosynthetic parameters on model predictive skill
AU: Morel,-A.; Antoine,-D.; Babin,-M.; Dandonneau,-Y.
AF: Lab. de Physique et Chimie Marines, Univ. Pierre et Marie Curie and CNRS, BP 8, F-06230 Villefranche-sur-Mer, France
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1996 vol. 43, no. 8, pp. 1273-1304
LA: English
ER: M (Marine)
AB: Use of ocean color satellite data in global biogeochemical studies requires models to predict primary production from the satellite-derived chlorophyll fields. In this paper, measured bio-optical and photo-physiological data are used in place of standard (constant) parameters to adjust a previously published primary production model. In the JGOFS-France program, systematic studies were carried out at three locations in the tropical northeast Atlantic, selected to represent typical EUtrophic, MEsotrophic and oLIgotrophic regimes (EUMELI cruises). During cruise no. 4, these studies included the spectral measurements of the photosynthetically available radiation at sea level and within the water column, the determination of the algal absorption spectra and the determination of the physiological parameters derivable from P versus E experiments (photosynthesis-irradiance responses). The model predictions are compared with in situ determinations made by the super(14)C technique (JGOFS core parameter). At the three sites, the physical structure (mixed layer and euphotic depths), the algal abundance and community structure, as well as their bio-optical and physiological properties, are very different, so that the predictive performance of the model was tested in trophic conditions that span most of those expected in the global open ocean. The model, when adjusted by entering the actual physiological parameters (chlorophyll-specific absorption of algae, maximum quantum yield, and light saturated carbon fixation rate), provides satisfying results compared to those observed in situ. The relative roles of the physiological parameters are analyzed and sensitivity studies are performed. For global applications, and in the absence of specific information when all seasons and provinces of the world ocean are considered, it will remain necessary for a while to rely on generic models and a selected standard set of physiological properties. The sensitivity studies here presented help in this choice, and a modified set of parameters is proposed and tested. With this set, reconstructed production profiles are close to those determined in the field, and the integrated values are retrieved with no bias and a reduced scatter (18% at one SD) for 17 stations (cruises 3 and 4) and daily production ranging from 0.3 to 2.3 gC m super(-2).
AN: 4029371
65 of 71
TI: Daily, seasonal and interannual variability of sea-surface carbon and nutrient concentration in the equatorial Pacific Ocean
AU: Archer,-D.E.; Takahashi,-T.; Sutherland,-S.; Goddard,-J.; Chipman,-D.; Rodgers,-K.; Ogura,-H.
AF: Dep. Geophysical Sci., Univ. Chicago, Chicago, IL 60637, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 779-808
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: We present measurements of the partial pressure of CO sub(2) in seawater (pCO sub(2)), total dissolved inorganic carbon concentration ( capital sigma CO sub(2)) and alkalinity made during the JGOFS Survey I (TT007, February-March 1992) and Survey II (TT011, August-September 1992) expeditions. JGOFS data are compared with data from the Hawaii-Tahiti Shuttle Experiment (HTSE, February 1979-June 1980). The Survey I and II expeditions took place during and after the El Nino event of 1992, while HTSE occurred during mild El Nino to near-climatological conditions. The Survey I and II sea-surface temperatures (SSTs) are among the warmest and coldest, respectively, in the combined JGOFS and HTSE dataset, and sea-surface concentrations of the biological tracers, NO sub(3) and pCO sub(2), from JGOFS bracketed the HTSE data with lower concentrations during Survey I and higher values during Survey II. However, the air-sea contrast in pCO sub(2) was diminished in 1992 due to rising atmospheric values. The variability of sea-surface concentrations of biological tracers seems to be controlled primarily by the physical structure of the water column. In a comparison of HTSE and JGOFS data (decadal timescale), or Survey I and II data (seasonal/ENSO timescale), the concentrations of the tracers on constant-density (isopycnal) surfaces is nearly time invariant, so that the variation in sea-surface concentrations is controlled by the outcropping of isopycnal surfaces. On the timescale of the station occupation (diurnal to a few days), variation in replicate measurements of pCO sub(2) is correlated with variation in density, again indicating physical rather than biological control of pCO sub(2) variability. These findings make an interesting contrast to JGOFS North Atlantic Bloom Experiment results, where recent local biological forcing was found to dominate chemical variability. The implication of this finding is that a physical understanding of the equatorial Pacific circulation may be sufficient to make predictions of short-term variability in air-sea pCO sub(2) fluxes in this region. Some minor exceptions to the rule of physical control of sea-surface chemical properties include a freshwater cap just south of the equator that follows the sea surface, rather than any density surface, and Si, which appears to vary seasonally independently of the other biological tracers NO sub(3), CO sub(2), and O sub(2). Based on the relationship between the alkalinity and capital sigma CO sub(2) in the upper 400 m of the water column, about 13% of the capital sigma CO sub(2) increase with depth is due to the dissolution of CaCO sub(3), 65% to the oxidation of biogenic debris and 23% to the increasing solubility of CO sub(2) in colder waters. The relationship between capital sigma CO sub(2) and O sub(2) in equatorial surface waters during Survey II indicates a vigorous circulation with an overturning timescale of only a few days.
AN: 4028376
66 of 71
TI: Bicapitate Nitzschia species: Abundant nanoplankton in aggregates during November-December (1992) in the Equatorial Pacific
AU: Lee,-Hak-Young; Fryxell,-G.A.
AF: Dep. Oceanogr., Texas A&M Univ., College Station, TX 77843-3146, USA
SO: J.-PLANKTON-RES. 1996 vol. 18, no. 8, pp. 1271-1294
LA: English
ER: M (Marine)
AB: From 12 degree S to 9 degree N similar to 140 degree W on the benthic cruise of the US Joint Global Ocean Flux Studies (JGOFS), horizontal near-surface net tows (n = 18) and vertical net hauls (n = 15, 200-0 m) yielded high relative abundances of small, bicapitate, intact Nitzschia valves (average 59.0 and 56.0% of total diatoms, respectively), although >90% of them were too small to have been caught effectively with the net used. This complex was much less common (average 3.2% of diatoms) in the surface sediment samples (n = 7, 12 degree S-9 degree N, below water depths of 4269-4991 m). Examination under the light microscope showed concentrations of cells associated with organic detritus, planar and cylindrical membranous structures, fecal pellets, and occasionally on other diatoms (e.g. Asterolampra), i.e. on or within particles large enough to be collected in the net. Although Nitzschia bicapitata Cleve has been considered to have a characteristic range of shapes, and has often been cited from open-ocean habitats in nano- and microplanktonic studies, a scanning electron microscopic study revealed several species in our material. Examples of larger and smaller species are given, and Nitzschia ikeanae G.Fryx. & H.Lee, sp. nov., is described here. Ecologically, these observations indicate that although some are grazed and have been seen aggregated in fecal pellets, these small pennate diatoms can affix to and grow on substrates, termed 'pseudo-benthic habitats' in the open ocean, resulting in unexpected concentrations that have implications for their life histories and sexual cycles, selection or avoidance by grazers, sinking on substrates, and roles in the recycling of nutrients in near-surface waters.
AN: 4015072
67 of 71
TI: A rosette system for the collection of trace metal clean seawater
AU: Hunter,-C.N.; Gordon,-R.M.; Fitzwater,-S.E.; Coale,-K.H.
AF: Moss Landing Mar. Lab. (MLML), P.O.B. 450, Moss Landing, CA 95039, USA
SO: LIMNOL.-OCEANOGR. 1996 vol. 41, no. 6, pp. 1367-1372
LA: English
ER: M (Marine)
AB: We designed a large-volume rosette sampler for collecting seawater with minimal trace metal contamination. The system uses eight modified 30-liter Go-Flo bottles secured to a Nylon II-coated stainless steel frame. The instrument is deployed with a dedicated winch with polyurethane-coated, three-conductor Kevlar hydroline. A prototype was used as part of the U.S. JGOFS Equatorial Pacific sampling program during spring and fall 1992. A redesigned model was used during the 1993 IronEx experiments and is currently being deployed in the Arabian Sea. The results of trace metal analyses collected on these cruises indicate that samples recovered are comparable to current single Go-Flo casts.
AN: 4012006
68 of 71
TI: A convergent instability wave front in the central Tropical Pacific
AU: Johnson,-E.S.
AF: Joint Inst. for Study Atmos. and Oceans, Box 354235, Univ. Washington, Seattle, WA 98195-4235, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 753-778
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: A narrow front encountered at 2.1 degree N, 140 degree W was characterized by high productivity and a 2 degree C temperature drop. Satellite sea-surface temperature (SST) imagery showed this front to extend over 400 km from just north of the equator to 5 degree N along the western (leading) edge of a tropical instability wave cold cusp. During 3 days of observations the front propagated westward at 64 cm s super(-1) while oriented SW-NE. Water velocities and densities around the front were measured using a shipboard acoustic Doppler current profiler and hydrographic stations. These data showed warm, fresh northern water moving southward at speeds of up to 50 cm s super(-1) to encounter cold, salty equatorial water moving northward at up to 40 cm s super(-1); both slabs were embedded in the South Equatorial Current, here a uniform 100 m deep westward flow of 90 cm s super(-1). At their meeting a net convergence of 30 cm s super(-1) across the 1-km wide front drove intense downwelling of up to 0.9 cm s super(-1). Both T-S relations and velocity fields indicate that cold water subducted beneath the warmer water and continued northward to beyond 3 degree N, deepening to 120 m. For analysis the data were gridded in a co-ordinate system centered on the front and moving with it. The dynamics near the front consisted of a balance between pressure gradient and non-linear advection; the Coriolis force was smaller and associated mostly with the broader scale flow. Thus, the front itself was not geostrophic, but rather the leading edge of a density-driven flow that can be accurately modeled as a dissipative lock-exchange. The subduction released potential energy at the rate of 5290 plus or minus 230 W m super(-1) of front length, comparable to previous estimates of large-scale energy conversion. Nevertheless, the kinetic energy gain by the larger-scale instability was only 840 plus or minus 31 W m super(-1), implying that the rest of the energy was lost to the large-scale flow. Turbulent dissipation as derived from the rate of mixing accounted for only 500 plus or minus 300 W m super(-1) of this loss. On the full 100 km-scale of the layered flow, the Coriolis force became important: the orientation of the surface front and the angle of the interface's northward deepening produced a pressure gradient that balanced the meridional flow geostrophically.
AN: 4006286
69 of 71
TI: Mixed layer circulation during EqPac and some thermochemical implications for the equatorial cold tongue
AU: Hansen,-D.V.; Swenson,-M.S.
AF: Cooperative Inst. for Mar. and Atmos. Stud., Univ. Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 707-724
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: Surface currents inferred from satellite-tracked drifting buoys were used to develop a chronology of surface currents in the Central Pacific for the year encompassing the EqPac field program. Salient features of the chronology are the early months of the program witnessed anomalous eastward current surges near the equator within the moderate El Nino event, followed by a period of anomalously strong westward flow near the equator and eastward flow in the North Equatorial Countercurrent that led, in mid-summer, to an eruption of tropical instability waves that continued until the end of the field program. None of these events was particularly unusual, but they were departures from climatology that influence the interpretation of the biochemical measurements made for EqPac. Results from a semi-quantitative conceptual model indicate that tropical instability waves have more important long-term, as well as short-term, consequences for thermochemical properties of the cold tongue than previously recognized.
AN: 4006285
70 of 71
TI: Vertical velocity in the central Tropical Pacific: A circulation model perspective for JGOFS
AU: Harrison,-D.E.
AF: Pacific Mar. Environ. Lab., NOAA, 7600 Sand Point Way NE, Seattle, WA 98115, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 4-6, pp. 687-705
NT: Special issue: A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2.
LA: English
ER: M (Marine)
AB: Results from a variety of experiments with a primitive equation ocean general circulation model are examined to provide insight about variations in vertical velocity (W) that may have occurred during the JGOFS Equatorial Pacific field program. Measurements of W during this period are not available, so a model offers the only plausible, dynamically consistent way to obtain this information. Variability associated with four different aspects of the tropical Pacific circulation is discussed: the seasonal average; the tropical instability waves (TIW); the interannual variability in strong and modest ENSO events; and the Kelvin response associated with remote forcing from westerly wind events in the western Pacific. Results from 140 degree W are presented. According to the model, TIW provide the greatest source of W variability. Near and somewhat north of the equator W can range from about 1500 cm day super(-1) upward to 1000 cm day super(-1) downward over a typical 30-day period, with significant structure in both the zonal and meridional directions. Remotely forced response can be very large on the day-to-day timescale, but diminishes typically to, at most, a few hundred cm day super(-1) up or down when averaged over 10 days. Interannual variation associated with a major ENSO event can involve complete disruption of the seasonal cycle, the disappearance of TIWs and great diminution or disappearance of the normal equatorial upwelling. The seasonal cycle variations are of the smallest amplitude; the maximum variation is perhaps 100 cm day super(-1) near the equator and somewhat more just north of the equatorial waveguide in the downwelling part of the seasonal circulation. The field program period was studied using the different available wind analyses to force the model over the 1991-1992 period. Because the wind analyses have substantial differences, they force substantially different W fields in the ocean model. Unfortunately, no wind analysis can be shown to be substantially superior to any other during this period. Thus, estimates of the net vertical transport of any quantity of JGOFS interest must take into account the wide range of possible W values.
AN: 4006284
71 of 71
TI: Gas supersaturation in the surface ocean: The roles of heat flux, gas exchange, and bubbles
AU: Schudlich,-R.; Emerson,-S.
AF: Sch. Oceanogr., Univ. Washington, Box 357940, Seattle, WA 98195-7940, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 2-3, pp. 569-589
NT: Special issue: Ocean time-series: Results from the Hawaii and Bermuda research programs.
LA: English
AB: In this paper, a one-dimensional model of mixed layer dynamics is used to examine the roles of heat flux, gas exchange, and bubble processes in producing nitrogen and argon gas supersaturation in the surface subtropical Pacific ocean at U.S. JGOFS Station ALOHA during 1989-1990. The N sub(2)/Ar ratio is measured within a high degree of accuracy by mass spectrometry, and the ratio is sensitive to the mode of bubble gas transfer. Our results demonstrate that bubble processes are essential to produce observed supersaturation levels. N sub(2)/Ar ratios at Station ALOHA indicate that air injection of small (totally-dissolving) bubbles is the dominant process during the summer, but during the fall and winter, larger (partially-dissolving) bubbles become more important. Given current measurement techniques, it is possible to distinguish between small and large bubbles when inert gas supersaturations are high (> 2%) and when the dynamic range in predicted inert gas ratios is largest (late fall). Existing models that parameterize bubble dynamics as a function of wind speed do not reproduce the high observed supersaturations that this study indicates are influenced by large bubble processes.
AN: 3976506
No. Records Request
1: 71 JGOFS
Searches and records above from: ASFA 1997-1998/09
3: 200 #1
4: 14252 INDIA
5: 1 #3 and INDIA
6: 200 #3
1 of 200
TI: [BIO-C-FLUX. Biological carbon flux in near bottom water of the open ocean. Final report for the support period 1.1.1990-31.12.1994.]
OT: BIO-C-FLUX. Biologischer Kohlenstofffluss in der bodennahen Wasserschicht des kuestenfernen Ozeans. Schlussbericht fuer den Foerderzeitraum 1.1.1990-31.12.1994
AU: Pfannkuche,-O.; Hoppe,-H.-G.; Thiel,-H.; Weikert,-H.-(eds.)
SO: BER.-INST.-MEERESKD.-CHRISTIAN-ALBRECHTS-UNIV.-KIEL 1995 no. 280, 114 pp.
NT: Research project funded by the Bundesministerium fuer Forschung und Technologie - Grant numbers: 03F0565A/03F0566A & 03F0094A/03F0094B. Bibliogr.: 28 ref.
LA: German
ER: M (Marine)
AB: This report presents the results of biological investigations in the near-bottom water layer in the deep sea of the Northeast Atlantic. The project BIO-C-FLUX was carried out by the Institut fuer Hydrobiologie und Fischereiwissenschaft der Universitaet Hamburg, Arbeitsgruppe Biologische Ozeanographie, and by the Institut fuer Meereskunde an der Universitaet Kiel, Abteilung Marine Mikrobiologie. The investigations were funded by the Bundesministerium fuer Forschung und Technologie, grants 03F0565A/03F0566A (1.1.90-31.12.92) and 03F0094A/03F0094B (1.1.93-31.12.94). The scientific framework of BIO-C-FLUX is closely associated with the international JGOFS (Joint Global Ocean Flux Study) program which deals, on a global scale, with the biological aspects of the marine carbon cycle, concentrating mainly on the carbon flux in the upper mixed layer of the open ocean. BIO-C-FLUX, on the other hand, focused on the study of the organic carbon flux in the benthic boundary layer of the offshore deep sea, including the near-bottom water layer up to 500 m above bottom (mab), the sediment contact water (up to 20 cm above bottom), the sediment surface and the sediment layers down to 50 cm depth. In collaboration with the MAST II project OMEX (Ocean Margin Exchange), the investigations could be extended in 1993/94 to cover gradients from the continental shelf to the deep-sea basins. BIO-C-FLUX studied the following main topics: - the biological turnover of sedimented POC by the benthopelagic and benthic faunas. The benthopelagic fauna included bacteria, zooplankton, nekton, and megafauna. The benthic studies covered bacteria, nano-, meio- and macrofauna. - the quantity and quality of sedimented POC. - the temporal and spatial variability of composition, standing stocks and turnover of POC in various faunal groups within the subsystems (benthopelagos, benthos) studied.
AN: 3967803
2 of 200
TI: Chronic substrate limitation of silicic acid uptake rates in the western Sargasso Sea
AU: Brzezinski,-M.A.; Nelson,-D.M.
AF: Dep. Ecol., Evolution and Mar. Biol., Univ. California, Santa Barbara, CA 93106, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 2-3, pp. 437-453
NT: Special issue: Ocean time-series: Results from the Hawaii and Bermuda research programs.
LA: English
ER: M (Marine)
AB: The kinetics of Si uptake at the JGOFS Bermuda Atlantic Time-series Study (BATS) Site in the western Sargasso Sea (31 degree 50'N, 64 degree 10'W) were examined on nine cruises between November 1991 and November 1993. Si uptake rates were severely substrate-limited on every cruise during all seasons. Surprisingly, the observed uptake kinetics were among the most inefficient examined to date despite persistently low (<0.9 mu M) ambient silicic acid concentrations ([Si(OH) sub(4)]) throughout the upper 100 m. Uptake kinetics did not usually conform to the Michaelis-Menten function. Rather, rates increased approximately linearly with increasing substrate concentration to ca 5.5 mu M, the highest concentration tested, on seven of the nine cruises. Half saturation constants on the remaining two cruises when some degree of hyperbolic response to increasing [Si(OH) sub(4)] was observed were 1.6 plus or minus 0.55 and 2.6 plus or minus 1.5 mu M (s.e.). The slopes of the linear kinetic curves ranged from 1.5 x 10 super(-3) to 8.3 x 10 super(-3) h super(-1) mu M super(-1) with no clear seasonal trend. Ambient [Si(OH) sub(4)] restricted in situ uptake rates to <12-16% of those measured at the highest concentration employed, ca 5.5 mu M. These results indicate that substrate limitation of Si uptake is both chronic and severe in this region of the Sargasso Sea. The observed severity of uptake rate limitation strongly suggests Si limitation of diatom growth rates. Comparison of estimated in situ Si uptake rates with silica dissolution rates within sediment traps deployed at the base of the euphotic zone suggest that diatom assemblages with the observed uptake kinetics would require [Si(OH) sub(4)] greater than ca 0.6 mu M to support Si uptake rates sufficient to balance losses due to dissolution. This may explain why Si(OH) sub(4) is never depleted to the nanomolar concentrations observed for NO sub(3) super(-) and HPO sub(4) super(2-) at this site. However, essentially all Si(OH) sub(4) in excess of the threshold concentration of ca 0.6 mu M is utilized by diatoms, suggesting that Si limits the yield of siliceous biomass. Limitation of the yield of diatoms by Si is consistent with the estimated mole ratio of N:Si:P supplied annually to the base of the surface layer from depth. That ratio, 20:5.2:1, demonstrates a clear deficit of Si(OH) sub(4) in the upward flux of those nutrients compared Redfield proportions.
AN: 3965260
3 of 200
TI: Seasonal and interannual variations in photosynthetic carbon assimilation at Station ALOHA
AU: Letelier,-R.M.; Dore,-J.E.; Winn,-C.D.; Karl,-D.M.
AF: Coll. Oceanic and Atmos. Sci., Oregon State Univ., Ocean. Admin. Bldg. 104, Corvallis, OR 97331-5503, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 2-3, pp. 467-490
NT: Special issue: Ocean time-series: Results from the Hawaii and Bermuda research programs.
LA: English
ER: M (Marine)
AB: Autotrophic carbon assimilation measurements using a trace metal-free super(14)C technique were performed at near monthly intervals between 1988 and 1992 in the North Pacific Subtropical Gyre (U.S. JGOFS-WOCE Sta. ALOHA; 22 degree 45'N, 158 degree 00'W). Integrated photosynthetic values ranged from 127 to 1055 mg C/m super(2)/day while the average carbon assimilation number (P super(B)), defined as carbon assimilation rate per unit chlorophyll a (chl a), varied between 1.6 and 12 g C/(g chl a) h in the 0-45 m depth range. Consistently low P super(B) values (< 5 g C/(g chl a) h, averaged in the upper 45 m of the water column) were observed during the first 2 years of this study but increased to >5 g C/(g chl a) /h during 1991-1992. This rise in P super(B) was not associated with an increase in chl a. Furthermore, it occurred during a period of increased water column stability. Reduction in ATP and (NO sub(3) super(-) + NO sub(2) super(-)) concentrations in the upper euphotic zone suggests that nutrient injections due to mixing events were minor or absent after January 1991. Two non-exclusive hypotheses are presented to explain the rise of P super(B) in the absence of an enhancement of inorganic nutrient fluxes from below the euphotic zone: (i) high P super(B) values observed during 1991-1992 are indicative of phytoplankton growth being balanced as a result of a decrease in the variability of nutrient injection due to a reduction in the frequency of mixing events, and (ii) the rise of P super(B) during 1991-1992 is caused by an ecosystem shift from nitrogen to phosphorus limitation. The stability of the water column during 1991-1992 may have increased the availability of reduced nitrogen relative to phosphorus due to the enhancement of nitrogen fixation. Because these hypotheses do not require an increase in algal biomass or elemental fluxes across the base of the euphotic zone to explain an increase in autotrophic carbon assimilation, they imply that nutrient dynamics within the euphotic zone of the North Pacific subtropical gyre need to be understood in order to interpret changes in P super(B) and predict carbon fluxes.
AN: 3965259
4 of 200
TI: A new coupled, one-dimensional biological-physical model for the upper ocean: Applications to the JGOFS Bermuda Atlantic Time-series Study (BATS) site
AU: Doney,-S.C.; Glover,-D.M.; Najjar,-R.G.
AF: Climate and Global Dynamics, Natl. Cent. for Atmos. Res., Boulder, CO 80307, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 2-3, pp. 591-624
NT: Special issue: Ocean time-series: Results from the Hawaii and Bermuda research programs.
LA: English
ER: M (Marine)
AB: This paper presents a new coupled, one dimensional biological-physical model applied to the subtropical region near Bermuda. The physical component of the model, which is driven by smooth climatological forcing, successfully reproduces the long-term seasonal cycles of upper ocean temperature, salinity and boundary layer depth from Hydrostation S. The nitrogen-based biological model, which includes the effects of photoadaptation, phytoplankton aggregation, and particle remineralization in the aphotic zone, shows significant skill in capturing the major features of the annual chlorophyll field (e.g. spring bloom, deep chlorophyll maximum) and depth-integrated chlorophyll and primary production as exhibited by the U.S. JGOFS Bermuda Atlantic Time-series Study (BATS) data. The introduction of variable phytoplankton chlorophyll-to-nitrogen ratios is found to be important for simulating the subsurface chlorophyll maximum, and the model solutions show a realistic deep nitracline in the summer and a low annual average f-ratio of similar to 0.21 compared to previous modeling work. The performance of the model solutions are weakest during the late summer, when the model can not supply enough nutrients to support the high production observed in the stratified near-surface waters. The coupled model has large winter production values, leading to a substantial export of organic material from the euphotic zone via downward turbulent mixing. The model predicts a total export production from the euphotic zone of 0.24 mol N/m super(2)/year, approximately equally partitioned between particle sinking and suspended matter detrainment. The bulk of the export production is remineralized in the shallow aphotic zone, and only a small fraction is transported below the depth of the maximum winter mixed layer and thus contributes to "biological pump".
AN: 3965258
5 of 200
TI: Stocks and dynamics of bacterioplankton in the northwestern Sargasso Sea
AU: Carlson,-C.A.; Ducklow,-H.W.; Sleeter,-T.D.
AF: Bermuda Biol. Stn. for Res., Ferry Reach GE 01, Bermuda
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 2-3, pp. 491-515
NT: Special issue: Ocean time-series: Results from the Hawaii and Bermuda research programs.
LA: English
ER: M (Marine)
AB: We examined seasonal variations of bacterioplankton stocks and distributions in the upper 250 m in the Sargasso Sea near Hydrostation S and the U.S. JGOFS Bermuda Atlantic Time-series Study (BATS) site during 1987-1988 and 1991-1994. Mean vertical profiles of bacterial abundance, cell volume, and super(3)H-thymidine and super(3)H-leucine incorporation rates varied seasonally, and distribution patterns were correlated with physical mixing in the fall and winter. Conversion factors for super(3)H-thymidine and super(3)H-leucine incorporation were determined empirically to be 1.63 and 0.078 x 10 super(18) cells mol super(-1), respectively. Integrated bacterial biomass and production within the euphotic zone were low compared to other oceanic sites and ranged between 241-411 mg C m super(-2) and 11-36 mg C m super(-2) day super(-1), respectively. Seasonal variation in bacterial biomass and production was observed; however, the range of variation was less than two-fold despite a five-fold range in primary production. Bacterial biomass (BB): phytoplankton biomass (PB) ratios remained high during the summer and fall, with bacterial biomass dominating the chl a-C estimates at times, and BB:PB ratios decreased in the winter and spring due to increased phytoplankton production. Low bacterial production (BP):phytoplankton production (PP) ratios were observed for all seasons. Although BP:PP ratios were low, growth efficiencies observed in this region indicate that carbon flux through seasonal BP could account for 17- > 100% of seasonal PP. The small response of bacterial production during and after a phytoplankton bloom may indicate that the majority of dissolved organic carbon (DOC) that accumulates in post bloom conditions is of semi-labile quality, resulting in slow bacterial oxidation of DOC.
AN: 3965257
6 of 200
TI: Seasonal and interannual variability of oceanic carbon dioxide species at the U.S. JGOFS Bermuda Atlantic Time-series Study (BATS) site
AU: Bates,-N.R.; Michaels,-A.F.; Knap,-A.H.
AF: Bermuda Biol. Stn. for Res., 17 Biological Stn. Lane, Ferry Reach GE01, Bermuda
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 2-3, pp. 347-384
NT: Special issue: Ocean time-series: Results from the Hawaii and Bermuda research programs.
LA: English
ER: M (Marine)
AB: The seasonal and interannual dynamics of the oceanic carbon cycle and the strength of air-sea exchange of carbon dioxide are poorly known in the North Atlantic subtropical gyre. Between October 1988 and December 1993, a time series of oceanic measurements of total carbon dioxide (TCO sub(2)), alkalinity (TA) and calculated pCO sub(2) was obtained at the Bermuda Atlantic Time-series Study (BATS) site (31 degree 50'N, 64 degree 10'W) in the Sargasso Sea. These measurements constitute the most extensive set of CO sub(2) species data collected in the oligotrophic North Atlantic. Seasonal changes in surface and water-column CO sub(2) species were similar to 40-50 mu mol kg super(-1) in TCO sub(2), similar to 20 mu mol kg super(-1) in TA, and similar to 90-100 mu atm in calculated pCO sub(2). These large changes were driven principally by deep convective winter mixing, temperature forcing and biological activity. TA was well correlated with salinity (with the exception of a 15-25 mu mol kg super(-1) drawdown of TA on one cruise resulting from open-ocean calcification). TCO sub(2) and pCO sub(2) were well correlated with seasonal temperature changes (8-9 degree C). Other underlying processes, such as biological production, advection, gas exchange of CO sub(2) and vertical entrainment, were important modulators of the carbon cycle, and their importance varied seasonally. Each spring-to-summer, despite the absence of measurable nutrients in the euphotic zone, a 35-40 mu mol kg super(-1) decrease in TCO sub(2) was attributed primarily to the biological uptake of TCO sub(2) (evaporation/precipitation balance, gas exchange, and advection were also important). An increase in TCO sub(2) during the fall months was associated primarily with entrainment of higher TCO sub(2) subsurface waters. These seasonal patterns require a reassessment of the modelling of the carbon cycle using nutrient tracers and Redfield stoichiometries. Overall, the region is a weak sink (0.22-0.83 mol C m super(-2) year super(-1)) for atmospheric CO sub(2). Upper ocean TCO sub(2) levels increased between 1988 and 1993, at a rate of similar to 1.7 mu mol kg super(-1) year super(-1). This increase appears to be in response to the uptake of atmospheric CO sub(2) through gas exchange or natural variability of the subtropical gyre.
AN: 3953226
7 of 200
TI: Nitrite distributions and dynamics at Station ALOHA
AU: Dore,-J.E.; Karl,-D.M.
AF: Dep. Oceanogr., Sch. Ocean and Earth Sci. and Technol., Univ. Hawaii, Honolulu, HI 96822, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 2-3, pp. 385-402
NT: Special issue: Ocean time-series: Results from the Hawaii and Bermuda research programs.
LA: English
ER: M (Marine)
AB: We used a chemiluminescence method to measure nitrite concentrations in the water column at the U.S. JGOFS/WOCE time-series station, ALOHA (22 degree 45'N, 158 degree W), from September 1989 to November 1993. We present a detailed time-series of nitrite in the upper 200 m in order to examine the dynamics of the primary nitrite maximum. Our results reveal a double-peaked structure to this feature that is consistent with a vertical separation of the reductive and oxidative microbial processes responsible for nitrite production. The possibility of using the nitrite content of this upper layer as an indicator of nitrogen export from the euphotic zone is explored and rejected. Midwater nitrite profiles (200-1000 m) show a supra-exponential decrease in concentration with depth and reveal month-to-month variability. Nitrite concentrations in deep waters (1000-4800 m) are in the nanomolar-subnanomolar range, and are similar to Atlantic data, arguing against significant basin-scale differences in the deep nitrite pool. Deep profiles also show measurable variability on both monthly and annual timescales. We speculate that this deep variability may be associated with nitrate reduction by sinking phytoplankton cells.
AN: 3953225
8 of 200
TI: The Hawaii Ocean Time-series (HOT) Program: Background, rationale and field implementation
AU: Karl,-D.M.; Lukas,-R.
AF: Dep. Oceanogr., Sch. Ocean and Earth Sci. and Technol., Univ. Hawaii, Honolulu, HI 96822, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 2-3, pp. 129-156
NT: Special issue: Ocean time-series: Results from the Hawaii and Bermuda research programs.
LA: English
ER: M (Marine)
AB: Long-term ocean observations are needed to gain a comprehensive understanding of natural habitat variability as well as global environmental change that might arise from human activities. In 1988, a multidisciplinary deep-water oceanographic station was established at a site north of Oahu, Hawaii, with the intent of establishing a long-term (>20 years) data base on oceanic variability. The primary objective of the Hawaii Ocean Time-series (HOT) program is to obtain high-quality time-series measurements of selected oceanographic properties, including: water mass structure, dynamic height, currents, dissolved and particulate chemical constituents, biological processes and particulate matter fluxes. These data will be used, in part, to help achieve the goals of the World Ocean Circulation Experiment (WOCE) and the Joint Global Ocean Flux Study (JGOFS) research programs. More importantly, these data sets will be used to improve our description and understanding of ocean circulation and ocean climatology, to elucidate further the processes that govern the fluxes of carbon into and from the oceans, and to generate novel hypotheses. These are necessary prerequisites for developing a predictive capability for global environmental change.
AN: 3950184
9 of 200
TI: Overview of the U.S. JGOFS Bermuda Atlantic Time-series Study and the Hydrostation S program
AU: Michaels,-A.F.; Knap,-A.H.
AF: Bermuda Biol. Stn. for Res., 17 Biological Stn. Lane, Ferry Reach GE01, Bermuda
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 2-3, pp. 157-198
NT: Special issue: Ocean time-series: Results from the Hawaii and Bermuda research programs.
LA: English
AB: In October 1988 the Bermuda Atlantic Time-series Study (BATS) commenced sampling the Sargasso Sea in an area 85 km south-east of Bermuda as part of the U.S. Joint Global Ocean Flux Study (JGOFS). The scientific goal of the BATS program is to understand the causes of seasonal and interannual variability in ocean biogeochemistry both at this site and as it may relate to biogeochemistry of the rest of the ocean. Bermuda is also the site of other continuing and historical oceanic and atmospheric time-series programs. The ongoing Hydrostation S time-series commenced in 1954 and the biweekly profiles of temperature, salinity and oxygen provide data to link the more recent biogeochemistry time-series studies to the decadal variability in this region. Data on midwater particle fluxes have been collected continuously since 1976, ongoing measurements of atmospheric chemistry and wet and dry deposition began in 1980 and a long-term study of benthic boundary fluxes began in 1986. These various time-series studies complement each other and combine to make this region one of the most heavily documented oceanic environments in the world. The BATS and Hydrostation S programs each sample the ocean on a biweekly-to-monthly basis, a strategy that resolves the major seasonal patterns, interannual variability and decadal patterns. The Sargasso Sea also has more episodic or local processes, such as fluctuations that occur on scales of days to weeks and mesoscale eddies, and potentially patterns from the net advection of water past the sampling sites; these processes are more difficult to resolve by the one-dimensional time-series sampling strategy. The BATS program has begun to provide a coherent picture of the oceanic carbon and nutrient cycles in this region and the linkage between these cycles and the biological, chemical, physical and optical processes that control them. The significant interannual and decadal variability in the physical environment near Bermuda also allows us to examine the longer-term relationships between the physical forcing and biogeochemical response. Finally, the BATS program has proved a valuable platform to support other ancillary oceanographic research and technology development. These studies all benefit from the existence of the core time-series studies to add context and value to their more specific research efforts and they, in turn, further enhance the diversity of co-located measurements in this area.
AN: 3950183
10 of 200
TI: Quantification of non-algal attenuation in the Sargasso Sea: Implications for biogeochemistry and remote sensing
AU: Siegel,-D.A.; Michaels,-A.F.
AF: Dep. Geogr., Univ. California at Santa Barbara, Santa Barbara, CA 93106, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1996 vol. 43, no. 2-3, pp. 321-345
NT: Special issue: Ocean time-series: Results from the Hawaii and Bermuda research programs.
LA: English
ER: M (Marine)
AB: Observations of the diffuse attenuation coefficient spectrum (K sub(d)(z,t, lambda )), made as part of the U.S. Joint Global Ocean Flux Study (JGOFS), Bermuda Atlantic Time-series Study (BATS), show significant seasonal variations that do not covary with the patterns in chlorophyll a concentrations. The spectral structure of these changes indicates that the variations in optical properties are caused by detrital particulate and/or colored dissolved organic materials. Multiple regression analyses over wavelength are used to deconvolve this "colored dissolved or detrital material" (CDM) signal from the chlorophyll signal. Generally, CDM light attenuation is nearly as large as the chlorophyll-related attenuation and it exhibits a seasonal signal related to changes in mixed-layer depth. In the winter, values of CDM are roughly uniform throughout the upper 150 m of the mixed layer, whereas in the summer significantly reduced CDM values are found in a shallow mixed layer with elevated values in the seasonal pycnocline. The summer-time pattern appears to be caused by the combination of reduction of CDM within the mixed layer by photo-oxidation and its production at depth. This seasonal cycle is different than that observed for dissolved organic or particulate organic carbon at BATS. Hence, optical inferences of CDM are not directly related to biogeochemically relevant materials, such as dissolved organic carbon. Quantification of the photon flux absorbed by CDM can be used to assess the role of CDM quanta absorption in photochemical transformations. We suggest that CDM-regulated rates of photo-oxidation play a critical role in the regulation of near-surface dimethyl sulfide concentrations on a seasonal timescale. Last, the existence of a strong CDM signal requires modification of the techniques used to estimate chlorophyll from satellite ocean color sensors.
AN: 3950172
11 of 200
TI: Marine Environment Data Service report for 1995
AU: Glenn,-G.F.
CA: Northwest Atlantic Fisheries Organ., Dartmouth, NS (Canada)
SO: 1996 25 pp
LA: English
ER: M (Marine)
AB: An inventory of environmental data collected in the NAFO area, is contributed annually by MEDS to the NAFO subcommittee for the environment (STACFEN). This year's report (June 1996), is for the calendar year of 1995. The inventory shows that the data traditionally reported in this series, has been collected in quantities comparable with that of the past years. Also three developments relevant to NAFO environmental/ecosystem studies have come about. The United States has begun a survey in the Georges Bank. JGOFS has produced data for the Gulf and coastal areas. And, MEDS has quality assured and archived the historical set of CTD data delivered by BIO.
AN: 3912668
12 of 200
TI: The role of mesoscale hydrography on microbial dynamics in the Northeast Atlantic: Results of a spring bloom experiment
AU: Karrasch,-B.; Hoppe,-H.-G.; Ullrich,-S.; Podewski,-S.
AF: UFZ, Umwelforschungstent. Leipig-Halle, Gewaesserforsch. Am Biederiter Busch 12, 39114 Magdeburg, FRG
SO: J.-MAR.-RES. 1996 vol. 54, no. 1, pp. 99-122
LA: English
ER: M (Marine)
AB: During RV Meteor cruise No. 10 from May to June 1989 (JGOFS pilot study) bacterial and picocyanobacterial abundance, biomass, and bacterial production were estimated at two drift stations close to 47N, 20W and 58N, 20W in the northeast Atlantic. At 47N two different mesoscale hydrographic structures were sampled which divided the drift experiment into a cyclonic and an anticyclonic circulation phase. Transition from one phase to the next was clearly reflected by changes of the biological structure in the upper water column. The results suggest that within a specific type of hydrographic structure either a heterotrophic or an autotrophic system can be established, depending on the stage of bloom development. In conclusion: Depending on their origin and age, mesoscale hydrographic structures can be correlated with different stages of biological development. This leads to the mesoscale patchiness of biological measurements, which is a characteristic feature of the northeast Atlantic.
AN: 3883416
13 of 200
TI: Flavodoxin expression as an indicator of iron limitation in marine diatoms
AU: La-Roche,-J.; Murray,-H.; Orellana,-M.; Newton,-J.
AF: Brookhaven Natl. Lab., Upton, NY 11973, USA
SO: J.-PHYCOL. 1995 vol. 31, no. 4, pp. 520-530
LA: English
ER: M (Marine)
AB: We have previously shown that a marine chlorophyte expressed flavodoxin under iron limitation but not under other nutrient stress conditions. Here we use polyclonal antiserum raised against the diatom Phaeodactylum tricornutum Bohlin to show that a similar response is observe in this species. Using our antibody, western blotting techniques, and standard colorimetric detection (4-chloro-1-naphthol), we can detect at least a 25-50-fold increase in flavodoxin in iron-depleted compared to iron-replete cells. In iron-limited batch cultures of P. tricornutum, flavodoxin accumulation was inversely proportional to growth rate and was not detectable in cultures containing initially more than 750 nM of iron. We demonstrated that the accumulation of flavodoxin under iron stress is widespread among marine diatoms and that it may be possible to use the presence or absence of flavodoxin in natural marine diatom assemblages to detect iron limitation. However, our polyclonal antisera appears to be specific for diatoms and did not cross-react with Synechococcus sp., Micromonas pusilla (Butcher) Manton et Parke, Dunaliella tertiolecta Butcher, Chlorella sp., Emiliania huxleii (Lohm.) Hay et Parke, or Isochrysis galbana Parke. A reverse bioassay experiment was conducted with natural phytoplankton assemblages containing mainly diatoms from Long Island Sound and in shelf waters near Cape Hatteras, two areas not suspected to be iron-limited. Although flavodoxin was not detected in situ in these areas, natural populations of diatoms driven into iron limitation expressed flavodoxin. Flavodoxin was detected in mats of the diatom Rhizosolenia castracanei Cleve collected from the Equatorial Pacific during a JGOFS cruise in 1992, consistent with the hypothesis that iron may be limiting in this high-nutrient, low-chlorophyll region.
AN: 3863823
14 of 200
TI: [Distribution, abundance and significance of autotrophic pico - and nannoplankton in polar, temperate and subtropical regions.]
OT: Verbreitung, Abundanz und Bedeutung von autotrophem Pico- und Nannoplankton in polaren, temperierten und subtropischen Regionen
AU: Detmer,-A.
CA: Christian-Albrechts-Univ., Kiel (FRG). Mathematisch-Naturwissenschaftliche Fak.
SO: BER.-INST.-MEERESKD.-CHRISTIAN-ALBRECHTS-UNIV.-KIEL 1995 138 pp.
NT: Bibliogr.: 13 pages ref.
LA: German
ER: M (Marine)
AB: The aim of this thesis was to investigate the distribution, abundance and significance of autotrophic pico- and nannoplankton in different marine regions. For this purpose two springtime studies were conducted in the North Atlantic (JGOFS: Joint Global Flux Study; M21/2 expedition) and in the Southern Ocean (JGOFS; ANT X/6 expedition). Two further summertime studies were conducted in the Gotland Sea (central Baltic Sea; BAMBI'92 expedition: Baltic Microbial Biology Investigation) and in the Levantine Sea (eastern Mediterranean Sea; M25/2 expedition). Thus, regions of polar, temperate and subtropical climatic zones were taken into consideration and the influence of different hydrographic and chemical conditions on the occurrence and the distribution of autotrophic pico- and nannoplankton was estimated. Temporal and local patterns of phytoplankton development and regional differences were also considered. Experimental investigations of potential heterotrophy of coccoid cyanobacteria of the genus Synechococcus were conducted in order to complete the knowledge of physiological adaptations of one of the main organisms of autotrophic pico- and nannoplankton to different environmental conditions. During all expeditions, abundances and fluorescent properties of autotrophic pico- and nannoplankton were investigated directly on board by means of flow cytometry. To analyse the composition of the respective organism groups and to test the accuracy of cytometric results, epifluorescence microscopic investigations were conducted additionally. Moreover, the concentration of chlorophyll and the in situ primary production rates were measured in the size fractions of pico-, nanno- and mikrophytoplankton. A complex hydrographic variability characterized the situation in the temperate North Atlantic during spring 1992. Different, co-existing, pelagic systems of mesoscale extension were observed. These systems were characterized by different phytoplankton communities with mikrophytoplankton (mainly diatoms) or pico- and nannophytoplankton dominating (mainly coccoid cyanobacteria of the genus Synechococcus: 3,0-5,8 x 10 super(7) cells/l and autotrophic nannoflagellates: 2,0-3,2 x 10 super(7) cells/l). It appeared the dual importance of autotrophic pico- and nannoplankton during the spring succession in the eastern North Atlantic. On the one hand these organisms replace the typical springbloom of diatoms which collapses when silicate is depleted. On the other hand they maintain a minimum chlorophyll accumulation with a chl a concentration of 0.6 mu g/l even when hydrographic conditions are unstable as being typical in late winter and in early spring.
AN: 3862747
15 of 200
TI: Primary productivity and trace-metal contamination measurements from a clean rosette system versus ultra-clean Go-Flo bottles
AU: Sanderson,-M.P.; Hunter,-C.N.; Fitzwater,-S.E.; Gordon,-R.M.; Barber,-R.T.
AF: Duke Univ., Mar. Lab., Beaufort, NC 28516, USA
SO: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. 1995 vol. 42, no. 2-3, pp. 431-440
LA: English
ER: M (Marine)
AB: Primary productivity rates, measured during the 1992 United States Joint Global Ocean Flux Study (U.S. JGOFS) Equatorial Pacific (EqPac) process study with a new Trace-Metal clean rosette system (TM rosette) designed to be trace-metal clean, agreed within 5% with those determined using ultra-clean procedures that were previously shown to be trace-metal clean. The TM rosette system did not inhibit phytoplankton primary productivity rates. Using the TM rosette system, there was no contamination of Co, Ni, Cu, Cd or Pb, and only slight contamination of Fe and Zn, relative to ultra-clean collection. However, the slight contaminations were below levels that affect primary productivity rates. Therefore, systematic phytoplankton inhibition by trace-metal contamination appears to have been successfully eliminated with water collected using the TM rosette system.
AN: 3848627
16 of 200
TI: Alkalinity changes in the Sargasso Sea: Geochemical evidence of calcification?
AU: Bates,-N.R.; Michaels,-A.F.; Knap,-A.H.
AF: Bermuda Biological Station For Research Inc., 17 Biological Station Lane, Ferry Reach, GE01, Bermuda
SO: MAR.-CHEM. 1996 vol. 51, no. 4, pp. 347-358
LA: English
AB: Strong seasonal patterns in upper ocean total carbon dioxide (TCO2), alkalinity (TA) and calculated pCO2 were observed in a time series of water column measurements collected at the US Joint Global Ocean Flux Study (JGOFS) BATS site (31 degree 50'N, 64 degree 10'W) in the Sargasso Sea. TA distribution was a conservative function of salinity. However, in February 1992, a non-conservative decrease in TA was observed, with maximumdepletion of 25-30 mu moles kg-1 occuring in the surface layer and at the depth of the chlorophyll maximum ( similar to 80-100 m). Mixed-layer TCO2 also decreased, while surface pCO2 increased by 25-30 mu atm. We suggest these changes in carbon dioxide species resulted from open-ocean calcification by carbonate-secreting organisms rather than physical processes. Coccolithophore calcification is the most likely cause of this event although calcification by foraminifera or pteropods cannot be ruledout. Due to the transient increase in surface pCO2, the net annual transfer of CO2 into the ocean at BATS was reduced. These observations demonstrate the potential importance of open-ocean calcification and biological community structure in the biogeochemical cycling of carbon.
AN: 3846854
17 of 200
TI: HPLC analysis of algal pigments: A comparison exercise among laboratories and recommendations for improved analytical performance
AU: Latasa,-M.; Bidigare,-R.R.; Ondrusek,-M.E.; II,-M.C.K.
AF: Department of Oceanography, University of Hawaii at Manoa, Honolulu, HI 96822, USA
SO: MAR.-CHEM. 1996 vol. 51, no. 4, pp. 315-324
LA: English
AB: Pure individual and mixed pigment standards were distributed among Joint Global Ocean Flux Study (JGOFS) pigment analysts to estimate the variability of their spectrophotometric and chromatographic systems. To monitor the integrity of the pigments during the comparison exercise,chlorophyll and carotenoid standards were archived and periodically analyzed by high-performance liquid chromatography (HPLC). Pigment standards stored in the dark under nitrogen at -20 degree C were found to be stable for periods of at least one year. Results from three separate intercalibration exercises document a better agreement for spectrophotometric analyses than for HPLC. For the spectrophotometric comparisons, 90% of the pigments analyzed by participant laboratories were within plus or minus 6% of the mean ``consensus'' values. By contrast, 65 and 85% of the laboratories agreed to within plus or minus 10 and plus or minus 20%, respectively, when chromatographic analyses were compared. Chlorophyll absorption measurements obtained with a diode array-type spectrophotometer were 6-9% lower than those obtained with monochromator-type spectrophotometers. These underestimates probably result from chlorophyll fluorescence contamination associated with the optical configuration of the diode array spectrophotometer. It was also determined that HPLC methods which are not capable of separating monovinyl chlorophyll a from divinyl chlorophyll a can produce 15-25% overestimates of total chlorophyll a concentration in Prochlorococcus dominated oceanic waters. A simple dichromatic approach is described for eliminating this variable source of error caused by co-elution of these structurally-related pigments. The use of internal standards and periodic calibration checks with external standards is highly recommended for improving analytical performance.
AN: 3846852
18 of 200
TI: Impacts of storms on recent planktonic foraminiferal test production and CaCO sub(3) flux in the North Atlantic at 47 degree N, 20 degree W (JGOFS)
AU: Schiebel,-R.; Hiller,-B.; Hemleben,-C.
AF: Institute and Museum of Geology and Paleontology, Tubingen University, Sigwartstrasse 10, 72076 Tubingen, Germany
SO: MAR.-MICROPALEONTOL. 1995 vol. 26, no. 1-4, pp. 115-129
LA: English
AB: Planktic foraminiferal assemblages are well known to vary in accordance with seasonal fluctuations in ocean properties, periodic reproduction cycles, and variations between water masses. Here we report that storms also can significantly influence foraminiferal assemblages. During the RV Meteor cruise 21 to the Northeast Atlantic Ocean (BIOTRANS area), from March to May 1992, planktic foraminifera were sampled using a multiple opening-closing net. While sampling, two storms with wind forces up to 12 Beaufort caused intensified surface layer mixing with shifts in the depth of the upper ocean mixed-layer from 20-40 m to 170-240 m. Subsequently, planktic foraminiferal growth rates increased, resulting in an elevated quantity of small (100-150 mu m) tests (Phase 1). When the wind strength increased a second time, the mixed-layer deepened to a depth below the former position of the pycnocline, and again the abundance of small tests increased (Phase 2). During Phase 2, the weight of calcite in specimens of the productive zone reached its maximum. In the export zone, an associated increase in empty tests occurred with a lag time depending on the test sinking velocity. In the upper export zone, down to 700 m water depth, CaCO3 flux increased from 9.3 to 49.8 mg CaCO3 m-2 d-1 after the first storm and from 8.9 to 19.9 mg CaCO3 m-2 d-1 after the second storm. In the 700 to 2500 m depth interval, the flux increased from 5.1 mg CaCO3 m-2 d-1 to about 9.2 mg CaCO3 m-2 d-1. Thus, the standing stock of living foraminifera and export of empty tests from the productive zone increased after the storms, leading to pulses of CaCO3 exported from the surface to deep water.
AN: 3846400
19 of 200
TI: Micro-phytoplankton at the Equatorial Pacific (140 degree W) during the JGOFS EqPac Time Series studies: March to April and October 1992
AU: Iriarte,-J.L.; Fryxell,-G.A.
AF: Dep. Oceanogr. Texas A&M Univ., College Station, TX 77843-3146, USA
SO: DEEP-SEA-RES.-II-TOP.-STUD.-OCEANOGR. 1995 vol. 42, no. 2-3, pp. 559-583
LA: English
ER: M (Marine)
AB: Micro-phytoplankton (>20 mu m cell size) was sampled in the upper 200 m of the water column at the Pacific equator, 140 degree W during two JGOFS EqPac Time Series (TS) Studies, in order to determine the changes in the micro-phytoplankton assemblage between March-April and October 1992, to find the vertical distribution of micro-phytoplankton taxa, and to relate any changes in the environmental factors to micro-phytoplankton structure. Cell abundance and carbon biomass of three major taxonomic classes: diatoms, dinoflagellates and coccolithophorids were examined. During the abnormal warmth of El Nino 1992 (SST = 28-29 degree C), low abundance (<3000 cells/liter) and carbon biomass (<1 mu g C/liter) characterized the micro-phytoplankton structure, accompanied by low numbers of diatoms and coccolithophorids. Pennate diatoms, Pseudonitzschia delicatissima and thecate dinoflagellate, Oxytoxum variabile, were the most abundant organisms observed during March-April 1992 Time Series study. The micro-phytoplankton assemblage during El Nino conditions in March-April 1992 exhibited lower micro-phytoplankton species richness and abundance compared with October 1992. Also in contrast to the spring, in October 1992 the micro-phytoplankton assemblage showed large variability, mainly due to the passage of an instability wave through the study site. During this period, the coldest temperatures (SST = 25 degree C) were associated with increased abundance (range = 2 x 10 super(2) to 12 x 10 super(3) cells/liter) and richness in micro-phytoplankton species assemblage, which was again dominated by a colonial pennate diatom P. delicatissima. On the average, micro-phytoplankton carbon ranged from 0.5 to 4.0 mu g C/liter, where the diatom group consistently comprised the major part of the micro-phytoplankton autotrophic biomass in the upper 60 m. Large centric diatoms, such as Rhizosolenia species, as well as chains of P. delicatissima united in stepped colonies, and heavily silicified species of the Thalassionema/Thalassiothrix spp. complex were important groups contributing to the total micro-phytoplankton carbon biomass. At the equator, diatoms and dinoflagellates were restricted to the surface and to the upper 60 m, respectively, during both Time Series cruises, while coccolithophorid cells were concentrated at 90 m during TS I. The presence of an El Nino event and a instability wave during March-April and October 1992, respectively, may explain most of the variability in abundance and species richness found in the equatorial Pacific at 140 degree W during the study periods.
AN: 3831648
20 of 200
TI: Micro-phytoplankton of the Equatorial Pacific: 140 degree W meridianal transect during the 1992 El Nino
AU: Kaczmarska,-I.; Fryxell,-G.A.
AF: Dep. Biol., Mount Allison Univ., Sackville, NB E0A 3C0, Canada
SO: DEEP-SEA-RES.-II-TOP.-STUD.-OCEANOGR. 1995 vol. 42, no. 2-3, pp. 535-558
LA: English
ER: M (Marine)
AB: 1992 El Nino micro-phytoplankton (>15 mu m) were investigated in 40 samples collected throughout the upper 200 m of the water column at five stations during the U.S. JGOFS Survey I cruise TT007. Stations were located along the 140 degree W meridian at latitudes 9 degree N, 5 degree N, 2 degree N, 0 degree , and 5 degree S. Two hundred and twenty-four species of dinoflagellates, diatoms, coccolithophorids, silicoflagellates and one prasinophycean encountered are also known from other regions of the Pacific and/other warm water oceans. Total cell concentrations and concentrations of cells of representatives of the three major groups of phytoplankton observed in this study are lower than reported for La Nina phytoplankton. El Nino cell concentrations of micro-phytoplankton found in other studies vary and may be more or less than that of La Nina micro-phytoplankton cell concentrations. Distribution patterns of dinoflagellates, diatoms and coccolithophorids show a specific signature. Dinoflagellates are most common in near-surface waters of all stations, coccolithophorids are most common in the near surface of the extreme stations, and diatoms most common in the southern station. Relative abundances of diatoms and coccolithophorids increase with depth. Consequently, each of the stations differ in its biogeochemical characteristics and their potentials for export of particular biogenic remains. Total cell concentrations do not correlate well to chlorophyll a or to auxiliary pigments, supporting the conclusion that the biomass of phytoplankton in El Nino equatorial Pacific is dominated by cells smaller than investigated in this report.
AN: 3831647
21 of 200
TI: Coupled physical and biological modeling of the spring bloom in the North Atlantic (1): Model formulation and one dimensional bloom processes
AU: McGillicuddy,-D.J.,Jr.; McCarthy,-J.J.; Robinson,-A.R.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: DEEP-SEA-RES.-I-OCEANOGR.-RES.-PAP. 1995 vol. 42, no. 8, pp. 1313-1357
LA: English
ER: M (Marine)
AB: This is the first of two papers that introduce a mesoscale eddy resolving coupled physical and biological model system. The physical model consists of a quasigeostrophic interior with a fully coupled surface boundary layer. The nitrogen based biological model includes nitrate, phytoplankton, heterotroph and ammonium fields. This interdisciplinary model system is used to examine aspects of the 1989 JGOFS North Atlantic Bloom Experiment data set. This paper deals mainly with one dimensional processes and a companion paper addresses three dimensional phenomena. The data set consists of two time series of observations taken from different water masses in the mesoscale environment. The general features of the two time series are well represented by a one dimensional model when the mesoscale spatial variability in the initial condition is treated explicitly within the one dimensional framework. However, a significant bias is evident in the first time series as the sampling pattern began in a warm feature and moved toward colder ones. Mistaking spatial for temporal variability in this case results in an apparent sink of heat and source of nitrate in the data. Removing this bias with the one dimensional model results in an f-ratio that is almost a factor of two higher (0.64) than computed by other authors based on nutrient inventories and primary productivity measurements (0.37). The second time series was conducted in the interior of a mesoscale feature and spatial biasing is minimal. The model forms a seasonal thermocline and nitracline that compare quite well with the data in both magnitude and vertical extent. A subsurface ammonium maximum is generated by the model from an initially homogeneous profile that also agrees well with the data. Simulated primary productivity profiles match super(14)C incubations except on the final day of the simulation when surface nutrients appear in to have been exhausted slightly prematurely. Computed f-ratios are consistent with independent estimates based on uptake measurements. A systematic parameter dependence and sensitivity analysis is carried out on these results. The most sensitive parameters are the phytoplankton and heterotroph maximum growth rates. Detailed analysis of the behavior of the system indicates tight coupling between phytoplankton production and heterotrophic consumption even in the early stages of the bloom.
AN: 3828061
22 of 200
TI: Coupled physical and biological modelling of the spring bloom in the North Atlantic (2): Three dimensional bloom and post-bloom processes
AU: McGillicuddy,-D.J.,Jr.; Robinson,-A.R.; McCarthy,-J.J.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: DEEP-SEA-RES.-I-OCEANOGR.-RES.-PAP. 1995 vol. 42, no. 8, pp. 1359-1398
LA: English
ER: M (Marine)
AB: A set of three dimensional coupled physical and biological models is used to ascertain the importance of mesoscale dynamical activity during the 1989 JGOFS North Atlantic Bloom Experiment. First, various physical processes causing nutrient flux are studied with a simplified one compartment "nutrient model" utilized in an isolated vortex. A hierarchy of vertical transport processes is described for this case, ranging from the relatively minor fluxes caused by vortex stretching in the interior to the moderate transport resulting from the interaction of the interior and wind driven motions to the rather vigorous (3 m per day) effective transport caused by the propagation of the vortex. With these flux mechanisms in hand, the tuned four compartment biological model described in Part 1 is used to simulate the Small eddy in isolation. Together the propagation flux and the lifting of density surfaces caused by vortex evolution result in a twofold increase in mixed layer nitrate over that predicted by a one dimensional model. Enhanced phytoplankton and heterotroph production is associated with the elevated nutrient concentrations. Finally the three eddy configuration observed during the experiment is simulated. While all the previous vertical transports are active in this case, they are overshadowed by intense vertical motions associated with eddy-eddy interactions. Nutrient enhancements of up to an order of magnitude occur in the simulations that substantially increase both plant and animal production in localized regions for periods of weeks.
AN: 3828060
23 of 200
TI: Phytoplankton distributions and production in the Bellingshausen Sea, Austral spring 1992
AU: Savidge,-G.; Harbour,-D.; Gilpin,-L.C.; Boyd,-P.W.
AF: Queen's Univ. Belfast, Sch. Biol. and Biochem., Mar. Biol. Stn., Portaferry, Co. Down, Northern Ireland BT22 1PF, UK
SO: DEEP-SEA-RES.-II-TOP.-STUD.-OCEANOGR. 1995 vol. 42, no. 4-5, pp. 1201-1224
NT: Special Issue: Southern Ocean JGOFS: The U.K. Sterna Study in the Bellingshausen Sea.
LA: English
ER: M (Marine)
AB: Samples were taken from the open water region directly north of the ice-edge zone between 65.5 and 69.0 degree S, 83.5 and 88.0 degree W by R.R.S. Discovery between 23 November and 8 December 1992 for estimates of size-fractionated chlorophyll a concentrations and primary production and also for data on phytoplankton taxonomic distributions. The size-fractions (SF) considered were >18 mu m, 2-18 mu m and 0.2-2 mu m. The data confirmed the presence of a high chlorophyll zone (HCZ) immediately south of the surface boundary of the Southern Polar Front and also the absence of a classical stability induced ice-edge bloom, as inferred from a concurrent hydrographic survey. Extrapolation of the data obtained during the survey gave an estimate of primary production within the HCZ associated with the Southern Polar Front between longitudes 135-75 degree W in the Bellingshausen Sea, that is over an approximate distance of 2470 km, of 50 x 10 super(3) tonnes C day super(-1).
AN: 3825489
24 of 200
TI: Response of the copepod community to a spring bloom in the Bellingshausen Sea
AU: Atkinson,-A.; Shreeve,-R.S.
AF: Br. Antarct. Surv., Nat. Environ. Res. Counc., High Cross, Madingley Rd., Cambridge CB3 0ET, UK
SO: DEEP-SEA-RES.-II-TOP.-STUD.-OCEANOGR. 1995 vol. 42, no. 4-5, pp. 1291-1311
NT: Special Issue: Southern Ocean JGOFS: The U.K. Sterna Study in the Bellingshausen Sea.
LA: English
ER: M (Marine)
AB: During Austral spring 1992, R.R.S. James Clark Ross worked a five station transect in the Bellingshausen Sea. The transect spanned unproductive waters under solid pack ice to an open-water bloom in the north, three weeks later. This paper addresses the ontogenetic development of the copepod community, and from grazing experiments on females of five species investigates their trophic response to a spring bloom. Copepods dominated the mesozooplankton in both numbers and biomass. Their mean biomass in the top 600 m was low (0.85-1.5 mg drymass m super(-3)), which is similar to other high latitude oceanic localities in the Southern Ocean. Almost all the major copepod species underwent an ontogenetic seasonal ascent, from mainly below 250 m under the ice to the top 250 m at the open-water bloom stations. Based on the timings of migration, feeding and reproduction, the species appeared to fall into two broad categories.
AN: 3825488
25 of 200
TI: Microzooplankton and their role in controlling phytoplankton growth in the marginal ice zone of the Bellingshausen Sea
AU: Burkill,-P.H.; Edwards,-E.S.; Sleigh,-M.A.
SO: DEEP-SEA-RES.-II-TOP.-STUD.-OCEANOGR. 1995 vol. 42, no. 4-5, pp. 1277-1290
NT: Special Issue: Southern Ocean JGOFS: The U.K. Sterna Study in the Bellingshausen Sea.
LA: English
ER: M (Marine)
AB: Microzooplankton and their herbivorous activity were quantified on a transect in the Bellingshausen Sea along the 85 degree W meridian between 70 degree 15'S and 67 degree 30'S. The transect was worked during the Austral spring period of November-December 1992, with stations in pack-ice (Gertie/Herbie), ice-edge (Isolde), and open-waters (Jules and Katie) of the marginal ice zone (MIZ). Microzooplankton varied in their abundance in the surface mixed layer within the MIZ transect by more than an order of magnitude. Microzooplankton herbivorous activity also showed strong latitudinal gradients across the MIZ. A multiple regression model of microzooplankton herbivory was developed to produce an integrated analysis of their impact on phytogenic carbon flux. Microzooplankton in the mixed layer were estimated to graze 21 and 3260 mg phytoplankton-C m super(-2) day super(-1) at the southern pack-ice and northern open-water stations, respectively. This grazing flux accounted for 21 and 271% of the concurrent daily phytoplankton production, respectively. Microzooplankton are important in determining the fate of phytoplankton during the ice-melt period in the Bellingshausen Sea MIZ.
AN: 3825487
26 of 200
TI: Dissolved organic carbon in the upper ocean of the Central Equatorial Pacific Ocean, 1992: Daily and finescale vertical variations
AU: Carlson,-C.A.; Ducklow,-H.W.
AF: Bermuda Biol. Stn. Res., 17 Biological Lane, Ferry Reach GE-01, Bermuda
SO: DEEP-SEA-RES.-II-TOP.-STUD.-OCEANOGR. 1995 vol. 42, no. 2-3, pp. 639-656
LA: English
ER: M (Marine)
AB: Detailed depth profiles of dissolved organic carbon (DOC) were determined at the JGOFS Equatorial Pacific Time Series site at 0 degree , 140 degree W in March/April and October 1992. DOC concentrations in the top 200 m, determined with the high temperature combustion (HTC) method, showed no elevated values over previous wet chemical estimates and ranged from an average of 67 mu M C in the surface waters to 46 mu M C at 200 m. The average integrated DOC concentration over 200 m was 11.4 mol C m super(-2) in March/April and 11.0 mol C m super(-2) in October. Variability frequency (i.e. seasonal) was minimal despite large changes in many biogeochemical parameters. Vertical distribution of DOC was highly correlated with physical properties and remained relatively independent of biological properties. High frequency variability appeared to be governed by physical processes. DOC production and consumption in the equatorial Pacific were tightly coupled, resulting in little accumulation and export of labile DOC.
AN: 3824151
27 of 200
TI: Joint IOC-JGOFS panel on carbon dioxide. Fourth session, Plymouth, UK, 14-16 June 1993
CA: IOC, Paris (France)
CO: 4. Sess. Jt. IOC-JGOFS Panel on Carbon Dioxide, Plymouth (UK), 14-16 Jun 1993
SO: REP.-MEET.-EXPERTS-EQUIV.-BODIES-IOC 1994 63 pp
RN: IOC-JGOFS-IV-3 (IOCJGOFSIV3)
LA: English
ER: M (Marine)
AN: 3824137
28 of 200
TI: Bacterioplankton dynamics in the Equatorial Pacific during the 1992 El Nino
AU: Ducklow,-H.W.; Quinby,-H.L.; Carlson,-C.A.
AF: Coll. William and Mary, Virginia Inst. Mar. Sci., Box 1346, Gloucester Point, VA 23062, USA
SO: DEEP-SEA-RES.-II-TOP.-STUD.-OCEANOGR. 1995 vol. 42, no. 2-3, pp. 621-638
LA: English
ER: M (Marine)
AB: The stocks and dynamics of bacterioplankton in the upper 200 m were studied in detail providing daily temporal resolution and finescale vertical resolution during two ca 20-day occupations of a station on the equator at the U.S. JGOFS EqPac transect along 140 degree W longitude, in March-April and October 1992. Euphotic-zone bacterial biomass averaged 70% of phytoplankton carbon on the two cruises. This moderately high ratio was a consequence of low phytoplankton biomass, characteristic of high nutrient, low chlorophyll (HNLC) regimes, rather than high bacterial abundance, which averaged 6-8 x 10 super(8) cells l super(-1) in the upper 100 m. Turnover rates and thus production were low, with bacterial production (BP) averaging less than 20% of primary production (PP) for the two cruises. Biomass was higher and production was lower under the non-El Nino conditions prevailing in October, compared to the March-April observations made in El Nino conditions. Overall, bacterial production was a low fraction of primary production near the equator during both El Nino conditions. We suggest this might be the result of two possible but untested phenomena: (1) BP:PP is generally low (i.e. <20%) in oceanic waters, except during event-scale related disturbances of quasi-steady state conditions in trophic flow structure; and (2) bacteria respond more slowly in upwelling fields than phytoplankton, causing persistent uncoupling between the two groups. This latter condition might be relieved during El Nino when upwelliny is reduced.
AN: 3823973
29 of 200
TI: The oceanic mixed-layer pump
AU: Gardner,-W.D.; Chung,-Sung-Pyo; Richardson,-M.J.; Walsh,-I.D.
AF: Dep. Oceanogr., Texas A&M Univ., College Station, TX 77843, USA
SO: DEEP-SEA-RES.-II-TOP.-STUD.-OCEANOGR. 1995 vol. 42, no. 2-3, pp. 757-775
LA: English
ER: M (Marine)
AB: Diel variations in beam attenuation profiles in the upper water column were observed during Joint Global Ocean Flux Study (JGOFS) programs in the North Atlantic (North Atlantic Bloom Experiment-NABE) and Equatorial Pacific (EqPac). Beam attenuation due to particles in surface waters increased during the day by as much as 70% and decreased at night in both studies. In the equatorial Pacific the magnitude of the variations was larger during cool non-El Nino conditions (October, 1992) than during El Nino conditions (March/April 1992). However, the percent increase from the mean beam attenuation value for each time period was similar. The daytime increases result primarily from primary production, with possible contributions from changing optical effects of living cells. Nocturnal decreases in beam attenuation, reflecting particle loss, could be caused by grazing, remineralization, and the production of large particles (aggregates, fecal pellets) with subsequent settling. The nocturnal decreases also were associated with increases in the surface mixed layer depth and increases in nutrient concentrations. Part of these diel changes could result from mixing upward particle-depleted, nutrient-enriched water from below the daytime mixed layer. Since many biological and chemical species have strong gradients in the upper 100 m, regular oscillations in the depth of mixing can be an important forcing function for vertical exchange in surface waters. When it occurs, this "mixed-layer pump" is important in sustaining new primary production and in removing particles from surface waters, and should be included in models of oceanic surface mixing.
AN: 3823972
30 of 200
TI: The diel cycle in the integrated particle load in the Equatorial Pacific: A comparison with primary production
AU: Walsh,-I.D.; Chung,-Sung-Pyo; Richardson,-M.J.; Gardner,-W.D.
AF: Dep. Oceanogr., Texas A & M Univ., College Station, TX 77843, USA
SO: DEEP-SEA-RES.-II-TOP.-STUD.-OCEANOGR. 1995 vol. 42, no. 2-3, pp. 465-477
LA: English
ER: M (Marine)
AB: As part of the U.S. JGOFS EqPac process study beam c profiles were obtained during two time-series occupations of the equator at 140 degree W (TT008 and TT012). CTD/transmissometer profiles were routinely performed three times a day, roughly at dawn, noon, and just prior to sunset. Additionally, 'diel experiment' days of intensive profiling (every 3 h) were conducted twice during TT008 and three times during TT012. The beam attenuation profiles clearly show a diel cycle, with morning lows and evening highs. Transforming the beam c data into suspended particle concentration, and then integrating the particle load to the 1% and 0.1% light depths for each day yields the diel change in the particle load. Apart from changes in scattering and effective cross section, the diel change in the integrated particle load (IPL) represents the cycling of mass into and out of the small particle pool. The daytime increase in the integrated particle load ( Delta IPL, defined as the IPL from the evening minus the IPL from the morning profile) was converted to carbon units by assuming a 0.4 particulate organic carbon (POC) to particulate matter concentration (PMC) ratio. Our estimate of the net daily POC increase to the 1% light level averaged over the TT008 cruise was 26 mmol C m super(-2) day super(-1) (n = 7, SD = 7), and 41 mmol m super(-2) day super(-1) (n = 15, SD = 13) for TT012. The integration of the 0.1% light level was 29 mmol m super(-2) day super(-1) during TT008, and 41 mmol m super(-2) day super(-1) for TT012. As the optical method in situ includes the effects of growth, respiration, mixing, settling, grazing and aggregation, our data are not directly comparable to super(14)C uptake-based primary production measurements. Rather, the difference between the optical estimates of the change in the particle pool and primary production estimates can be ascribed to removal processes in situ, primarily grazing and aggregation.
AN: 3823964
31 of 200
TI: super(228)Ra-derived nutrient budgets in the upper Equatorial Pacific and the role of "new" silicate in limiting productivity
AU: Ku,-Teh-Lung; Luo,-Shangde; Kusakabe,-M.; Bishop,-J.K.B.
AF: Dep. Earth Sci., Univ. Southern California, Los Angeles, CA 90089-0740, USA
SO: DEEP-SEA-RES.-II-TOP.-STUD.-OCEANOGR. 1995 vol. 42, no. 2-3, pp. 479-497
LA: English
ER: M (Marine)
AB: super(228)Ra activities in the upper ocean (surface to similar to 850 m) of the equatorial Pacific between 9 degree N and 12 degree S along similar to 140 degree W were measured at five stations during the JGOFS EqPac 1992 Survey I cruise, when El Nino conditions prevailed in the area. The vertical profile of super(228)Ra at each station consists of measurements made on 2 to 3 m super(3) of water collected using submersible filtration systems in situ from 10-11 depths. super(228)Ra activities in the surface mixed layer range from similar to 5 dpm m super(-3) at northern stations to similar to 1.5 dpm m super(-3) near the equator. They decrease markedly between about 100 and 300 m, to concentration levels of 0.1-0.4 dpm m super(-3). The distributions manifest the occurrence of upwelling near the equator and downwelling between similar to 3 degree N and 10 degree N. On the basis of the super(228)Ra and nitrate distributions, estimations of upward vertical fluxes of nitrate at various depth horizons at each of the stations have been made. Maximum fluxes of similar to 2.0 to 3.5 mmol N m super(-2) day super(-1), averaging 2.6 mmol N m super(-2) day super(-1), occur near the base of the euphotic zone, about 100 m below sea surface. The average nitrate flux translates to a potential new production of about 17 mmol C m super(-2) day super(-1). While close to the result of the super(15)N tracer experiments, this new production estimate is significantly higher than the reported particulate organic carbon fluxes derived from the Th isotope and floating trap measurements. This implies that a significant fraction of the export production may have occurred in the form of dissolved organic carbon. The super(228)Ra-derived new production of 0.8 x 10 super(15) g C year super(-1) for the equatorial Pacific region east of the dateline is approximately one-half of the value obtained by Chavez and Barber (1987) for a non-El Nino period. The recycled fluxes of silicate, nitrate and phosphate to the euphotic layer bear molar ratios Si:N:P = 0.8:1:0.06. It is proposed that in upwelling regions of the equatorial Pacific, surface productivity is limited by the availability of "new" silicate, the silicate component that is decoupled from nitrate cycling and exported to the deep sea.
AN: 3823963
32 of 200
TI: The annual silica cycle in the Sargasso Sea near Bermuda
AU: Brzezinski,-M.A.; Nelson,-D.M.
AF: Dep. Biol. Sci., Univ. California, Santa Barbara, CA 93106, USA
SO: DEEP-SEA-RES.-I-OCEANOGR.-RES.-PAP. 1995 vol. 42, no. 7, pp. 1215-1237
LA: English
ER: M (Marine)
AB: The annual cycles of silicic acid and biogenic particulate silica (BSiO sub(2)) concentrations were examined from October 1988 through December 1992 at the JGOFS time-series site near Bermuda. Lithogenic particulate silica (LSiO sub(2)) concentrations were measured from August 1991 through December 1992 at the same site. Distinctly different seasonal patterns were observed in the concentration of biogenic and lithogenic phases. Integrated BSiO sub(2) concentrations in the upper 160 m were greatest (7.6-56.3 mmol BSiO sub(2) m super(2)) during an annual diatom bloom that occurred each year between January and April. In contrast, integrated LSiO sub(2) concentrations in the upper 160 m showed an annual maximum during July and August (2.05-2.12 mmol LSiO sub(2)/m super(2)) probably due to greater aeolian dust inputs during summer. The export of both BSiO sub(2) and LSiO sub(2) was examined with sediment traps deployed for 4 days each month from August 1991 through August 1992. The annual export of biogenic silica at 150 m (47.6 plus or minus 8.6 mmol BSiO sub(2)/m super(2)/y, s. d.) was dominated by a winter diatom bloom, which was responsible for 62% of the annual flux. In contrast, the export of LSiO sub(2) through 150 m was highest during July and August (0.039-0.064 mmol LSiO sub(2)/m super(2)/day), coincident with the summer maxima in suspended LSiO sub(2) concentrations. The close temporal coupling between maxima in suspended concentrations and vertical flux indicates that any delay between the appearance of BSiO sub(2) and LSiO sub(2) in the surface water and their subsequent export was less than our 30 day sampling interval.
AN: 3823925
33 of 200
TI: Downward export of respiratory carbon and dissolved inorganic nitrogen by diel-migrant mesozooplankton at the JGOFS Bermuda time-series station
AU: Dam,-H.G.; Roman,-M.R.; Youngbluth,-M.J.
AF: Dep. Mar. Sci., Univ. Connecticut, Groton, CT 06340, USA
SO: DEEP-SEA-RES.-I-OCEANOGR.-RES.-PAP. 1995 vol. 42, no. 7, pp. 1187-1197
LA: English
ER: M (Marine)
AB: Published calculations suggest that downward fluxes of respiratory carbon (RC) and dissolved inorganic nitrogen (DIN) associated with diel-migrant zooplankton are significant forms of export production. In this study, we examined variability in downward fluxes of RC and DIN due to diel-migrant mesozooplankton (200-2000 mu m) on seven occasions between 25 March and 8 April 1990 at the JGOFS (Joint Global Ocean Flux Study) station off Bermuda. Downward fluxes due to migrators crossing 150 m ranged from 6 to 41 mgC/m super(2)/day (RC) and 2 to 5 mgN/m super(2)/day (DIN). In comparison to gravitational fluxes of POC and PON measured with particle traps at 150 m during the same period, mesozooplankton RC flux was 18-70% of POC flux and mesozooplankton DIN flux was 17-82% of PON flux. If the RC and DIN fluxes due to migrators are considered in calculations of export production, the percentage of the production exported below 150 m over the study period would increase by an average of 25% for carbon and 21% for nitrogen. These results support the contention that metabolic activities of diel-migrant zooplankton should be included in calculations of export of carbon and nitrogen out of the mixed layer.
AN: 3823923
34 of 200
TI: A sediment trap investigation of sinking coccolithophorids in the North Atlantic
AU: Knappertsbusch,-M.; Brummer,-G.-J.A.
AF: Nat. Hist. Mus. Basel, Augustinergasse 2, 4001 Basel, Switzerland
SO: DEEP-SEA-RES.-I-OCEANOGR.-RES.-PAP. 1995 vol. 42, no. 7, pp. 1083-1109
LA: English
ER: M (Marine)
AB: Coccolith fluxes were studied in two vertically arranged and synchronized time series sediment traps at 700 m and 1025 m depth at JGOFS Station 47 degree N/20 degree W over a period of 3 weeks during May and June, 1990. A short but distinct pulse of the coccolithophorid Syracosphaera pulchra (Lohmann) was used to trace the vertical transport of coccoliths. For the bulk material the settling velocity was estimated to range from 137.8 m/day to 162.5 m/day. Maximum fluxes were 3.6 x 10 super(9)/day coccoliths/m super(2)/day in the upper and 2.3 x 10 super(9) coccoliths/m super(2)/day in the lower trap, or coccolith calcite fluxes of 42.6 mg/m super(2)/day and 28.7 mg/m super(2)/day. Prior to the pulse the average flux was 7.5 x 10 super(7) coccoliths/m super(2)/day (0.6 mg coccolith carbonate/m super(2)/day) at 700 m and 1.4 x 10 super(8) coccoliths/m super(2)/day (1.3 mg coccolith calcite/m super(2)/day) at 1025 m. Detailed studies of the fecal pellet content at 1025 m in five size fractions from < 32 mu m to > 500 mu m showed that during the S. pulchra pulse most coccoliths were transported in fecal strings larger than 500 mu m but that prior to this event a mixed coccolith and diatom flora was carried by several types of fecal pellet. Coccoliths in the fecal pellets showed no signs of dissolution. Mechanical breakage of coccoliths by zooplankton grazing, however, was severe. Profiles of suspended matter from the same time and location suggest that coccoliths, which were released into the water by coprorhexy and microbial degradation of the settling fecal matter, account for the 33% decline of coccolith calcite between the two traps. It is concluded that the export is characterized by a large variability in the flux of the different settling components, which is intimately related to day to day fluctuations in fecal pellet production by migrating zooplankton and nekton in the overlying mesopelagic zone.
AN: 3823918
35 of 200
TI: Spatial and temporal changes in the partitioning of organic carbon in the plankton community of the Sargasso Sea off Bermuda
AU: Roman,-M.R.; Caron,-D.A.; Kremer,-P.; Lessard,-E.J.; Madin,-L.P.; Malone,-T.C.; Napp,-J.M.; Peele,-E.R.; Youngbluth,-M.J.
AF: Horn Point Environ. Lab., Univ. Maryland, P.O. Box 775, Cambridge, MD 21613, USA
SO: DEEP-SEA-RES.-I-OCEANOGR.-RES.-PAP. 1995 vol. 42, no. 6, pp. 973-992
LA: English
ER: M (Marine)
AB: The vertical distribution of plankton (bacteria, nanozooplankton, microzooplankton, mesozooplankton, macrozooplankton and salps) biomass in the photic zone near the JGOFS time series station off Bermuda was examined during 2-3 week periods in August 1989 and in March/April 1990. The amount of phytoplankton carbon in the photic zone was lower in August as compared to March/April (398 and 912 mg C m super(-2), respectively). Total heterotrophic biomass in the photic zone was also lower in August as compared to March/April (1106 and 1795 mg C m super(-2), respectively). Taken together, bacteria and nanozooplankton constituted approximately 70% of the total heterotrophic carbon in the photic zone on both cruises. Considering their high weight-specific carbon demand relative to micro-, meso-, and macrozooplankton, it is clear that most of the carbon in the surface waters of the Sargasso Sea near Bermuda cycles through bacteria and flagellates-the "microbial loop". However, both seasonal (August vs. March/April) and within-cruise variations in the vertical flux of organic material were related to the biomass of macrozooplankton. Macrozooplankton biomass was lower in August than March/April (93 and 267 mg C m super(-2), respectively). There was more non-living carbon (detritus) than living carbon in the photic zone during the August cruise (70% of total organic matter) but about equal amounts of detritus and living carbon in March/April.
AN: 3823916
36 of 200
TI: Tracing, particle cycling in the upper ocean with super(230)Th and super(228)Th: An investigation in the Equatorial Pacific along 140 degree W
AU: Luo,-Shangde; Ku,-Teh-Lung; Kusakabe,-M.; Bishop,-J.K.B.; Yang,-Yong-Liang
AF: Dep. Earth Sci., Univ. Southern California, Los Angeles, CA 90089-0740, USA
SO: DEEP-SEA-RES.-II-TOP.-STUD.-OCEANOGR. 1995 vol. 42, no. 2-3, pp. 805-829
LA: English
ER: M (Marine)
AB: Vertical distributions of super(230)Th and super(228)Th were measured in large-volume (2000 to 3000 liter) seawater samples collected with the Multiple Unit In-Situ Large-Volume Filtration System (MULVFS) and in-situ Fe/Mn-fiber enrichment technique. The samples were from the upper similar to 800 m of the water column in the Central Equatorial Pacific along similar to 140 degree W during two survey cruises of JGOFS EqPac in February/March (Survey I) and August/September (Survey II) 1992. Significantly lower activities of super(230)Th and super(228)Th relative to those of their parent isotopes exist in the upper-ocean water column due to their particle-reactive behavior. The activities of these thorium isotopes also show large temporal variations, in response to surface productivity changes. During Survey I, a period of the El Nino, the super(230)Th and super(228)Th activities were higher than those measured during Survey II (a non-El Nino period), reflecting a depressed ocean productivity and particle flux under El Nino conditions. Vertical profiles of super(230)Th show a minimum at about 50 to 100 m, suggesting maximal particle scavenging in this depth range. Below this depth interval is a super(230)Th chemocline (rapid increase in super(230)Th activities with depth) and a super(228)Th activity maximum. The occurrence of the super(230)Th chemocline and the super(228)Th maximum just below the euphotic zone is a manifestation of active particle regeneration. Based on the extent of radioactive disequilibria between super(228)Th and super(228)Ra and between super(230)Th and super(234)U, we have estimated vertical fluxes of the two Th isotopes and of the particle mass. The export particle flux reaches a maximum in the lower portion of the euphotic zone, followed by a rapid decrease resulting from intensive particle remineralization in the super(230)Th chemocline/ super(228)Th maximum region. The scavenging rates of super(228)Th and super(230)Th are not balanced by their in-situ production and radioactive decay. The imbalance is attributable to their diffusional and advective transport. From the vertical profiles of particle fluxes derived from super(228)Th and super(230)Th, export fluxes of particulate organic carbon (POC) at the base of the euphotic zone are estimated to be 0.6-1.3 mmol C m super(-2)day super(-1) during El Nino, and 1.5-5.0 mmol C m super(-2)day super(-1) during the non-El Nino period. These values are small compared to the new production, indicating that much of the organic matter must be removed from the euphotic zone in dissolved form. Deeper at similar to 800 m, the POC fluxes are reduced to 0.14-0.50 mmol C m super(-2)day super(-1) (El Nino) and 0.5-1.1 mmol C m super(-2)day super(-1) (non-El Nino).
AN: 3822076
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TI: Latitudinal variations in mesozooplankton grazing and metabolism in the Central Tropical Pacific during the U.S. JGOFS EqPac study
AU: Zhang,-X.; Dam,-H.G.; White,-J.R.; Roman,-M.R.
AF: Dep. Mar. Sci., Univ. Connecticut, Groton, CT 06340-6097, USA
SO: DEEP-SEA-RES.-II-TOP.-STUD.-OCEANOGR. 1995 vol. 42, no. 2-3, pp. 695-714
LA: English
ER: M (Marine)
AB: Pigment ingestion rates by three size classes of mesozooplankton (200-500 mu m, 500-1000 mu m and 1000-2000 mu m) within the euphotic zone were measured during the Survey 1 (February/March) and Survey 2 (August/September) cruises of the 1992 United States Joint Global Ocean Flux Study (U.S. JGOFS) in the central equatorial Pacific (EqPac). Survey 1 was characterized by El Nino conditions while Survey 2 was characterized by typical climatological conditions. The small animals (200-500 mu m) contributed more than 50% (range: 34-80%) to the total mesozooplankton grazing reported here. Mesozooplankton grazing was higher within the equatorial region (5 degree S-5 degree N) than at higher latitudes (5 degree S-12 degree S, 5 degree N-12 degree N). The carbon-specific ingestion rates of both the large and small animals tended to be higher during Survey I than during Survey 2. In contrast to the carbon-specific ingestion rates, the mesozooplankton biomass during Survey 1 was lower than that during Survey 2. Thus, the higher ingestion rates during Survey 1 were offset by lower biomass and the mesozooplankton grazing was quite similar during Surveys 1 and 2. Mesozooplankton removal of chl a was higher within the high-phytoplankton-biomass equatorial region than at higher latitudes during Survey 1, but regional differences were not significant during Survey 2. Mesozooplankton community grazing was equivalent to an average daily removal of 3.0% (range: 0.5-7.7%) and 2.2% (range: 0.8-3.5%) of the total chl a standing stock within the euphotic zone during Surveys 1 and 2, respectively. However, mesozooplankton grazing was equivalent to a daily removal of 47% (range: 15-91%) and 36% (range: 23-66%) of the >5 mu m chl a standing stock within the euphotic zone during Surveys 1 and 2, respectively. Assuming a carbon-to-chl a ratio of 58, we estimate that mesozooplankton grazing removed an average of 6% (range: 2-12%) of super(14)C primary production during Survey 1, and 5% (range: 2-10%) during Survey 2. Removal rates were not significantly different between the equatorial region and the higher latitudes. Rates of respiration and ammonium excretion were estimated from empirical models based on animal weight and water temperature. Phytoplankton ingestion could not satisfy the estimated daily maintenance-carbon demands of mesozooplankton. The shortages were more pronounced in the large size fraction than in the small size fraction. The estimated ammonium excretion by the mesozooplankton could support 4-15% and 3-17% of super(14)C primary production during Surveys 1 and 2, respectively.
AN: 3821985
38 of 200
TI: Latitudinal gradients in zooplankton biomass in the Tropical Pacific at 140 degree W during the JGOFS EqPac study: Effects of El Nino
AU: White,-J.R.; Zhang,-Xinsheng; Welling,-L.A.; Roman,-M.R.; Dam,-H.G.
AF: Coll. Mar. Stud., Univ. Delaware, Lewes, DE 19958-1298, USA
SO: DEEP-SEA-RES.-II-TOP.-STUD.-OCEANOGR. 1995 vol. 42, no. 2-3, pp. 715-733
LA: English
ER: M (Marine)
AB: In 1992, as part of the equatorial Pacific study (EqPac) of the U.S. JGOFS Program, we collected zooplankton samples during a set of cruises that crossed the equator in the Pacific Ocean roughly along 140 degree W from 12 degree N to 12 degree S. The first cruise (Survey I) occurred during El Nino conditions in February-March when anomolously warm surface waters (>28 degree C) were present over most of the transect. The second cruise (Survey II) was during August-September when surface temperatures had returned to near or below the climatological mean over much of the region, and inorganic nitrogen and chlorophyll concentrations had increased compared with Survey I. Zooplankton biomass was higher in the equatorial region during Survey II compared with Survey I. For both cruises, chlorophyll and zooplankton biomass generally increased in the epipelagic zone (0-200 m) towards the equator. However, whereas primary production and chlorophyll were highest on or near the equator, zooplankton biomass was usually highest several degrees to the north and south of the equator. Zooplankton biomass was reduced below 100 m in newly upwelled water near the equator during both cruises, while biomass was distributed more evenly with depth in the presence of a weak thermocline at higher latitudes. The size structure of the zooplankton community changed between cruises, with more biomass in the >1000 mu m size fraction during Survey 2 in waters near (but not on) the equator. As noted by previous investigators, zooplankton biomass in this region appears to be in a dynamic balance between utilization of a relatively rich food supply and advection out of the area. Physical changes caused by El Nino interrupt this balance.
AN: 3821984
39 of 200
TI: Regional estimates of the export flux of particulate organic carbon derived from thorium-234 during the JGOFS EqPac program
AU: Buesseller,-K.O.; Andrews,-J.A.; Hartman,-M.C.; Belastock,-R.; Chai,-Fei
AF: Dep. Mar. Chem. and Geochem., Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: DEEP-SEA-RES.-II-TOP.-STUD.-OCEANOGR. 1995 vol. 42, no. 2-3, pp. 777-804
LA: English
ER: M (Marine)
AB: The upper ocean super(234)Th activity distribution at 77 stations was measured between 12 degree N and 10 degree S, and 95 degree W and 170 degree W in the spring and autumn of 1992. A regional scavenging model was used to estimate vertical export of particulate super(234)Th. Given the relatively high upwelling rates in this region, particularly at equatorial latitudes near 140 degree W, it was necessary to include upwelling of super(234)Th in our model in order to quantify particulate export. Using this export flux and the measured organic C or N to super(234)Th ratio on particles, one can empirically determine POC and PON fluxes for this region. The estimated particulate organic C flux varies spatially and temporally within this region, ranging from 1 to 7 mmol C m super(-2) day super(-1), with enhanced export occurring over the equator. Fluxes are also enhanced along 95 degree W coincident with a low temperature/high nutrient peak at 4 degree S. Along 140 degree W, particulate organic C export from the upper 100 m is on the order of 2 mmol C m super(-2) day super(-1) at latitudes beyond 4 degree N and 4 degree S, with an equatorial peak of 3-5 mmol C m super(-2) day super(-1) in both spring and fall. These results suggest that a relatively small per cent of the total production is exported locally on sinking particles (particle export/primary production <5-10%). This finding of low particle export is relatively insensitive to the chosen upwelling rates or particulate organic C/ super(234)Th ratios. Given the measured C/N ratio, particulate N fluxes from the upper 100 m would be 6 times lower than for POC.
AN: 3821983
40 of 200
TI: Zooplankton variability on the equator at 140 degree W during the JGOFS EqPac study
AU: Roman,-M.R.; Dam,-H.G.; Gauzens,-A.L.; Urban-Rich,-J.; Foley,-D.G.; Dickey,-T.D.
AF: Horn Point Environ. Lab., Univ. Maryland, P.O. Box 775, Cambridge, MD 21613, USA
SO: DEEP-SEA-RES.-II-TOP.-STUD.-OCEANOGR. 1995 vol. 42, no. 2-3, pp. 673-693
LA: English
ER: M (Marine)
AB: The vertical distributions of zooplankton biomass and community composition were measured on the equator at 140 degree W during March/April (19 days) and October 1992 (21 days). El Nino conditions prevailed during the March/April time series. The average integrated (200 m) zooplankton (>64 mu m) biomass was 32 mM C m super(-2) in March/April and 41 mM C m super(-2) in October. The overall cruise means were not significantly different; however during October zooplankton were more aggregated in the upper euphotic zone, there were more copepods >200 mu m, and there were more day/night differences in the vertical distribution of zooplankton biomass as a result of vertical migration behavior. Cyclopoid copepods were more abundant during the El Nino conditions of March compared to October. There were no apparent trends in integrated zooplankton biomass during the March/April time series. However, the species composition of the zooplankton community changed towards the end of the time series when meridional currents flowed to the south. Zooplankton biomass during the October cruise increased nearly five-fold with the passage of a tropical instability wave. A lag in the increase of zooplankton compared to nitrate and chlorophyll as well as changes in the zooplankton community composition over the time series reflect the response times of zooplankton to upwelling events.
AN: 3821980
41 of 200
TI: A biological acoustic survey in the marginal ice-edge zone of the Bellingshausen Sea
AU: Murray,-A.W.A.; Watkins,-J.L.; Bone,-D.G.
AF: Br. Antarct. Surv., High Cross, Madingley Rd., Cambridge CB3 0ET, UK
SO: DEEP-SEA-RES.-II-TOP.-STUD.-OCEANOGR. 1995 vol. 42, no. 4-5, pp. 1159-1175
LA: English
ER: M (Marine)
AB: An acoustic survey at 38 kHz was carried out from R.R.S. Discovery in the Bellingshausen Sea from 23 November to 7 December 1992 as part of the U.K. Joint Global Ocean Flux Study (JGOFS) Southern Ocean investigations [Turner D. and N.J.P. Owens (1995) Deep-Sea Research II, 42, 907-932]. A total of 285 targets were identified and described from the chart record of the echo sounder. Mean volume backscattering strength data were collected using an echo integration system. These data are used to describe the spatial and temporal variability of krill (Euphausia superba) distribution and biomass in the marginal ice-edge zone. Krill biomass density varied from a mean of 42 g m super(-2) during the first survey phase to 20 g m super(-2) on the second survey phase. The number of small swarms detected during the second phase was greater than during the first phase. On this first survey a large swarm (2.8 km in extent) had a potential biomass of 3.7 x 10 super(4) tonnes. Some calculations are presented to show the potential impact of krill on the flux of carbon in the area of the survey.
AN: 3820117
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TI: Plankton pigments and their derivatives as biomarkers for the description and assessment of phytoplankton succession and sedimentation in the North Atlantic.
OT: Plankton-Pigmente und deren Abbauprodukte als Biomarker zur Beschreibung und Abschaetzung der Phytoplankton-Sukzession und -Sedimentation im Nordatlantik
AU: Meyerhoefer,-M.
CA: Christian-Albrechts-Univ., Kiel (FRG). Mathematisch-Naturwissenschaftliche Fak.
SO: BER.-INST.-MEERESKD.-CHRISTIAN-ALBRECHTS-UNIV.-KIEL 1994 188 pp.
NT: Author's address: Inst. Meereskd. Univ. Kiel, Abt. Planktol., Duesternbrooker Weg 20, D-24105 Kiel, FRG. Bibliogr.: 21 pages ref.
LA: German
ER: M (Marine)
AB: The aim of this study was to follow the changes in vertical structure, composition and sinking of phytoplankton communities in space and time, and to determine the mechanisms that control these changes. In order to achieve this, photosynthetic pigments and their derivatives were chosen as biomarkers. Pigments were analyzed with HPLC (high performance liquid chromatography). Sampling was carried out during the JGOFS (Joint Global Ocean Flux Study) Pilot Study in four different areas of the North Atlantic (18 degree N/30 degree , 33 degree N/20 degree W, 47 degree Nl20 degree W and 58 degree N/20 degree W). Lagrangian drift experiments, lasting one to two weeks, were performed at these sites between 27th of March and 8th of June 1989. The main object was to follow and to investigate the northward spread of the spring bloom. Another study was carried out from 7th to 11th of August 1988 at 47 degree N/20 degree W.
AN: 3812866
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TI: WOCE studies in the South Atlantic. Cruise No. 28, 29 March - 14 June 1994
AU: Zenk,-W.; Mueller,-T.J.-(eds.)
SO: METEOR-BER. 1995 193 pp.
LA: English
ER: M (Marine)
AB: From 29 March to 14 June 1994 the German research vessel METEOR performed its 28th cruise, a journey in the subtropical South Atlantic devided into two legs. The main objectives were hydrographical and tracer observations in the frame work of the internationally coordinated World Ocean Circulation Experiment (WOCE). The cruise contributed to the WOCE Hydrographic Programme (WHP) and to the Deep Basin Experiment (DBE) in the Brazil Basin. Physical observations were supplemented by biological, air and environmental chemical and geological components, including a contribution to the Joint Global Ocean Flux Studies (JGOFS). The present cruise report contains a summary of the research objectives and comprises the research programme, a cruise narrative and preliminary observational results. The report was funded by the Deutsche Forschungsgemeinschaft (DFG) and the Bundesministerium fuer Bildung, Wissenschaft, Forschung and Technologie (BMBF).
AN: 3812692
44 of 200
TI: Carbon cycle and transport of water masses in the North Atlantic -- the winter situation. Cruise No. 27, 29 December 1993 - 26 March 1994
AU: Pfannkuche,-P.; Balzer,-W.; Schott,-F.-(eds.)
SO: METEOR-BER. 1994 134 pp.
NT: Bibliogr.: 38 ref.
LA: English
ER: M (Marine)
AB: METEOR cruise no. 27 combined the activities of four programmes focussing on the interactions of climatic changes and the ecosystem: - OMEX (Ocean Margin Experiment), - BI0-C-FLUX (Biological Carbon Transport in the Benthic Boundary Zone of the Open Ocean, - the working groups of the German JGOFS Programme (Joint Global Ocean Flux Study), - WOCE (World Ocean Circulation Experiment). The expedition M 27 started in Hamburg on December 29, 1993. Leg 1 (29.l2.l993-17.01.1994) was designated to the activities of German and various European OMEX projects. OMEX, sponsored by the European Union represents a multinational, interdisciplinary research programme which focusses on the exchange processes between the continental margin and the open ocean.
AN: 3812691
45 of 200
TI: Evidence of the potential influence of planktonic community structure on the interannual variability of particulate organic carbon flux
AU: Boyd,-P.; Newton,-P.
AF: Dep. Oceanogr., Univ. British Columbia, 6270 University Blvd., Vancouver, BC V6T 1W5, Canada
SO: DEEP-SEA-RES.-I-OCEANOGR.-RES.-PAP. 1995 vol. 42, no. 5, pp. 619-639
LA: English
ER: M (Marine)
AB: The functioning of the biological pump during spring blooms was assessed with biogeochemical data from JGOFS (Joint Global Ocean Flux Study) process studies in the NE Atlantic during 1989 and 1990. A comparison of the integrated primary productivity signal (estimated by the super(14)C technique and from changes in ambient surface-water [tCO sub(2)] and [NO sub(3) super(-)] during the spring blooms of the two years revealed close similarities. These observations suggest that the magnitude of the biological drawdown of CO sub(2) via photosynthetic activity during these periods was comparable. However, despite similarities in the magnitudes of these and other surface rate processes, sediment trap particulate organic carbon (POC) fluxes at 3100 m representing the spring bloom settlement events were 1.8 times greater in 1989 than in 1990. Taking into account the spatial and temporal resolutions of pelagic and deep trap datasets, these observations suggest that the coupling between organic carbon production in surface waters and its transfer to the deep ocean was stronger in the period studied in 1989 than in 1990. That is, the biological pump was more efficient in 1989. The size of the dominant phytoplankton species was observed to the principal difference between the two spring bloom data sets. The potential influence of the observed algal size differences on the vertical POC flux was quantified from size-fractionated productivity data in conjunction with a food web-vertical flux model. The derived POC fluxes from the surface layer were two times greater in spring 1989 than in the bloom period in 1990, and a comparison of these flux estimates with those from other methods is favourable. Extrapolation of these derived shallow POC fluxes to 3100 m with existing empirical algorithms yields deep POC fluxes that are consistent with those collected by sediment traps at this depth. Differences in algal size between the two spring blooms can thus account for the observed interannual differences in deep-water POC fluxes without the need to invoke interannual differences in unmeasured mid-water processes. This work provides a clear demonstration that although observations of oceanic productivity may yield the input to the biological pump, they cannot, on annual timescales, reliably provide information on the efficiency of the pump in transferring carbon to the deep ocean.
AN: 3810599
46 of 200
TI: Biotic and abiotic factors influencing sediment erosion and deposition on continental margins
AU: Webb,-D.G.; Grant,-J.
AF: Grad. Sch. Oceanogr., Univ. Rhode Island, Narragansett, RI 02882, USA
CO: 23. Benthic Ecology Meeting, New Brunswick, NJ (USA), 17-19 Mar 1995
SO: TWENTY-THIRD-BENTHIC-ECOLOGY-MEETING. Grassle,-J.P.;Kelsey,-A.;Oates,-E.;Snelgrove,-P.V.-eds. Rutgers-the-State-Univ.,-New-Brunswick,-NJ-USA.-Inst.-Marine-Coastal-Sciences 1995 vp
NT: Abstract only.
LA: English
ER: M (Marine)
AB: As part of the Canadian JGOFS Benthic Processes Study, we examined biotic and abiotic factors influencing sediment erosion and deposition in sediment cores collected during three cruises (May and December, 1993 and June, 1994) to the Gulf of St. Lawrence and Scotian Shelf and Slope. Using intact sediment cores, we conducted laboratory flume experiments on critical erosion thresholds and particle deposition in flow. Both erosion thresholds and particle deposition rate varied among stations and cruises, and appeared to covary more with biotic sediment properties (e.g. bacterial abundance, infaunal abundance and functional groupings) than abiotic properties (e.g. sediment grain size, porosity).
AN: 3809912
47 of 200
TI: CO sub(2) distributions in the Equatorial Pacific during 1991-1992 ENSO event
AU: Feely,-R.A.; Wanninkhof,-R.; Cosca,-C.E.; Murphy,-P.P.; Lamb,-M.F.; Steckley,-M.D.
AF: Pac. Mar. Environ. Lab., NOAA, 7600 Sand Point Way NE, Seattle, WA 98115-0070, USA
SO: DEEP-SEA-RES.-II-TOP.-STUD.-OCEANOGR. 1995 vol. 42, no. 2-3, pp. 365-386
LA: English
ER: M (Marine)
AB: As part of the U.S. JGOFS Equatorial Pacific Process Study, measurements of CO sub(2) species concentrations were made in the atmosphere and in the surface waters of the central and eastern equatorial Pacific during the boreal spring and autumn of 1992. Surface water fCO sub(2) data indicate significant differences between the springtime El Nino conditions and the autumn post-El Nino conditions. The autumn fugacity ( Delta fCO sub(2)) maxima were approximately 15-55 mu atm higher than in the spring. The lower surface Delta fCO sub(2) values in the spring data set were the result of: (i) advection of CO sub(2)-depleted water from the west at the equator near 170 degree W; and (ii) reduced upwelling and lower Delta fCO sub(2) distributions as consequence of lighter zonal winds in the eastern Pacific from 140 degree W to 110 degree W. Assuming the springtime data are representative of the El Nino conditions and the autumn data are representative of the post-El Nino conditions, it is estimated that the net annual CO sub(2) flux during the 1991-1992 ENSO period is 0.3 Gt C. Over 60% of this flux occurred during the 4-month period in the autumn when Delta fCO sub(2) values were close to normal. The net annual reduction of the ocean-atmosphere CO sub(2) flux during the 1991-1992 El Nino is estimated to be on the order of 0.5-0.7 Gt C.
AN: 3808486
48 of 200
TI: A U.S. JGOFS process study in the equatorial Pacific (EqPac): Introduction
AU: Murray,-J.W.; Johnson,-E.; Garside,-C.
AF: Sch. Oceanogr., Univ. Washington, P.O. Box 35794, Seattle, WA 98195-7940, USA
SO: DEEP-SEA-RES.-II-TOP.-STUD.-OCEANOGR. 1995 vol. 42, no. 2-3, pp. 275-293
LA: English
ER: M (Marine)
AB: This special issue contains data and scientific results from the JGOFS Process Study in the equatorial Pacific. Most of the contributions are from the U.S. JGOFS Process Study (EqPac) but the French and Australian results are represented as well. The equatorial Pacific plays a major role in the oceanic and atmospheric carbon cycles, and these studies are the first step for synthesizing the cycle of carbon and related elements in this region.
AN: 3808484
49 of 200
TI: Winter distribution of algal pigments in small- and large-size particles in the northeastern Atlantic
AU: Mejanelle,-L.; Laureillard,-J.; Fillaux,-J.; Saliot,-A.; Lambert,-C.
AF: Lab. Phys. Chim. Mar., Univ. Pierre Marie Curie, URA CNRS 353, 4, Place Jussieu, 75252 Paris Cedex 05, France
SO: DEEP-SEA-RES.-I-OCEANOGR.-RES.-PAP. 1995 vol. 42, no. 1, pp. 117-133
LA: English
ER: M (Marine)
AB: Particles were collected by filtration on GF/F filters and by vertical hauls of 50 mu m mesh-sized net throughout the water column (50-1700 m) in the northeastern Atlantic in January 1989 during the Medatlante I cruise, in the framework of the French JGOFS program. Particles were analysed for their organic carbon and algal chlorophyll and carotenoid pigments by high-performance liquid chromatography coupled with UV absorbance and fluorescence detection. Complementary analyses were performed on a surface sample for sterols and fatty acids by gas chromatography and gas chromatography/mass spectrometry. Organic carbon concentrations were 2-3 orders of magnitude higher in GF/F (10-50 mu g l super(-1)) than in net particles (0.01-0.06 mu g l super(-1)). The same ratio was encountered for pigments: 4-603 ng l super(-1) and 0.003-0.037 ng l super(-1), respectively. Among 11 GF/F samples collected between 500 and 1700 m, four samples contained pigments in detectable amounts (4-106 ng l super(-1)). Their pigment distribution pattern was close to deep GF/F samples, but differed from the pigment pattern of deep net-collected particles, mainly composed of fecal pellets. This latter sinking material was enriched in chlorophyll degradation pigments and showed higher values of the ratio (sum of carotenoids)/(sum of chlorophylls) than those observed in small-size particles. The combined information from pigments, sterols and fatty acids shows that Prymnesiophytes in a post bloom situation contributed to a major part of the surface autotrophs. Two processes of rapid transfer of organic matter between the surface and the deep Mediterranean water are discussed: fecal pellets of herbivorous plankton and sedimentation of aggregates partly linked to the presence of Prymnesiophytes.
AN: 3808084
50 of 200
TI: Thermodynamics of the carbon dioxide system in the oceans
AU: Millero,-F.J.
AF: Rosentiel Sch. Mar. and Atmos. Sci., Univ. Miami, Miami, FL 33149, USA
SO: GEOCHIM.-COSMOCHIM.-ACTA 1995 vol. 59, no. 4, pp. 661-677
LA: English
ER: M (Marine)
AB: In the next ten years, a number of studies on the carbonate system are planned as part of the JGOFS/WOCE programs. The carbon dioxide system will be studied by measuring at least two of the controlling parameters; pH, total alkalinity (TA), total inorganic CO sub(2) (TCO sub(2)), and the fugacity of CO sub(2) (f sub(CO2)). The other parameters can be calculated using thermodynamic relations. In the present paper the thermodynamic equations necessary to characterize the CO sub(2) system in the oceans as a function of salinity and temperature are given. This includes equations for the dissociation of carbonic acid, boric acid, phosphoric acid, silicic acid, water, hydrogen sulfide, and ammonia in seawater as a function of temperature (0 to 45 degree C) and salinity (0 to 45). The equations are of the form ln K sub(i) = A + B/T + C ln T, where A, B, and C are functions of salinity. Equations are also given for calculating the effect of temperature and salinity on the fugacity and pH of seawater using the carbonic acid constants of Roy et al.
AN: 3806998
51 of 200
TI: Mare cognitum. Science plan for research on marine ecology of the Nordic Seas (Greenland, Norwegian, Iceland Seas) 1993-2000
AU: Skjoldal,-H.R.; Noji,-T.T.; Giske,-J.; Fossaa,-J.H.; Blindheim,-J.; Sundby,-S.
SO: 1993 166 pp
NT: Copies available from: Inst. Mar. Res., PO Box 1870, N-5024, Bergen, Norway.
LA: English
ER: M (Marine)
AB: Norway has two lines of tradition in marine research which are of particular importance for conducting a large-scale ecosystem study of the Nordic Seas. One tradition is the fisheries investigations which have developed a high capability of studying and quantifying fish from a stock assessment point of view. This capability can now be turned to full use in marine ecology by allowing quantification of fish components of large marine ecosystems. The second tradition is the experience of conducting broad national marine ecological programs. Two such programs are PRO MARE (Program on Maine Arctic Ecology), which was a study of the Barents Sea ecosystem from 1984 to 1989, and MARE NOR (North-Norwegian Coastal Ecology Program), which was started in 1990 and will run through 1994. The first phase of MARE COGNITUM was started in 1993 as an institute program of the Institute of Marine Research. This initial phase is carried out in cooperation with the ongoing national programs MARE NOR and CARDEEP (Carbon dioxide and deep-water formation). It is the intention to launch the second phase of MARE COGNITUM as a major national program from 1995 onwards. The planning of MARE COGNITUM has been done in parallel with the international planning of the Global Ocean Ecosystem Dynamics (GLOBEC) Core Program. GLOBEC is an international program jointly sponsored by SCOR, IOC, ICES and PICES and is dedicated to understanding the effects of physical processes on predator-prey interactions and population dynamics of zooplankton and on their relation to ocean ecosystems within the context of the global climate system. In addition to the Core Program, the GLOBEC program structure shall be supported by a selected number of regional/national ecosystem research programs. The present plan is intended to be a Norwegian contribution to the group of national or regional GLOBEC programs. In addition, MARE COGNITUM will provide scientific contributions also to other large international programs, WOCE (World Ocean Circulation Experiment) and JGOFS (Joint Global Ocean Flux Study).
AN: 3802523
52 of 200
TI: Production and respiration in the 1989 North Atlantic spring bloom: An analysis of irradiance-dependent changes
AU: Kiddon,-J.; Bender,-M.L.; Marra,-J.
AF: EPA, 27 Tarzwell Dr., Narragansett, RI 02882, USA
SO: DEEP-SEA-RES.-I-OCEANOGR.-RES.-PAP. 1995 vol. 42, no. 4, pp. 553-576
LA: English
ER: M (Marine)
AB: Gross and net O sub(2) production rates at 47 degree N, 20 degree W over 13 days during the 1989 JGOFS North Atlantic (Spring) Bloom Experiment were measured. Gross O sub(2) production was measured by H sub(2) super(18)O uptake or calculated from super(14)C assimilation, and net O sub(2) production was measured by Winkler titration. Production versus irradiance P super(B)(1) curves were constructed from gross O sub(2) production rates (determined with in situ incubations) normalized to chlorophyll a concentration for the five days of highest total irradiance. Magnitudes of P super(B) sub(m), alpha and beta were high during the bloom. Chlorophyll-normalized gross O sub(2) production, integrated over the euphotic zone, was observed to be linearly related to integrated incident irradiance. This linear trend can be simulated with an algorithm using average values of P super(B) sub(m), alpha and beta parameters. 24 h O sub(2) respiration rates for each day appeared to consist of two components: one proportional to the production rate and involving respiration of carbon fixed during the same day's photoperiod, and the other independent of the production rate and respired carbon fixed prior to the day's photoperiod. Integrated over time and depth, these respiration components were of comparable magnitude, and together equalled about 60% of gross O sub(2) production. POC turnover times ranged from two days for near-surface waters up to about two weeks at the base of the euphotic zone.
AN: 3785285
53 of 200
TI: Protocols for the Joint Global Ocean Flux Study (JGOFS) core measurements
CA: IOC, Paris (France)
SO: MAN.-GUIDES-IOC 1994 no. 29, 126 pp
LA: English
ER: M (Marine)
AB: The Joint Global Ocean Flux Study (JGOFS) is an international and multidisciplinary study whose goal is to understand the role of the oceans in global carbon and nutrient cycles. The Scientific Council on Ocean Research describes this goal as an international programme to determine and understand the time-varying fluxes of carbon and associated biogenic elements in the ocean and to evaluate the related exchanges with the atmosphere, seafloor and continental boundaries. The present publication is a methods manual describing many of the current measurements used by scientists involved in JGOFS. The manual contains a set of accepted methods for most of the core JGOFS. Parameters and includes comments on variations to the methods and in some cases notes alternative procedures for the same measurement.
AN: 3765385
54 of 200
TI: Joint global ocean flux study. North Atlantic pilot study. Leg 3. Den Helder-Funchal-Reykjavik, 17 April to 31 May 1990 with research vessel TYRO
AU: Franz,-H.G.
CA: Nederlands Inst. voor Onderzoek der Zee, Texel (Netherlands)
SO: 1990 71 pp
NT: NTIS Order No.: PB91-157479/GAR.
RN: NIOZ-1990-6/SOZ CRUISE-1990-1 (CRUISE19901)
LA: English
ER: M (Marine)
AB: JGOFS leg 3 is part of the North Atlantic Pilot Study and is the second pelagic expedition within the national JGOFS program, with the aim to collect a data set for the spring situation in addition to the summer observations of 1989 (see shipboard report 1989-1 by H.J.W. de Baar et al.). To understand global change in atmospheric, oceanographic and climatic conditions as effected by human activity, the fluxes of carbon must be measured and analysed on a mondial scale. The pathways must be quantified and limiting factors in the production of organic matter, as well as the transport mechanisms must be understood in such a detail, that the dynamics of carbon and correlated elements in the biosphere such as plant nutrients can be simulated with mathematical models. JGOFS coordinates an international effort to create a database based on standardized and intercalibrated methods of measurement in the oceans. A target area with main stations in the North Atlantic Ocean was chosen. The cruise contributed to the collection of information on carbon compartments, primary and secondary production, biomass distribution and species composition of algae, bacteria and zooplankton in relation to the horizontal and vertical variation of nutrients and physics. (DBO)
AN: 3758616
55 of 200
TI: Vertical macrofaunal distribution in the soft sediments of the Gulf of St. Lawrence and the Scotian continental margin: A preliminary assessment of intersite differences in bioturbation potential
AU: Grehan,-A.J.; Scaps,-P.; Desrosiers,-G.; Juniper,-K.; Stora,-G.
AF: Univ. Quebec, GEOTOP, PB 8888 ST A., Montreal, PQ H3C 3P8, Canada
SO: VIE-MILIEU 1994 vol. 44, no. 2, pp. 101-107
LA: English
ER: M (Marine)
AB: Within the framework of a Canadian JGOFS programme to examine the factors and processes controlling carbon burial and regeneration in marine sediments, five sites, three in the Gulf of St. Lawrence and two on the Scotian continental margin, were visited during two multi-disciplinary cruises. Here we make a preliminary assessment of intersite differences in the likely impact of macrofaunal bioturbation based on a knowledge of the vertical distribution and feeding mode of the invertebrates encountered.
AN: 3756532
56 of 200
TI: Analyses of dissolved organic carbon in seawater: The JGOFS EqPac methods comparison
AU: Sharp,-J.H.; Benner,-R.; Bennett,-L.; Carlson,-C.A.; Fitzwater,-S.E.; Peltzer,-E.T.; Tupas,-L.M.
AF: Coll. Mar. Stud., Univ. Delaware, Lewes, DE 19958, USA
SO: MAR.-CHEM. 1995 vol. 48, no. 2, pp. 91-108
LA: English
ER: M (Marine)
AB: Results of a dissolved organic carbon (DOC) methods comparison are presented here in which five high temperature combustion (HTC) instruments and a wet chemical oxidation (WCO) method were used on a series of oceanic samples. The samples were collected during US JGOFS Equatorial Pacific Ocean cruises (EqPac) and most of the authors were involved with DOC analyses for the EqPac Program. Samples were collected with a "clean" protocol and were immediately quick frozen in replicate sample bottles. They were distributed by the first author to the other authors for "blind" analyses later on land on the stored samples. Results indicate that Equatorial Pacific oceanic DOC values in near surface waters are on the order of 60-70 mu M C and deep water values on the order of 35-40 mu M C. Since the "zero" carbon water contained a small, but measurable, amount of DOC, the sample values reported here may be slightly low. Because the lowest instrument blanks were equivalent to about 10 mu M C, it is suggested that even if there were no instrument blank at all and all this "blank" were in the "zero" carbon water, the oceanic sample concentrations could not be underestimated by more than 10 mu M C.
AN: 3750379
57 of 200
TI: Role of the ocean in climate changes
AU: Gulev,-S.K.
CO: Ocean Climate Data Workshop, Greenbelt, MD (USA), 18-21 Feb 1992
SO: PROCEEDINGS-OF-THE-OCEAN-CLIMATE-DATA-WORKSHOP,-FEBRUARY-18-21,-1992. J.-Churgin-comp. Commission-of-the-European-Communities,-Brussels-Belgium GREENBELT,-MD-USA GODDARD-SPACE-FLIGHT-CENT. 1992 pp. 51-64
LA: English
ER: M (Marine)
AB: The present program aimed at the study of ocean climate change is prepared by a group of scientists from State Oceanographic Institute. Academy of Science of Russia, Academy of Science of Ukraine and Moscow State University. It appears to be a natural evolution of ideas and achievements that have been developed under national and international ocean research projects such as SECTIONS, WOCE, TOGA, JGOFS and others. During last two decades main efforts were concentrated on quantitative experimental and model description of the ocean's role in the global climate change. In particular, the significance of the energy active zones of the ocean in the ocean-atmosphere interaction processes was defined; the connections between the sea surface temperature (SST) anomalies and the inter annual variations of the global atmosphere circulation were established; the stability of the meridianal ocean thermohaline circulation and it's influence on global climate was carefully concerned about. The derived results have proved the exclusively important role of the North Atlantic as a key feature in formation of the global "conveyor" of interoceanic circulation, which determines the long-period variability of the entire climate system.
AN: 3747039
58 of 200
TI: The earth observing system
AU: Wilson,-S.
CO: Ocean Climate Data Workshop, Greenbelt, MD (USA), 18-21 Feb 1992
SO: PROCEEDINGS-OF-THE-OCEAN-CLIMATE-DATA-WORKSHOP,-FEBRUARY-18-21,-1992. J.-Churgin-comp. Commission-of-the-European-Communities,-Brussels-Belgium GREENBELT,-MD-USA GODDARD-SPACE-FLIGHT-CENT. 1992 p. 17
NT: Summary only.
LA: English
ER: M (Marine)
AB: The talk began by describing the progress that had been made in developing instruments, observational techniques and algorithms for deriving satellite based oceanographic observations. Much of this early work used basic measurements from SEASAT and then many years of work to arrive at agreed upon algorithms. A number of standard products now available were illustrated. The Earth Observing System Data & Information System (EOSDIS) Pathfinder Program will make many of the existing data sets available to the research community for the cost of reproduction. EOSDIS will also act as a archival conduit for missions such as TOPEX and NSCAT. Charts were presented to depict planned and proposed ocean oriented satellite missions for altimeters, scatterometers and color scanners over the next decade. The talk went on to describe work that was needed in order to plan for a Global Ocean Observing System (GOOS). This includes answering questions on the spacial and temporal scales needed for monitoring as well as the types of measurements that will be required for a monitoring program. Work is underway for development of a monitoring system for El Nino/Southern Oscillation (ENSO). Also work is being done on the role of drifters, on economic impacts of GOOS and on inter-decadal variability. There is a need to focus on the tasks required in order to properly integrate satellite and in-situ observations as use this in developing follow-on programs to WOCE, TOGA and JGOFS. Eventually we need to use all these techniques in providing data to drive forecast models. The talk also stressed the need to develop GOOS as an international partnership within the existing international organizations.
AN: 3747036
59 of 200
TI: The JGOFS North Atlantic Bloom Experiment: An overview
AU: Ducklow,-H.W.
CO: Ocean Climate Data Workshop, Greenbelt, MD (USA), 18-21 Feb 1992
SO: PROCEEDINGS-OF-THE-OCEAN-CLIMATE-DATA-WORKSHOP,-FEBRUARY-18-21,-1992. J.-Churgin-comp. Commission-of-the-European-Communities,-Brussels-Belgium GREENBELT,-MD-USA GODDARD-SPACE-FLIGHT-CENT. 1992 pp. 205-228
LA: English
ER: M (Marine)
AB: The North Atlantic Bloom Experiment (NABE) of JGOFS presents a unique opportunity and challenge to the data management community because of the diversity and large size of biogeochemical data sets collected. NABE was a pilot study for JGOFS and has also served as a pilot study within the US NODC for management and archiving of the data sets. Here I present an overview to some of the scientific results of NABE, which will be published as an Introduction to a special volume of NABE results in Deep-Sea Research later this year. An overview of NABE data management is given elsewhere in the present report. This is the first collection of papers from the Joint Global Ocean Flux Study (JGOFS). Formed as an international program in 1987, JGOFS has four principal elements: modelling and data management, multidisciplinary regional process studies, a global survey of biogeochemical properties and long-term time series observatories. In 1989-90 JGOFS conducted a pilot process study of the spring phytoplankton bloom, the North Atlantic Bloom Experiment (NABE). JGOFS decided to conduct a large scale, internationally-coordinated pilot study in the North Atlantic because of its proximity to the founding nations of the project, the size and predictability of the bloom and its fundamental impact on ocean biogeochemistry. In 1989, six research vessels from Canada, Germany, The Netherlands, the United Kingdom and the USA and over 200 scientists and students from more than a dozen nations participated in NABE. Some of their initial results are reported in this volume.
AN: 3747032
60 of 200
TI: Data management for JGOFS: Theory and design
AU: Flierl,-G.R.; Bishop,-J.K.B.; Glover,-D.M.; Paranjpe,-S.
CO: Ocean Climate Data Workshop, Greenbelt, MD (USA), 18-21 Feb 1992
SO: PROCEEDINGS-OF-THE-OCEAN-CLIMATE-DATA-WORKSHOP,-FEBRUARY-18-21,-1992. J.-Churgin-comp. Commission-of-the-European-Communities,-Brussels-Belgium GREENBELT,-MD-USA GODDARD-SPACE-FLIGHT-CENT. 1992 pp. 229-250
LA: English
ER: M (Marine)
AB: We have constructed prototypes of the servers, methods, and constructed objects. We have much of the North Atlantic Bloom data entered into the system, along with various historical data sets and (separately) data from the SYNOP program. The process of documenting and training users will begin this year; assessment of the merits of the approach are still to come. However, we believe that, for on-going projects, on-line access to current data sets has many advantages. Likewise, the idea of building "extensible" data systems, analysis packages, and graphics packages should offer significant improvements in our abilities to share software.
AN: 3747017
61 of 200
TI: Data management for community research projects: A JGOFS case study
AU: Lowry,-R.K.
CO: Ocean Climate Data Workshop, Greenbelt, MD (USA), 18-21 Feb 1992
SO: PROCEEDINGS-OF-THE-OCEAN-CLIMATE-DATA-WORKSHOP,-FEBRUARY-18-21,-1992. J.-Churgin-comp. Commission-of-the-European-Communities,-Brussels-Belgium GREENBELT,-MD-USA GODDARD-SPACE-FLIGHT-CENT. 1992 pp. 251-274
LA: English
ER: M (Marine)
AB: Since the mid 1980s, much of the marine science research effort in the United Kingdom has been focused into large scale collaborative projects involving public sector laboratories and university departments, termed Community Research Projects. Two of these, the Biogeochemical Ocean Flux Study (BOFS) and the North Sea Project incorporated large scale data collection to underpin multidisciplinary modeling efforts. The challenge of providing project data sets to support the science was met by a small team within the British Oceanographic Data Centre (BODC) operating as a topical data centre. The role of the data centre was to both work up the data from the ship's sensors and to combine these data with sample measurements into online databases. The working up of the data was achieved by a unique symbiosis between data centre staff and project scientists. The project management, programming and data processing skills of the data centre were combined with the oceanographic experience of the project communities to develop a system which has produced quality controlled, calibrated data sets from 49 research cruises in 3.5 years of operation. The data centre resources required to achieve this were modest and far outweighed by the time liberated in the scientific community by the removal of the data processing burden.
AN: 3747016
62 of 200
TI: Management and assimilation of satellite data for JGOFS
AU: Evans,-R.
CO: Ocean Climate Data Workshop, Greenbelt, MD (USA), 18-21 Feb 1992
SO: PROCEEDINGS-OF-THE-OCEAN-CLIMATE-DATA-WORKSHOP,-FEBRUARY-18-21,-1992. J.-Churgin-comp. Commission-of-the-European-Communities,-Brussels-Belgium GREENBELT,-MD-USA GODDARD-SPACE-FLIGHT-CENT. 1992 pp. 275-294
LA: English
ER: M (Marine)
AB: Mr. Evans described the data flow that has been established and noted that understanding this flow was essential to understanding the data base. He noted that the complete suite of sensors as well as data transfers all need to be considered. This includes the process from initial satellite recordings to the final geophysical values that these represent. Further he illustrated the coordination that needs to be established between the satellite and field programs. Using SEAWIFS as an example, the usages and product delivery needs all must be considered. Presumed geophysical values must also undergo a quality assessment that involves in situ air and sea values. Finally you wind up with suites of data and data products that are available in time scales from near-real time to months or even years later. It was noted that changes in algorithms, correction factors and calibration require that data be available for reanalysis at later dates. Using AVHRR as an example, Mr. Evans showed the level of effort that was required in order to build this high quality time series data set, complete with error bars. This is the type of data that is most useful to climate studies but it required working and reworking buoy data used as sea truth and AVHRR data from satellites. Finally the some of the critical elements required for a successful system were: Timely access, simple mechanisms which allow one to include all partners in a large project, allowance for metadata so users are aware of how product was derived and distributed system interfaces that readily accessible and easy to use.
AN: 3747015
63 of 200
TI: Ocean time-series near Bermuda: Hydrostation S and the U.S. JGOFS Bermuda Atlantic Time-Series Study
AU: Michaels,-A.F.; Knap,-A.H.
CO: Ocean Climate Data Workshop, Greenbelt, MD (USA), 18-21 Feb 1992
SO: PROCEEDINGS-OF-THE-OCEAN-CLIMATE-DATA-WORKSHOP,-FEBRUARY-18-21,-1992. J.-Churgin-comp. Commission-of-the-European-Communities,-Brussels-Belgium GREENBELT,-MD-USA GODDARD-SPACE-FLIGHT-CENT. 1992 pp. 295-316
LA: English
ER: M (Marine)
AB: Bermuda is the site of two ocean time-series programs. At Hydrostation S, the ongoing biweekly profiles of temperature, salinity and oxygen now span 37 years. This is one of the longest open-ocean time-series datasets and provides a view of decadal scale variability in ocean processes. In 1988, the U.S.JGOFS Bermuda Atlantic Time-series Study began a wide range of measurements at a frequency of 14-18 cruises each year to understand temporal variability in ocean biogeochemistry. On each cruise, the data range from chemical analyses of discrete water samples to data from electronic packages of hydrographic and optics sensors. In addition, a range of biological and geochemical rate measurements are conducted that integrate over time-periods of minutes to days. This sampling strategy yields a reasonable resolution of the major seasonal patterns and of decadal scale variability. The Sargasso Sea also has a variety of episodic production events on scales of days to weeks and these are only poorly resolved. In addition, there is a substantial amount of mesoscale variability in this region and some of the perceived temporal patterns are caused by the intersection of the biweekly sampling with the natural spatial variability. In the Bermuda time-series programs, we have added a series of additional cruises to begin to assess these other sources of variation and their impacts on the interpretation of the main time-series record. However, the adequate resolution of higher frequency temporal patterns will probably require the introduction of new sampling strategies and some emerging technologies such as biogeochemical moorings and autonomous underwater vehicles.
AN: 3747014
64 of 200
TI: Automated in situ observations of upper ocean biogeochemistry, bio-optics, and physics and their potential use for global studies
AU: Dickey,-T.D.; Granata,-T.C.; Taupier-Letage,-I.
CO: Ocean Climate Data Workshop, Greenbelt, MD (USA), 18-21 Feb 1992
SO: PROCEEDINGS-OF-THE-OCEAN-CLIMATE-DATA-WORKSHOP,-FEBRUARY-18-21,-1992. J.-Churgin-comp. Commission-of-the-European-Communities,-Brussels-Belgium GREENBELT,-MD-USA GODDARD-SPACE-FLIGHT-CENT. 1992 pp. 317-354
LA: English
ER: M (Marine)
AB: The processes controlling the flux of carbon in the upper ocean have dynamic ranges in space and time of at least nine orders of magnitude. These processes depend on a broad suite of inter-related biogeochemical, bio-optical, and physical variables. These variables should be sampled on scales matching the relevant phenomena. Traditional ship-based sampling, while critical for detailed and more comprehensive observations, can span only limited portions of these ranges because of logistical and financial constraints. Further, remote observations from satellite platforms enable broad horizontal coverage which is restricted to the upper few meters of the ocean. For these main reasons, automated subsurface measurement systems are important for the fulfillment of research goals related to the regional and global estimation and modeling of time varying biogeochemical fluxes. Within the past few years, new sensors and systems capable of autonomously measuring several of the critical variables have been developed. The platforms for deploying these systems now include moorings and drifters and it is likely that autonomous underwater vehicles (AUV's) will become available for use in the future. Each of these platforms satisfies particular sampling needs and can be used to complement both shipboard and satellite observations. In the present review, 1) sampling considerations will be summarized, 2) examples of data obtained from some of the existing automated in situ sampling systems will be highlighted, 3) future sensors and systems will be discussed, 4) data management issues for present and future automated systems will be considered, and 5) the status of near real-time data telemetry will be outlined. Finally, we wish to make it clear at the outset that the perspectives presented here are those of the authors and are not intended to represent those of the United States JGOFS program, the International JGOFS program, NOAA's C&GC program, or other global ocean programs.
AN: 3747013
65 of 200
TI: Biochemistry of the Arabian Sea: Present information and gaps
AU: Lal,-D.
SO: BANGALORE-INDIA INDIAN-ACAD.-OF-SCI. 1994 253 pp
LA: English
ER: M (Marine); B (Brackish)
AB: This special issue deals with selected topics relating to biogeochemical processes in the Arabian Sea. Contributions to these are solicited from experts with a view to bring together a critical mass of information about these processes, specially those which have been highlighted from recent studies in the Arabian Sea and in the equatorial Indian Ocean, and are relevant to JGOFS (Joint Global Flux Study) programme in the Arabian Sea. It contains 12 articles and are abstracted in this database.
AN: 3732844
66 of 200
TI: The CO sub(2) system in seawater
AU: Millero,-F.J.
AF: Rosenstiel Sch. Mar. Atmos. Sci., Univ. Miami, Miami, FL, USA
SO: SEA-TECHNOL. 1994 vol. 35, no. 10, pp. 17-20
LA: English
ER: M (Marine)
AB: The JGOFS (Joint Global Ocean Flux Studies) program is committed to obtaining a global description of the carbon cycle in the oceans and developing the ability to predict on a global scale the response of the oceans to changes in the carbon cycle. An agreement between JGOFS and World Ocean Circulation Experiment (WOCE) has made it possible to conduct measurements of the controlling parameters on WOCE hydrographic program cruises. The National Oceanic & Atmospheric Administration Office of Global Programs sponsors the Ocean-Atmosphere Carbon Dioxide Exchange Program that studies the rate at which CO sub(2) is taken up and released by the oceans. Over the last five years, a number of studies on the carbonate system have been made in the world oceans as part of these programs. At least two of the CO sub(2) parameters have been determined.
AN: 3704216
67 of 200
TI: Scientific requirements for an abyssal benthic laboratory
AU: Thiel,-H.; Kirstein,-K.-O.; Luth,-C.; Luth,-U.; Luther,-G.; Meyer-Reil,-L.-A.; Pfannkuche,-O.; Weydert,-M.
AF: Inst. Hydrobiol. Fischereiwissenschaft, Univ. Hamburg, Zeiseweg 9, 22765 Hamburg, FRG
SO: J.-MAR.-SYST. 1994 vol. 4, no. 6, pp. 421-439
LA: English
ER: M (Marine)
AB: In view of the numerous problems related to global change, as a first step emphasis should first be on the role of the oceans and their inherent processes, which are the focus of such international programmes as the World Ocean Circulation Experiment (WOCE) and the Joint Global Ocean Flux Study (JGOFS). Multi-disciplinary registration of key events at selected key sites investigating the variability in time and space are of the utmost importance. The same methods and techniques must be used for the study of human impacts on the deep oceans caused by mining of metalliferous resources and by waste disposal as well as in basic studies. However, the investigation of the inner space of our planet has certain requirements. As long-term and large-scale investigations become more and more important, development of automized systems, largely independent from research vessels will be required. This will demand high capacities of energy for all technical functions as well as high storage capacities for data and samples. As a consequence the needs for two different - although overlapping - functional approaches are defined for future deep-sea deployments. (A) A system for long-term registration of the natural variability and long-term monitoring of human impacts; (B) A system for short-term observations and short-time experimentations. This report summarizes their technological demands. The envisioned interdisciplinary technology should deliver information on physical, biological and geochemical processes and their variabilities in the deep oceans. The prospected systems need to have the ability for real time video observation, data transfer and experimental manipulation, as well as sensing and sampling facilities with large storage capacities for long-term deployments.
AN: 3699804
68 of 200
TI: Seasonal patterns of ocean biogeochemistry at the U.S. JGOFS Bermuda Atlantic Time-series Study Site
AU: Michaels,-A.F.; Knap,-A.H.; Dow,-R.L.; Gundersen,-K.; Johnson,-R.J.; Sorensen,-J.; Close,-A.; Knauer,-G.A.; Lohrenz,-S.E.; Asper,-V.A.; et-al.
AF: Bermuda Biol. Stn. Res., Inc., St. Georges, GE-01, Bermuda, USA
SO: DEEP-SEA-RES.-A-OCEANOGR.-RES.-PAP. 1994 vol. 41, no. 7, pp. 1013-1038
LA: English
ER: M (Marine)
AB: Seasonal patterns in hydrography, oxygen, nutrients, particulate carbon and nitrogen and pigments were measured on monthly cruises at the Bermuda Atlantic Time-series Study Site, 80 km Southeast of Bermuda. Between October 1988 and September 1990, the annual cycle was defined by the creation of 160-230 m-deep mixed layers in February of each year and a transition to strong thermal stratification in summer and fall. The 230 m mixed layer in February 1989 resulted in mixed-layer nitrate concentrations of 0.5-1.0 mu mole/kg, carbon fixation rates over 800 mg C/m super(2)/day, and a phytoplankton bloom with chlorophyll concentrations over 0.4 mg m super(-3). Chlorophyll a, particulate organic matter, inorganic nutrients and primary production had returned to pre-bloom levels the following month with the exception of a chlorophyll maximum layer at 100 m. Particle fluxes at 150 m in February 1989 reached 56 mg C/m super(2)/day and 11 mg N/m super(2)/day (0.77 mmole N/m super(2)/day). Estimates of new production during the bloom period calculated from changes in oxygen and nitrate profiles ranged from 100 to 240 mmoles N/m super(2), significantly higher than the sediment trap fluxes and approaching the measured total production rates. In spring of 1990, mixed layer depths did not exceed 160 m, nitrate was rarely detectable in the upper euphotic zone, chlorophyll a concentrations were similar to 1989, and particulate organic matter concentrations were lower. The period of elevated biomass lasted for 3 months in 1990, and phytoplankton pigment composition varied between cruises. The average rates of primary production and particle flux were higher in 1990 than those measured in the spring of 1989, despite the differences in mixed layer depth. Throughout both years, NO sub(3):PO sub(4) ratios in the upper thermocline exceeded Redfield ratios. The maintenance of this pattern requires a net uptake of PO sub(4) between 150 and 250 m, a depth range usually associated with net remineralization. The exact mechanism that maintains elevated PO sub(4) uptake and its implication for the nutrient supply to the euphotic zone remain unknown.
AN: 3693257
69 of 200
TI: Emerging technologies in biological sampling. A report of SCOR Working Group 90
AU: Herman,-A.W.
AF: Bedford Inst. Oceanogr., Dep. Fish. and Oceans, P.O. Box 1006, Dartmouth, NS B2Y 4A2, Canada
CA: UNESCO, Paris (France)
SO: UNESCO-TECH.-PAP.-MAR.-SCI. 1993 no. 66, 52 pp
LA: English
ER: M (Marine)
AB: Technology development as we know it today is and should be driven by the science in which it is applied. Initial science objectives of large scale international programs, such as JGOFS and GLOBEC, outline sampling technology needs at their outset and initiate specific technological development. Described here are a variety of technologies - recent and not-so recent - which are emerging in the 90's and will provide biological oceanography with newer and more powerful tools and greater insights with a wider scope of measurements. There are three areas of focus: 1) Platforms, 2) Fluorescence and 3) Particles. Under 'Platforms', vehicles and methods of sampling are described leading the way into a discussion of the sensors used in the measurement of various biological parameters. In this recent scientific age of climatic influence of ocean ecology, long-term monitoring has been identified as a need which is presently encouraging new developments in mooring technology. In some cases specific measurement technologies which have been only recently developed, e.g. 'pump and probe fluorescence' or the 'SeaWiFS', are emerging technologies which are destined for broader and more intensive applications. Many technologies are potentially overlapping in application. For example, the historical technology of light attenuance has been recently integrated with the emerging technology of flow cytometry yielding new insights in patterns of primary production. The coalition of three technologies, that is, acoustics and the emerging technologies of video and optical plankton counting are also described indicating their future potential for the counting and identification of zooplankton.
AN: 3690659
70 of 200
TI: Mooring line motions and sediment trap hydromechanics: In situ intercomparison of three common deployment designs
AU: Gust,-G.; Michaels,-A.F.; Johnson,-R.; Deuser,-W.G.; Bowles,-W.
AF: Arbeitsber. Meerestech. 1, Tech. Univ. Hamburg-Harburg, 21079 Hamburg, FRG
SO: DEEP-SEA-RES.-A-OCEANOGR.-RES.-PAP. 1994 vol. 41, no. 5-6, pp. 831-857
LA: English
ER: M (Marine)
AB: Trap array characteristics were monitored concurrent with particle collections for surface-tethered and bottom-moored cones and cylinders (MultiPITs) at the North Atlantic OFP-JGOFS site in the Sargasso Sea. At depths ranging from 145 to 3200 m, velocities of approaching fluid and those inside the traps were recorded at 5 Hz in bursts of 3-10 min every half hour during particle collections. A thermistor, a high resolution pressure gauge and two inclinometers concurrently monitored trap movements. Burst-averaged slip velocities experienced by both shallow and deep tethered traps reached 37 cm s super(-1), while a bottom-moored trap recorded 10-day averaged speeds of 4 cm s super(-1). Independent of deployment technique, for both cones and cylinders, flow cells inside the traps led to an intense flushing of fluid and particles. None of the surface-tethered traps tilted more than 8 degrees from vertical, even under strong flow accelerations. Tether-line motions, induced by the surface waves, generated high flow acceleration peaks of trap arrays at all depths, even for bungie-cord decoupled MultiPIT arrays. The flow cells inside traps were thus agitated with the result of intense turbulence prevailing close to the collection cup in the apex of tethered cones. Moored cone arrays recorded less dynamic environments. Trap fluxes by tethered cones were up to a factor of 8 smaller than by tethered MultiPITs at the same depth and time, cones collected more material with higher approaching fluid flows (untested so far for cylinders), and for the same conical geometry tethered traps collected less material than bottom-moored traps. The in situ deployments revealed substantial flow- and geometry-related differences in collection behavior among the different trap arrays, all of which deviated from steady-state flume simulation results. The diameter of the retention cup at the trap apex rather than the trap mouth diameter may be a controlling design parameter of particle collection rates for conical traps. Efforts to link trap and in situ fluxes require that hydrodynamics of individual trap arrays at depth are monitored, including line motions. Drift velocities rarely coincided with trap-experienced approach velocities. Trap simulation studies utilizing steady-state flume flows may be accurate only under very specialized conditions. Our data provide a hydrodynamic rationale for earlier recommendations by others of cylinders with adequate length-width ratio.
AN: 3689407
71 of 200
TI: Seasonal succession in the pelagic ecosystem of the North Atlantic and the utilization of nitrogen
AU: Taylor,-A.H.; Harbour,-D.S.; Harris,-R.P.; Burkill,-P.H.; Edwards,-E.S.
AF: Plymouth Mar. Lab., Prospect Pl., West Hoe, Plymouth PL1 3DH, UK
SO: J.-PLANKTON-RES. 1993 vol. 15, no. 8, pp. 875-891
LA: English
ER: M (Marine)
AB: Observations during the Joint Global Ocean Flux Study (JGOFS) North Atlantic Bloom Experiment in 1989 are compared with a mixed-layer model of phytoplankton seasonal succession in which the latitudinal variation of the succession is driven by physical forcing. In the model, the first phytoplankton groups to grow at the end of the winter are those with the fastest intrinsic growth rates: the phytoflagellates and picophytoplankton. The increases of these groups are soon halted by the rapid growth of microzooplankton and heteroflagellates whereupon they are succeeded by diatoms, the next fastest growers. With depletion of silicate, the diatom bloom ends and is briefly replaced by phytoflagellates and picophytoplankton, before these in turn are replaced by slower growing dinoflagellates. Differences in the physical forcing cause the timings and magnitudes of these changes to vary with latitude. By sampling the model results at the times and places of the JGOFS observations, it is shown that the major changes of populations and nutrients are reproduced, as are many production and grazing rates. The model results suggest the nature of nutrient utilization in the region. While nitrate and silicate are both reduced to low values at 47 degree N, only silicate is depleted at 60 degree N. Nitrate is not depleted at northern latitudes due to the greater depth of the mixed layer, more intense vertical mixing and the shorter season, so that phytoplankton have more nutrients to utilize and a shorter time in which to do it. Phytoflagellates and picophytoplankton are unable to utilize all the inorganic nitrogen because of the grazing by the micrograzers, and diatoms because of silicate depletion. Dinoflagellates are slow growing and only have sufficient time to deplete the nitrogen at low latitudes. There is no need to invoke limitation by a trace nutrient, such as iron, to reproduce the events in the NE Atlantic during 1989.
AN: 3687948
72 of 200
TI: IOC Training course on ocean flux monitoring in the Indian Ocean, organized with the support of the government of Germany, Kenya Marine and Fisheries Research Institute, Mombasa, Kenya, 15-27 November 1993
CA: Intergovernmental Oceanographic Comm., Paris (France)
SO: TRAIN.-COURSE-REP.-IOC no. 26, 21 pp
LA: English
ER: M (Marine)
AB: The Training Course was designed to introduce scientists of the region to the project on the Joint Global Ocean Flux Study (JGOFS), test the JGOFS Core Measurement Protocols whether they would be adaptable for developing countries in the region, and acquaint the scientists with current scientific and technical knowledge in marine sciences. The two-week course was held in co-operation with the Kenya Marine and Fisheries Research Institute (KMFRI) in Mombasa, Kenya, and consisted of lectures, exercises and laboratory work to analyze samples and data collected during a half-day research cruise.
AN: 3680834
73 of 200
TI: Nordatlantik 1993. Cruise No. 26, 24 August-26 November 1993
AU: Suess,-E.; Kremling,-K.; Mienert,-J.-(eds.)
SO: METEOR-BER. HAMBURG-FRG LEITSTELLE-METEOR.-INST.-FUER-MEERESKUNDE 1994 no. 94-4, 256 pp
LA: English
ER: M (Marine)
AB: The 26th voyage of RV METEOR to the North Atlantic, the Skagerrak, the Norwegian, East Greenland and Barents Seas consisted of three legs whose research programs served several large integrated, and multi-disciplinary projects. During the first leg, M 26/1, the programs were related to WOCE (World Ocean Circulation Experiment), specifically the North Atlantic overturning rate determination and to the JGOFS project (Joint Global Ocean Flux Study). During the second and third legs, M 26/2 and M 26/3, the research programs served the Sonderforschungsbereich 313 (Environmental Change in the northern North Atlantic) as well as those of two European Community projects SEEP (Gas and Water Seepage on the European Continental Margin) and ENAM (European North Atlantic Margin). Other projects, addressing the well-known cold water carbonates of the Norwegian Sea (Boreale Flachwasserkarbonate) and the history of post-glacial rebound of the Scandinavian shield (Hebungsgeschichte Skandinaviens), were also part of M 26.
AN: 3680303
74 of 200
TI: Joint Global Ocean Flux Study: The 1989 North Atlantic Bloom Experiment
AU: Ducklow,-H.W.
AF: Horn Point Environ. Lab., Univ. Maryland Cent. Environ. Estuar. Stud., Box 775, Cambridge, MD 21613, USA
SO: OCEANOGRAPHY 1989 vol. 2, no. 1, pp. 4-8
LA: English
ER: M (Marine)
AB: In 1989, JGOFS begins a six-nation, eight month investigation of biogeochemical processes in the North Atlantic Ocean. This experiment will emphasize observation of the spring phytoplankton bloom and its biogeochemical consequences along longitude 20 degree W, between 15 degree and 60 degree N latitude, from March to October. The North Atlantic Bloom Experiment is intended to be a pilot study for future JGOFS experiments. (DBO)
AN: 3663176
75 of 200
TI: Carbon-cycle imbalances in the Sargasso Sea
AU: Michaels,-A.F.; Bates,-N.R.; Buesseler,-K.O.; Carlson,-C.A.; Knap,-A.H.
AF: Bermuda Biol. Stn. Res., Ferry Reach GEO1, Bermuda
SO: NATURE 1994 vol. 372, no. 6506, pp. 537-539
LA: English
ER: M (Marine)
AB: The net exchange of carbon dioxide between the atmosphere and the ocean, and thus the nature of the oceanic carbon sink, is dominated by the seasonal dynamics of carbon cycling in the upper ocean. This cycle represents a balance between abiotic and biotic carbon transport into, and export out of, the ocean's upper layer. Here we report measurements of these processes made over five years in the Sargasso Sea off Bermuda, as part of the US Joint Global Ocean Flux Study (JGOFS). We find that the decreases in carbon stocks from the spring to the autumn in the upper 150 m of the ocean is three times larger than the measured sum of biotic and abiotic fluxes out of this layer. This discrepancy can be explained either by failure to account for horizontal advection of carbon or by inaccuracies in the fluxes of sinking particles as measured using sediment traps. Either the traps miss 80% of the sinking particles, or 70% of the carbon cycling is due to advection (or a combination of both processes is responsible). Sediment-trap measurements of the super(234)Th flux during this period suggest that most of the discrepancy may be due to inaccuracies in the trap methods, which would require a very general reassessment of existing ideas about particle export and remineralization of carbon in the oceans. If, on the other hand, advection is the main source of the discrepancy, the traditional one-dimensional (vertical) modeling of the oceanic carbon cycle cannot give a full account of carbon dynamics.
AN: 3656175
76 of 200
TI: Specific variability in Fe-enriched cultures from the equatorial Pacific
AU: Fryxell,-G.A.; Kaczmarska,-I.
AF: Dep. Oceanogr., Texas A&M Univ., College Station, TX 77843-3146, USA
SO: J.-PLANKTON-RES. 1994 vol. 16, no. 7, pp. 775-769
LA: English
ER: M (Marine)
AB: Water collected on the spring equatorial Pacific Joint Global Ocean Flux Study (JGOFS) was placed in ultra-clean bottles in an incubator on deck under the direction of the team of J.H. Martin. Half of bottles were enriched with 2.53 mM iron; the other half served as controls. Cell counts increased, while the number of species was reduced, in both the controls and the treated samples over the period of the experiment. Diatoms dominated, and after an early growth spurt in the Fe-enriched bottles, most diatom species showed greater growth in the controls at the end of the 6 day experiment. However, as the experiment was terminated, more cells overall were noted in the Fe-enrich samples, with the most abundant diatom, Cylindotheca closterium, principally responsible for the difference. Growth rates were high in both the controls and the treated samples, with overall rates of 1.3-3.0 divisions/day in the Fe-treated samples and 1.9-3.4 divisions/day in the controls. The group of smaller pennate diatoms averaged 2.9 divisions/day in the Fe-treated samples and 3.3 divisions/day in the controls over the entire experiment.
AN: 3653764
77 of 200
TI: Towards a joint global ocean flux study: Rationale, objectives, planning, implementation
AU: De-Baar,-H.J.W.; Van-Aken,-H.M.; Fransz,-H.G.; Ganssen,-G.M.; Gieskes,-W.W.C.
CA: Nederlands Inst. voor Onderzoek der Zee, Texel (Netherlands)
SO: 1988 59 pp
NT: NTIS Order No.: PB91-142901/GAR.
RN: NIOZ-1988-14 (NIOZ198814)
LA: English
ER: M (Marine)
AB: The oceanic inventories and fluxes of carbon are of major importance for the global C cycle in past, present and future. The global scale of the problem and the intricate interactions between physical, biological, and chemical forces warrant both an international and a truly multidisciplinary approach. Objective of the ICSU/SCOR/JGOFS program is 'To determine and understand on a global scale the time varying fluxes of carbon and associated biogenic elements in the ocean, and to evaluate the related exchanges with the atmosphere, the sea floor and continental boundaries'. Planning for 1989-1999 is focusing on (1) Process studies in selected areas; (2) Time Series observations to be continued or newly started; (3) Global Survey largely through satellite observation. The merits of selected study areas in regions as the Antarctic Ocean, the Pacific Basin, the Northwest Indian Ocean and the North Atlantic Ocean are being exploited. Implementation is now well underway with the North Atlantic Pilot Study where ships from six countries participate in a study of the temporal and spatial shifts of C fluxes related to the spring and autumn plankton blooms. (DBO)
AN: 3651499
78 of 200
TI: Variability of water masses and of organic production-regeneration systems as related to eutrophic, mesotrophic and oligotrophic conditions in the Northeast Atlantic Ocean
AU: Pierre,-C.; Vangriesheim,-A.; Laube-Lenfant,-E.
AF: LODYC, Univ. Pierre et Marie Curie, Paris, France
SO: J.-MAR.-SYST. 1994 vol. 5, no. 2, pp. 159-170
LA: English
ER: M (Marine)
AB: In the eastern part of the tropical North Atlantic, the trade winds generate a permanent coastal upwelling system along West Africa. Eutrophic conditions resulting from the uplift of nutrient-rich deep waters are progressively dissipated westwards. The Eumeli 2 cruise (January-February 1991) realized in the framework of the France-JGOFS program, gave the opportunity to study the internal variability of the water column at three typical sites, eutrophic, mesotrophic and oligotrophic, located near 20 degree N of latitude. The hydrological survey at each site provides a description of the different water layers. The mixed surface layer of variable thickness at the three sites covers the Central Waters; North Atlantic Central Water and South Atlantic Central Water are competing along the Cape Verde Frontal Zone which crosses the mesotrophic and eutrophic zones. Underneath, the Antarctic Intermediate Water and the North Atlantic Deep Water correspond respectively to minimum and maximum salinities. The oxygen and carbon stable isotope compositions of these identified water masses bring complementary geochemical informations, such as the carbon cycling through production-regeneration. In surface and central waters, the partial differential super(18)O of water and salinities vary linearly with a slope of 0.46, typical of tropical oceanic areas. The major changes of partial differential super(13)C of sigma CO sub(2) occur in the upper 900 m. From oligotrophic to eutrophic conditions, the surficial partial differential super(13)C values decrease by about 1ppt; the lowest partial differential super(13)C values which mark the level of maximum regeneration rate are reached very close to the surface at the eutrophic site (at about 50 to 100 m), and deeper at the mesotrophic and oligotrophic sites (respectively at about 200 m and 500 m). The NADW appears as a very homogeneous water layer, with almost constant partial differential super(18)O and partial differential super(13)C values at the three sites, implying that organic matter remineralization occurs at too slow rate at depth to introduce detectable amounts of super(13)C-depleted CO sub(2).
AN: 3650778
79 of 200
TI: Nannoplankton and protozoan microzooplankton during the JGOFS North Atlantic Bloom Experiment: 1989 and 1990
AU: Stoecker,-D.K.; Sieracki,-M.E.; Verity,-P.G.; Michaels,-A.E.; Haugen,-E.; Burkill,-P.; Edwards,-E.S.
AF: Horn Point Environ. Lab., P.O. Box 775, Cambridge, MD 21613, USA
SO: J.-MAR.-BIOL.-ASSOC.-U.K. 1994 vol. 74, no. 2, pp. 427-443
LA: English
ER: M (Marine)
AB: Complex mesoscale eddy interactions are characteristic of the North Atlantic, resulting in a mosaic of water masses with different physical, chemical and biological properties. Observations of protist assemblages during spring 1989 and 1990 in the vicinity of 47 degree N 18 degree W indicate that timing, composition, and further development of the spring bloom community are highly variable between years. During 1989 a microbial community, dominated by small photosynthetic nanoplankton and protist grazers, was observed after the main diatom bloom in the transition zone between two cyclonic eddies. This community was characterized by a high ratio of 'protozoan' to 'phytoplankton' carbon, and dominance of the microzooplankton by mixotrophic ciliates. A nanodiatom/prymnesiophyte bloom was observed to replace the typical 'microdiatom' bloom in a front between a cyclonic and anticyclonic eddy during 1990. After the demise of the diatoms, high standing stocks of nanophytoplankton persisted until early June. In this post-diatom-bloom period, the 'protozoan' biomass was lower and the 'nanophytoplankton' stocks higher than in 1989. Very high stocks of heterotrophic nanodinoflagellates were observed in 1990. The factors responsible for the development of these quite different microbial food-webs in two consecutive years and the consequences thereof for ecosystem function remain to be more fully explored.
AN: 3650756
80 of 200
TI: Modeling of the sedimentation of marine particles in laminar flow. Application to the continental margin
AU: Gorand,-D.; Monaco,-A.
AF: Lab. Mar. Sedimentol. and Geochem., CNRS, URA 715, Univ. Perpignan, France
SO: J.-MAR.-SYST. 1994 vol. 4, no. 6, pp. 441-452
LA: English
ER: M (Marine)
AB: In the present paper we propose an initial stage of modeling of the sedimentation of marine particles in the water-column, excluding the turbulence and the surficial water layer from 0 to 100 m. This marine sedimentation depends on several parameters: the mass concentration of particles, their density and diameters, the water temperature and salinity, the currents, etc... In order to compare the general tendences foreseen by the model and those revealed by experiment, we use experimental data obtained in the southwestern margin of the Gulf of Lions in the Northwestern Mediterranean in the framework of the ECOMARGE programme (France-JGOFS).
AN: 3632463
81 of 200
TI: Phytoplankton and primary production characteristics at selected sites in the geostrophic Almeria-Oran front system (SW Mediterranean Sea)
AU: Videau,-C.; Sournia,-A.; Prieur,-L.; Fiala,-M.
AF: Univ. Bretagne Occidentale, c/o: Lab. Biomembranes, Ec. Norm. Super.; 46, rue d'Ulm, 75231 Paris cedex 05, France
SO: J.-MAR.-SYST. 1994 vol. 5, no. 3-5, pp. 235-250
LA: English
ER: M (Marine)
AB: Several phytoplankton-related characteristics were measured at six selected sites of the frontal system of the Alboran Sea during May 1991 ("Almofront-1" cruise, JGofs-France). As compared to the surrounding oligotrophic waters, the frontal jet exhibited higher (though moderate) diatom abundance, higher nannoplankton abundance, higher chlorophyll content and higher primary production. Flow cytometry and fractionated filtration indicated the predominance of the smaller phytoplankton size classes, except on the right border of the jet. In the frontal area, the deep chlorophyll maximum (DCM) reached up to 2 mu g chl. a/1 and extended over a 50-meter thickness with a frequent subdivision into two maxima. Photosynthesis/irradiance curves measured in surface and in deeper water were strikingly different in the oligotrophic sites and similar or identical in the frontal sites, suggesting different hydrodynamic patterns. Application of the Falkowski' model resulted in displacement times of about 1-2 d between the surface and DCM in the frontal jet, and isopycnal transport of about 10 cm/s. Altogether, phytoplankton data (size and species composition, chlorophyll content, production and photosynthetic tests) as well as isopycnals and nitracline slopes, are consistent with other data collected during "Almofront-1" as regards (1) a front-induced nutrient enrichment and (2) a subsequent downwelling of plant biomass. Although the (geostrophic) Almeria-Oran front is basically a permanent one, seasonal and shorter-scale temporal variations must be taken into account.
AN: 3631052
82 of 200
TI: Zooplankton biomass, feeding and metabolism in a geostrophic frontal area (Almeria-Oran Front, western Mediterranean). Significance to pelagic food webs
AU: Thibault,-D.; Gaudy,-R.; Le-Fevre,-J.
AF: Stn. Mar. Endoume, Cent. Oceanol. Marseille, rue Batterie des Lions, F-1300 Marseille, France
SO: J.-MAR.-SYST. 1994 vol. 5, no. 3-5, pp. 297-311
LA: English
ER: M (Marine)
AB: Mesozooplankton abundance and physiological rates in copepods were measured at selected sites in the Alboran Sea, in May 1991, on Cruise Almofront 1 (JGofs-France). Higher total zooplankton standing stocks, higher copepod abundance, higher feeding activity by the latter and a higher proportion of phytoplankton-derived carbohydrates in their diet were found in the geostrophic jet of inflowing Atlantic water than in surrounding areas, which offered a range of oligotrophic conditions. Relationships with data obtained in other disciplinary fields on the same cruise show that biological enrichment was due to locally enhanced production rather than advection of exogenous living matter. In the most productive context, sustained production effected by phytoplankton cells in the > 10 mu m class size (diatoms) was being significantly transferred to higher trophic levels through herbivores with a relatively long generation time (copepods). The processes responsible for the fertilization, and their relationship to the jet and its frontal boundary, are discussed.
AN: 3631049
83 of 200
TI: Automated in situ observations of upper ocean biogeochemistry, bio-optics, and physics and their potential use for global studies
AU: Dickey,-T.D.; Granata,-T.C.; Taupier-Ietage,-I.
CA: University of Southern California, Los Angeles (USA)
SO: 1992 37 pp
LA: English
ER: M (Marine)
AB: The process controlling the flux of carbon in the upper ocean have dynamic ranges in space and time of at least nine orders of magnitude. These processes depend on a broad suite of inter-related biogeochemical, bio-optical, and physical variables. These variables should be sampled on scales matching the relevant phenomena. Traditional ship-based sampling, while critical for detailed and more comprehensive observations, can span only limited portions of these ranges because of logistical and financial constraints. Further, remote observations from satellite platforms enable broad horizontal coverage which is restricted to the upper few meters of the ocean. For these main reasons, automated subsurface measurement systems are important for the fulfillment of research goals related to the regional and global estimation and modeling of time varying biogeochemical fluxes. Within the past few years, new sensors and systems capable of autonomously measuring several of the critical variables have been developed. The platforms for deploying these systems now include moorings and drifters and it is likely that autonomous underwater vehicles (AUV's) will become available for use in the future. Each of these platforms satisfies particular sampling needs and can be used to complement both shipboard and satellite observations. In the present review, (1) sampling considerations will be summarized, (2) examples of data obtained from some of the existing automated in situ sampling systems will be highlighted, (3) future sensors and systems will be discussed, (4) data management issues for present and future automated systems will be considered, and (5) the status of near real-time data telemetry will be outlined. Finally, we wish to make it clear at the outset that the perspectives presented here are those of the authors and are not intended to represent those of the United States JGOFS program, the International JGOFS program, NOAA's C&GC program, or other global ocean programs.
AN: 3605132
84 of 200
TI: Role of the ocean in climate changes
AU: Gulev,-S.K.
CA: State Oceanographic Inst., Moscow (Russia). Hydrometeorology Comm.
SO: 1992 14 pp
LA: English
ER: M (Marine)
AB: The present program aimed at the study of ocean climate change is prepared by a group of scientists from State Oceanographic Institute, Academy of Science of Russia, Academy of Science of Ukraine and Moscow State University. It appears to be a natural evolution of ideas and achievements that have been developed under natural and international ocean research projects such as SECTIONS, WOCE, TOGA, JGOFS and others. The two primary goals are set in the program ROCC (1) Quantitative description of the global interoceanic "conveyor" and it's role in formation of the large scale anomalies in the North Atlantic. The objectives on the way to this goal are: to get the reliable estimates of year-to-year variations of heat and water exchange between the Atlantic Ocean and the atmosphere; to establish and understand the physics of long period variations in meridianal heat and fresh water transport (MHT and MFWT) in the Atlantic Ocean; to analyze the general mechanisms, that form the MHT and MFWT in low latitudes (Ekman flux), middle latitudes (western boundary currents) and high latitudes (deep convection) of the North Atlantic; to establish and to give quantitative description of the realization of global changes in SST, surface salinity, sea level and sea ice data. (2) Development of the observational system pointed at tracing the climate changes in the North Atlantic. This goal merges the following objectives: to find the proper sites that form the inter annual variations of MHT; to study the deep circulation in the "key" points; to develop the circulation models reflecting the principle features of interoceanic circulation; and to define global and local response of the atmosphere circulation to large scale processes in the Atlantic Ocean.
AN: 3605107
85 of 200
TI: Ocean time-series near Bermuda: Hydrostation S and the US JGOFS Bermuda Atlantic time-series study
AU: Michaels,-A.F.; Knap,-A.H.
SO: 1992 21 pp
LA: English
ER: M (Marine)
AB: Bermuda is the site of two ocean time-series programs. At Hydrostation S, the ongoing biweekly profiles of-temperature, salinity and oxygen now span 37 years. This is one of the longest open-ocean time-series data sets and provides a view of decadal scale variability in ocean processes. In 1988, the U.S. JGOFS Bermuda Atlantic Time-series Study began a wide range of measurements at a frequency of 14-18 cruises each year to understand temporal variability in ocean biogeochemistry. On each cruise, the data range from chemical analyses of discrete water samples to data from electronic packages of hydrographic and optics sensors. In addition, a range of biological and geochemical rate measurements are conducted that integrate over time-periods of minutes to days. This sampling strategy yields a reasonable resolution of the major seasonal patterns and of decadal scale variability. The Sargasso Sea also has a variety of episodic production events on scales of days to weeks and these are only poorly resolved. In addition, there is a substantial amount of mesoscale variability in this region and some of the perceived temporal patterns are caused by the intersection of the biweekly sampling with the natural spatial variability. In the Bermuda time-series programs, we have added a series of additional cruises to begin to assess these other sources of variation and their impacts on the interpretation of the main time-series record. However, the adequate resolution of higher frequency temporal patterns will probably require the introduction of new sampling strategies and some emerging technologies such as biogeochemical moorings and autonomous underwater vehicles.
AN: 3605040
86 of 200
TI: JGOFS North Atlantic bloom experiment: An overview
AU: Ducklow,-H.W.
CA: Maryland Univ., Cambridge (USA). Horn Point Environmental Labs.
SO: 1992 23 pp
LA: English
ER: M (Marine)
AB: The North Atlantic Bloom Experiment (NABE) of JGOFS presents a unique opportunity and challenge to the data management community because of the diversity and large size of biogeochemical data sets collected. NABE was a pilot study for JGOFS and has also served as a pilot study within the U.S. NODC for management and archiving of the data sets. Here I present an overview to some of the scientific results of NABE, which will be published as an Introduction to a special volume of NABE results in Deep-Sea Research later this year. An overview of NABE data management is given elsewhere in the present report. This is the first collection of papers from the Joint Global Ocean Flux Study (JGOFS). Formed as an international program in 1987, JGOFS has four principal elements: modelling and data management, multidisciplinary regional process studies, a global survey of biogeochemical properties and long-term time series observatories. In 1989-1990 JGOFS conducted a pilot process study of the spring phytoplankton bloom the North Atlantic Bloom Experiment (NABE). JGOFS decided to conduct a large scale, internationally-coordinated pilot study in the North Atlantic because of its proximity to the founding nations of the project, the size and predictability of the bloom and its fundamental impact on ocean bio-geochemistry (Billett et al., 1983; Watson and Whitfield, 1985; Pfannkuche, 1992). In 1989, six research vessels from Canada, Germany. The Netherlands, the United Kingdom and the USA and over 200 scientists and students from more than a dozen nations participated in NABE. Some of their initial results are reported in this volume.
AN: 3605033
87 of 200
TI: Data management for community research projects: A JGOFS case study
AU: Lowry,-R.K.
CA: Proudman Oceanographic Lab., Bidston (UK)
SO: 1992 23 pp
LA: English
ER: M (Marine)
AB: Since the mid 1980s, much of the marine science research effort in the United Kingdom has been focused into large scale collaborative projects involving public sector laboratories and university departments, termed Community Research Projects. Two of these, the Biogeochemical Ocean Flux Study (BOFS) and the North Sea Project incorporated large scale data collection to underpin multidisciplinary modeling efforts. The challenge of providing project data sets to support the science was met by a small team within the British Oceanographic Data Center (BODC) operating as a topical data center. The role of the data center was to both work up the data from the ship's sensors and to combine these data with sample measurements into online databases. The working up of the data was achieved by a unique symbiosis between data center staff and project scientists. The project management, programming and data processing skills of the data center were combined with the oceanographic experience of the project communities to develop a system which has produced quality controlled, calibrated data sets from 49 research cruises in 3.5 years of operation. The data center resources required to achieve this were modest and far outweighed by the time liberated in the scientific community by the removal of the data processing burden. Two online project databases have been assembled containing a very high proportion of the data collected. As these are under the control of BODC their long term availability as part of the UK national data archive is assured. The success of the topical data center model for UK Community Research Project data management has been founded upon the strong working relationships forged between the data center and project scientists. These can only be established by frequent personal contact and hence the relatively small size of the UK has been a critical factor. However, projects covering a larger, even international scale could be successfully supported by a network of topical data centers managing online databases which are interconnected by object oriented distributed data management systems over wide area networks.
AN: 3605014
88 of 200
TI: Data management for JGOFS: Theory and design
AU: Flierl,-G.R.; Bishop,-J.K.B.; Glover,-D.M.; Paranjpe,-S.
CA: Massachusetts Inst. of Technology, Cambridge (USA)
SO: pp. 229-249,
LA: English
ER: M (Marine)
AB: The Joint Global Ocean Flux Study (JGOFS), currently being organized under the auspices of the Scientific Committee for Ocean Research (SCOR), is intended to be a decade long internationally coordinated program. The main goal of JGOFS is to determine and understand on a global scale the processes controlling the time-varying fluxes of carbon and associated biogenic elements in the ocean and to evaluate the related exchanges with the atmosphere, sea floor and continental boundaries. "A long-term goal of JGOFS will be to establish strategies for observing, on long time scales, changes in ocean biogeochemical cycles in relation to climate change". Participation from a large number of U.S. and foreign institutions is expected. JGOFS investigators have begun a set of time-series measurements and global surveys of a wide variety of biological, chemical and physical quantities, detailed process-oriented studies, satellite observations of ocean color and wind stress and modeling of the biogeochemical processes. These experiments will generate data in amounts unprecedented in the biological and chemical communities; rapid and effortless exchange of these data will be important to the success of JGOFS.
AN: 3601553
89 of 200
TI: Observations on the pelagic system in the Tropical Atlantic at 20 degree N (The EUMELI Program)
AU: Jacques,-G.
AF: Obs. Oceanol., 66650 Banyuls-sur-mer, France
CO: JGOFS -- France, Paris (France), 14 Nov 1991
SO: OCEAN-FLUXES-STUDY:-AN-OVERVIEW-ABOUT-JGOFS-FRANCE-PROGRAM,-INSU,-PARIS,-NOVEMBER-14,-1991. Jacques,-G.;Sournia,-A.;Buart-Menard,-P.;Morel,-A.;Monaco,-A.;Andersen,-V.-eds. PARIS-FRANCE INSTITUT-OCEANOGRAPHIQUE 1993 vol. 69, no. 1 pp. 9-14
ST: ANN.-INST.-OCEANOGR.-PARIS-NOUV.-SER. vol. 69, no. 1
LA: English
ER: M (Marine)
AB: Research during the Eumeli Program aimed at comparing primary production and the vertical flux in an oligotrophic regime with that of a mesotrophic site, in order to design a model of the functioning of the system to serve in the interpretation of future satellite data. Preliminary results reinforce the concept of new production-regenerated production, the greatest part of photosynthesised carbon (low level of production < 50 g C m super(-2) y super(-1)) being rapidly recycled in the superficial layer. By comparing the oligotrophic and the mesotrophic sites, the following ratios were obtained: chlorophyll biomass = 1/2; total production ( super(14)C) = 1/3; exported flux = 1/7; flux arriving in deep waters = 1/15.
AN: 3592753
90 of 200
TI: Spectrofluorometric analysis of photosynthetic pigments in the Gulf of Lions (Mediterranean Sea) with an emphasis on the autotrophic picoplankton
AU: Lantoine,-F.; Neveux,-J.
AF: Obs. Oceanol., 66650 Banyuls-sur-Mer, France
CO: JGOFS -- France, Paris (France), 14 Nov 1991
SO: OCEAN-FLUXES-STUDY:-AN-OVERVIEW-ABOUT-JGOFS-FRANCE-PROGRAM,-INSU,-PARIS,-NOVEMBER-14,-1991. Jacques,-G.;Sournia,-A.;Buart-Menard,-P.;Morel,-A.;Monaco,-A.;Andersen,-V.-eds. PARIS-FRANCE INSTITUT-OCEANOGRAPHIQUE 1993 vol. 69, no. 1 pp. 173-176
ST: ANN.-INST.-OCEANOGR.-PARIS-NOUV.-SER. vol. 69, no. 1
LA: English
ER: M (Marine)
AB: Regular monthly sampling of the autotrophic picoplankton was undertaken (March 1991-March 1993) on a transect, in the Gulf of Lions. Spectrofluorometric analysis of pigment composition was done. Three main groups were distinguished within the picoplankton community: the prochlorophytes, cyanobacteria, and picoeukaryotes.
AN: 3592750
91 of 200
TI: Vertical distributions and migrations of macrozooplankton and micronekton in the Ligurian Sea (NW Mediterranean)
AU: Andersen,-V.; Sardou,-J.; Nival,-P.
AF: Stn. Zool., Obs. Oceanol. Villefranche, URA CNRS 716, B.P. 28, 06230 Villefranche-sur-Mer, France
CO: JGOFS -- France, Paris (France), 14 Nov 1991
SO: OCEAN-FLUXES-STUDY:-AN-OVERVIEW-ABOUT-JGOFS-FRANCE-PROGRAM,-INSU,-PARIS,-NOVEMBER-14,-1991. Jacques,-G.;Sournia,-A.;Buart-Menard,-P.;Morel,-A.;Monaco,-A.;Andersen,-V.-eds. PARIS-FRANCE INSTITUT-OCEANOGRAPHIQUE 1993 vol. 69, no. 1 pp. 129-132
ST: ANN.-INST.-OCEANOGR.-PARIS-NOUV.-SER. vol. 69, no. 1
LA: English
ER: M (Marine)
AB: In order to appreciate the influence of macroplanktonic and micronektonic migrants and help in the calibration and improvement of mathematical models, several cruises (MigZoo) were planned in the Ligurian Sea during which an offshore location Dyfamed station (43 degree 24'N, 7 degree 52'E) was sampled. The series of oblique and horizontal hauls made in May 1990 enabled the analysis of vertical distributions of nine species of micronekton and five species of gelatinous macroplankton. The fourteen species described here fall into four main categories: strong and synchronous migrations; asynchronous or disorderly migrations; weak migration; and non-migration.
AN: 3592744
92 of 200
TI: Evolution of Cd, Pb, Zn concentrations in the Ligurian Sea since 1983
AU: Nicolas,-E.
AF: Lab. Phys. et Chim. Mar., Obs. Oceanol. Villefranche, B.P. 08, 06230 Villefranche-sur-Mer, France
CO: JGOFS -- France, Paris (France), 14 Nov 1991
SO: OCEAN-FLUXES-STUDY:-AN-OVERVIEW-ABOUT-JGOFS-FRANCE-PROGRAM,-INSU,-PARIS,-NOVEMBER-14,-1991. Jacques,-G.;Sournia,-A.;Buart-Menard,-P.;Morel,-A.;Monaco,-A.;Andersen,-V.-eds. PARIS-FRANCE INSTITUT-OCEANOGRAPHIQUE 1993 vol. 69, no. 1 pp. 119-122
ST: ANN.-INST.-OCEANOGR.-PARIS-NOUV.-SER. vol. 69, no. 1
LA: English
ER: M (Marine)
AB: Six vertical profiles of Cd, Pb, Zn were established at the Dyfamed station between June 1987 and January 1991. These results were compared with those obtained in 1983 at a station located in the same area in order to discover whether changes in trace-metal distributions in the Ligurian Sea had occurred during this period, due to the evolution of anthropogenic emissions.
AN: 3592742
93 of 200
TI: Dissolved organic carbon (DOC) in the NW Mediterranean sea (use of the high temperature method)
AU: Copin-Montegut,-G.; Avril,-B.
AF: Lab. Phys. et Chim. Mar., Obs. Oceanol. Villefranche, B.P. 08, 06230 Villefranche-sur-Mer, France
CO: JGOFS -- France, Paris (France), 14 Nov 1991
SO: OCEAN-FLUXES-STUDY:-AN-OVERVIEW-ABOUT-JGOFS-FRANCE-PROGRAM,-INSU,-PARIS,-NOVEMBER-14,-1991. Jacques,-G.;Sournia,-A.;Buart-Menard,-P.;Morel,-A.;Monaco,-A.;Andersen,-V.-eds. PARIS-FRANCE INSTITUT-OCEANOGRAPHIQUE 1993 vol. 69, no. 1 pp. 123-124
ST: ANN.-INST.-OCEANOGR.-PARIS-NOUV.-SER. vol. 69, no. 1
LA: English
ER: M (Marine)
AB: In 1991 and 1992, a series of cruises (Papadoc) at Dyfamed station 1 allowed us to obtain detailed vertical profiles of dissolved organic carbon (COC). In the 150-2000 m layer, DOC distribution was uniform, with a content of about 0.7 mg C l super(-1). In surface waters, DOC concentration changed according to the hydrological situation and the primary production cycle: during February, waters were DOC-homogeneous through the whole water column, but this was followed by an increased concentration lasting until the end of summertime.
AN: 3592738
94 of 200
TI: Ocean Fluxes Study: An overview about JGOFS-France Program, INSU, Paris, November 14, 1991
AU: Jacques,-G.; Sournia,-A.; Buart-Menard,-P.; Morel,-A.; Monaco,-A.; Andersen,-V.-(eds.)
AF: Obs. Oceanol., 66650 Banyuls-sur-mer, France
CO: JGOFS-France, Paris (France), 4 Nov 1991
SO: ANN.-INST.-OCEANOGR.-PARIS-NOUV.-SER. PARIS-FRANCE INSTITUT-OCEANOGRAPHIQUE 1993 vol. 69, no. 1, pp. 9-201
LA: English
ER: M (Marine)
AN: 3592734
95 of 200
TI: Production of non-methane hydrocarbons by seawater
AU: Bonsang,-B.; Polle,-C.; Lambert,-G.
AF: Cent. Faibl. Radioact., 91198 Gif-sur-Yvette Cedex, France
CO: JGOFS -- France, Paris (France), 14 Nov 1991
SO: OCEAN-FLUXES-STUDY:-AN-OVERVIEW-ABOUT-JGOFS-FRANCE-PROGRAM,-INSU,-PARIS,-NOVEMBER-14,-1991. Jacques,-G.;Sournia,-A.;Buart-Menard,-P.;Morel,-A.;Monaco,-A.;Andersen,-V.-eds. PARIS-FRANCE INSTITUT-OCEANOGRAPHIQUE 1993 vol. 69, no. 1 pp. 125-128
ST: ANN.-INST.-OCEANOGR.-PARIS-NOUV.-SER. vol. 69, no. 1
LA: English
ER: M (Marine)
AB: Non-methane hydrocarbons (NMHC) influence the budget of tropospheric ozone and play a fundamental role in the oxidizing capacity of the atmosphere. Superficial seawater, supersaturated in light non-methane hydrocarbons by two or three orders of magnitude, acts as a net source for the atmosphere. Their composition is characterized by a high proportion of alkenes, mainly ethene and propene. The vertical distribution of NMHC with depth shows the existence of maximum concentrations in the euphotic layer for most of the light C2-C6 NMHC. Three different kind of species have a typical distribution: acetylene, light C2-C5 alkenes and alkanes. Isoprene is identified for the first time in seawater.
AN: 3592730
96 of 200
TI: Hydrography and suspended particle transport in the Gulf of Lions
AU: Nyffeler,-F.
AF: Groupe Oceane, Inst. Geol., 11 Rue Emile Argand, Neuchatel, Switzerland
CO: JGOFS -- France, Paris (France), 14 Nov 1991
SO: OCEAN-FLUXES-STUDY:-AN-OVERVIEW-ABOUT-JGOFS-FRANCE-PROGRAM,-INSU,-PARIS,-NOVEMBER-14,-1991. Jacques,-G.;Sournia,-A.;Buart-Menard,-P.;Morel,-A.;Monaco,-A.;Andersen,-V.-eds. PARIS-FRANCE INSTITUT-OCEANOGRAPHIQUE 1993 vol. 69, no. 1 pp. 137-140
ST: ANN.-INST.-OCEANOGR.-PARIS-NOUV.-SER. vol. 69, no. 1
LA: English
ER: M (Marine)
AB: Hydrographic and nephelometric surveys of the Gulf of Lions margin were carried out between September 1986 and May 1988. Their aim was to localize the main sources of suspended matter on the margin, to identify the processes responsible for its subsequent dispersion and to establish a global mass budget for the particulate matter. The results illustrate the importance of lateral transport along the canyons, in the evaluation of fluxes of suspended matter, mainly due to small slowly settling particles.
AN: 3592726
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TI: Organic input and transformation at the water-sediment interface of the NW Mediterranean slope (Gulf of Lions)
AU: Buscail,-R.; Guidi-Guilvard,-L.
AF: Lab. Sedimentol. et Geochim. Mar., URA CNRS 715, Univ. Perpignan, 66860 Perpignan Cedex, France
CO: JGOFS -- France, Paris (France), 14 Nov 1991
SO: OCEAN-FLUXES-STUDY:-AN-OVERVIEW-ABOUT-JGOFS-FRANCE-PROGRAM,-INSU,-PARIS,-NOVEMBER-14,-1991. Jacques,-G.;Sournia,-A.;Buart-Menard,-P.;Morel,-A.;Monaco,-A.;Andersen,-V.-eds. PARIS-FRANCE INSTITUT-OCEANOGRAPHIQUE 1993 vol. 69, no. 1 pp. 147-154
ST: ANN.-INST.-OCEANOGR.-PARIS-NOUV.-SER. vol. 69, no. 1
LA: English
ER: M (Marine)
AB: Near-bottom fluxes of organic matter were studied in the northwestern Mediterranean continental slope (sediment traps were deployed at a depth of about 1000 m in two canyons and one open slope). We found that fluxes of organic matter increase from the east to the west and were subjected to seasonal variations. Near-bottom organic material being different from that of the upper deposits, the geochemical and biological responses of sediment interfaces were studied at the same time and locations. The results emphasize the need for direct evaluations of the flux parameters at the SWI. For this purpose, an input of organic matter was simulated and followed over time in the different biotic and abiotic compartments of the SWI.
AN: 3592722
98 of 200
TI: Biogenic particle transfer on the NW Mediterranean continental margin: A summary of ECOMARGE results
AU: Heussner,-S.; Monaco,-A.; Carbonne,-J.
AF: Lab. Sedimentol. et Geochim. Mar., Univ. Perpignan, URA CNRS 715, 66860 Perpignan Cedex, France
CO: JGOFS -- France, Paris (France), 14 Nov 1991
SO: OCEAN-FLUXES-STUDY:-AN-OVERVIEW-ABOUT-JGOFS-FRANCE-PROGRAM,-INSU,-PARIS,-NOVEMBER-14,-1991. Jacques,-G.;Sournia,-A.;Buart-Menard,-P.;Morel,-A.;Monaco,-A.;Andersen,-V.-eds. PARIS-FRANCE INSTITUT-OCEANOGRAPHIQUE 1993 vol. 69, no. 1 pp. 141-146
ST: ANN.-INST.-OCEANOGR.-PARIS-NOUV.-SER. vol. 69, no. 1
LA: English
ER: M (Marine)
AB: In the northwestern Mediterranean advection plays a prominent role in the transfer of matter and energy on continental margins. During winter and spring, lithogenic fluxes cumulate with biogenic fluxes and rapidly reach the slope sediments. Organic carbon evolution with depth enables two functional types of margins to be defined: an oceanic margin, characterized by a decreasing flux, and a continental margin, where the flux increasing with depth indicates carbon advection from adjacent regions. A close coupling exists between spatial and temporal variabilities of the particulate fluxes and those of benthic activities.
AN: 3592720
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TI: Sedimentological and biogeochemical characteristics of surficial sediments in the Cap-Ferret Canyon (France)
AU: Cremer,-M.; Weber,-O.; Relexans,-J.C.; Beliard,-M.; Etcheber,-H.; Jouanneau,-J.-M.
AF: Dep. Geol. et Oceanogr., Ave. Facultes, 33405 Talence, Cedex, France
CO: JGOFS -- France, Paris (France), 14 Nov 1991
SO: OCEAN-FLUXES-STUDY:-AN-OVERVIEW-ABOUT-JGOFS-FRANCE-PROGRAM,-INSU,-PARIS,-NOVEMBER-14,-1991. Jacques,-G.;Sournia,-A.;Buart-Menard,-P.;Morel,-A.;Monaco,-A.;Andersen,-V.-eds. PARIS-FRANCE INSTITUT-OCEANOGRAPHIQUE 1993 vol. 69, no. 1 pp. 161-166
ST: ANN.-INST.-OCEANOGR.-PARIS-NOUV.-SER. vol. 69, no. 1
LA: English
ER: M (Marine)
AB: A survey has been conducted in the Cap-Ferret Canyon area (Bay of Biscay) in order to study the role played by the continental margin in the transfer of material from the continent to the deep-ocean (Ecomarge Program). Sedimentological (grain-size, CaCO sub(3) content) and biogeochemical (Mn, particulate organic carbon, O sub(2) consumption, ETS) parameters were measured on surficial sediment (uppermost 1 cm).
AN: 3592678
100 of 200
TI: Importance of organic colloids in estuarine waters and continental margin (high temperature catalytic oxidation)
AU: Sempere,-R.; Charriere,-B.; Cauwet,-G.
AF: Dep. Chem., Fac. Sci., Tokyo Univ., 1-1 Minami-Ohsawa, Hachioji-shi, 192 03 Tokyo, Japan
CO: JGOFS -- France, Paris (France), 14 Nov 1991
SO: OCEAN-FLUXES-STUDY:-AN-OVERVIEW-ABOUT-JGOFS-FRANCE-PROGRAM,-INSU,-PARIS,-NOVEMBER-14,-1991. Jacques,-G.;Sournia,-A.;Buart-Menard,-P.;Morel,-A.;Monaco,-A.;Andersen,-V.-eds. PARIS-FRANCE INSTITUT-OCEANOGRAPHIQUE 1993 vol. 69, no. 1 pp. 167-172
ST: ANN.-INST.-OCEANOGR.-PARIS-NOUV.-SER. vol. 69, no. 1
LA: English
ER: M (Marine)
AB: We studied organic colloids in estuarine waters and continental margin of Rhone delta. Total organic carbon (TOC) was arbitrarily divided into three fractions: particulate organic carbon (POC) colloidal organic carbon (COC), truly dissolved organic carbon (tDOC). Most of the organic stock in the bottom layer is in a particulate and colloidal state, while the truly dissolved fraction is dominant in the marine environment. This phenomenon, associated with constants values of tDOC, suggests that COC could easily be degradable by bacterial activity in such a system. The high values of the organic stock observed near the bottom, could be explained by lateral advection from the continental slope.
AN: 3592672
101 of 200
TI: Quantitative approach of bioturbation on continental margin
AU: Gerino,-M.; Stora,-G.; Gontier,-G.; Weber,-O.
AF: Cent. Oceanol. Marseille, Stn. Mar. Endoume, Rue la Batterie des Lions, 13007 Marseille, France
CO: JGOFS -- France, Paris (France), 14 Nov 1991
SO: OCEAN-FLUXES-STUDY:-AN-OVERVIEW-ABOUT-JGOFS-FRANCE-PROGRAM,-INSU,-PARIS,-NOVEMBER-14,-1991. Jacques,-G.;Sournia,-A.;Buart-Menard,-P.;Morel,-A.;Monaco,-A.;Andersen,-V.-eds. PARIS-FRANCE INSTITUT-OCEANOGRAPHIQUE 1993 vol. 69, no. 1 pp. 177-182
ST: ANN.-INST.-OCEANOGR.-PARIS-NOUV.-SER. vol. 69, no. 1
LA: English
ER: M (Marine)
AB: Research in the framework of the Ecomarge operation was carried out on the Mediterranean and Atlantic continental margins to quantify the bioturbation processes. These studies aim: to identify and quantify the responsible organisms (macrobenthos); to determine and measure the processes generated by these organisms in the sedimentary column, such as biogenic structures (resin casts of burrows) and sediment mixing (introduction of a tracer at the surface of the sediment); to provide evidence of the incidence of bioturbation on solute flux through the sediment-water interface; and to modelise these phenomena.
AN: 3592668
102 of 200
TI: The modelling operation of the JGOFS-France program. Aims and description
AU: Rabouille,-C.; Andersen,-V.
AF: Cent. Faibl. Radioact., CNRS-CEA, 91198 Gif-sur-Yvette, France
CO: JGOFS -- France, Paris (France), 14 Nov 1991
SO: OCEAN-FLUXES-STUDY:-AN-OVERVIEW-ABOUT-JGOFS-FRANCE-PROGRAM,-INSU,-PARIS,-NOVEMBER-14,-1991. Jacques,-G.;Sournia,-A.;Buart-Menard,-P.;Morel,-A.;Monaco,-A.;Andersen,-V.-eds. PARIS-FRANCE INSTITUT-OCEANOGRAPHIQUE 1993 vol. 69, no. 1 pp. 197-202
ST: ANN.-INST.-OCEANOGR.-PARIS-NOUV.-SER. vol. 69, no. 1
LA: English
ER: M (Marine)
AB: The aim of the modelling operation in the JGOFS-France program, which is to build a general model linking the euphotic layer processes to the sediment-water interface processes, is briefly introduced. The different submodels concerning the euphotic zone, the water column and the sedimentary environment, with their locations of application are described. A positive evaluation of our action has been made, although further studies on the water column are needed, as well as the development of 3D modelling.
AN: 3592666
103 of 200
TI: NE Atlantic continental margin (ECOFER) suspended material and primary production
AU: Madron,-X.D.-de; Etcheber,-H.; Froidefond,-J.M.; Godet,-C.H.; Jouanneau,-J.-M.; Laborde,-P.; Nyffeler,-F.; Ruch,-P.; Urrutia,-J.; Valencia,-V.; Weber,-O.
AF: Groupe Oceane, Inst. Geol., 11 rue Emile Argand, Neuchatel, Switzerland
CO: JGOFS -- France, Paris (France), 14 Nov 1991
SO: OCEAN-FLUXES-STUDY:-AN-OVERVIEW-ABOUT-JGOFS-FRANCE-PROGRAM,-INSU,-PARIS,-NOVEMBER-14,-1991. Jacques,-G.;Sournia,-A.;Buart-Menard,-P.;Morel,-A.;Monaco,-A.;Andersen,-V.-eds. PARIS-FRANCE INSTITUT-OCEANOGRAPHIQUE 1993 vol. 69, no. 1 pp. 155-160
ST: ANN.-INST.-OCEANOGR.-PARIS-NOUV.-SER. vol. 69, no. 1
LA: English
ER: M (Marine)
AB: AVHRR/NOAA-II satellite data of the Biscay Bay were processed to obtain the sea surface temperatures and the turbidity index at the surface of the sea, from the coast to the continental slope. A comparison with ship data is obtained during the Gastel-1 survey. Nephelometric and pigment profiles were carried out.
AN: 3592664
104 of 200
TI: Fluorescence of continental and marine waters
AU: Donard,-O.F.X.; De-Souza-Sierra,-M.M.; Belin,-C.; Ewald,-M.; Amouroux,-D.; Etcheber,-H.
AF: Lab. Photophys. Photochim. Mol., Univ. Bordeaux I, 33045 Talence Cedex, France
CO: JGOFS -- France, Paris (France), 14 Nov 1991
SO: OCEAN-FLUXES-STUDY:-AN-OVERVIEW-ABOUT-JGOFS-FRANCE-PROGRAM,-INSU,-PARIS,-NOVEMBER-14,-1991. Jacques,-G.;Sournia,-A.;Buart-Menard,-P.;Morel,-A.;Monaco,-A.;Andersen,-V.-eds. PARIS-FRANCE INSTITUT-OCEANOGRAPHIQUE 1993 vol. 69, no. 1 pp. 189-192
ST: ANN.-INST.-OCEANOGR.-PARIS-NOUV.-SER. vol. 69, no. 1
LA: English
ER: M (Marine)
AB: Fully corrected fluorescent emission and excitation spectra recorded in estuarine, coastal and marine waters (Ecomarge program) have revealed two distinct pools of dissolved fluorescent material. Photophysical properties of fluorescent organic matter confirm the differences observed between coastal and marine waters.
AN: 3592656
105 of 200
TI: In situ observation of flocs in natural waters
AU: Courp,-T.; Eisma,-D.; Kalf,-J.
AF: Lab. Sedimentol. et Geochim. Mar., Univ. Perpignan, 66860 Perpignan Cedex, France
CO: JGOFS -- France, Paris (France), 14 Nov 1991
SO: OCEAN-FLUXES-STUDY:-AN-OVERVIEW-ABOUT-JGOFS-FRANCE-PROGRAM,-INSU,-PARIS,-NOVEMBER-14,-1991. Jacques,-G.;Sournia,-A.;Buart-Menard,-P.;Morel,-A.;Monaco,-A.;Andersen,-V.-eds. PARIS-FRANCE INSTITUT-OCEANOGRAPHIQUE 1993 vol. 69, no. 1 pp. 183-188
ST: ANN.-INST.-OCEANOGR.-PARIS-NOUV.-SER. vol. 69, no. 1
LA: English
ER: M (Marine)
AB: In situ distribution and particle size of suspended matter were measured in two sites (the Mediterranean Pyrenean margin and the Gironde Estuary, Bay of Biscay) using an in situ suspension camera designed at the Netherlands Institute for Sea Research, Texel. The camera system is described. It can be used in any waters down to 4000 m depth and in water with a suspended matter concentration up to 200 mg dm super(-3).
AN: 3592654
106 of 200
TI: Gd deletion in particulate matter from the water column
AU: Thomas,-B.; Donard,-O.F.X.; Grousset,-F.; Heussner,-S.; Carbonne,-J.; Monaco,-A.
AF: Lab. Photophys. Mol., Univ. Bordeaux I, 33405 Talence Cedex, France
CO: JGOFS -- France, Paris (France), 14 Nov 1991
SO: OCEAN-FLUXES-STUDY:-AN-OVERVIEW-ABOUT-JGOFS-FRANCE-PROGRAM,-INSU,-PARIS,-NOVEMBER-14,-1991. Jacques,-G.;Sournia,-A.;Buart-Menard,-P.;Morel,-A.;Monaco,-A.;Andersen,-V.-eds. PARIS-FRANCE INSTITUT-OCEANOGRAPHIQUE 1993 vol. 69, no. 1 pp. 193-197
ST: ANN.-INST.-OCEANOGR.-PARIS-NOUV.-SER. vol. 69, no. 1
LA: English
ER: M (Marine)
AB: A negative anomaly of gadolinium has been detected in Suspended particulate matter from the water column in the Bay of Biscay. Two hypotheses are presented to explain particulate depletion in these water masses.
AN: 3592653
107 of 200
TI: Dissolved organic carbon in oligotrophic waters: Experiments on sample preservation, storage and analysis
AU: Tupas,-L.M.; Popp,-B.N.; Karl,-D.M.
AF: Sch. Ocean and Earth Sci. and Technol., Univ. Hawaii, 1000 Pope Road, Honolulu, HI 96822, USA
SO: MAR.-CHEM. 1994 pp. 207-216
LA: English
ER: M (Marine)
AB: Different methods of preservation and storage of samples for analysis of abundance of dissolved organic carbon (DOC) in oligotrophic waters were evaluated and compared to shipboard measurements. DOC concentrations in samples stored frozen (-20 degree C) in acid-cleaned polypropylene tubes, high-density polyethylene bottles, and combusted glass ampoules, even for extended periods (up to 5 months after collection), were indistinguishable from those measured on ship at the time of collection. Addition of phosphoric acid (0.025% H sub(3)PO sub(4) final concentration in seawater) was necessary to preserve samples at 4 degree C. Filtration prior to storage was not necessary for the oligotrophic ocean samples analyzed in this study. Removal of dissolved inorganic carbon can be accomplished by bubbling with either high-purity nitrogen or oxygen with no effects on DOC abundance measurements. An estimate of the analytical blank was determined by injecting distilled water which was exposed to high-intensity ultraviolet light, acidified and purged with nitrogen to remove inorganic carbon. The analytical blank measured in this study was 18.7 plus or minus 1.5 mu m C for a 100 mu l injection volume. This value was applied as the minimum correction to DOC abundance measurements of seawater. Using the methods described in this paper we observed DOC concentrations of approximately 90-115 mu M C for the upper 50 m of the water column at the US-JGOFS Station Aloha (22 degree 45'N, 158 degree W). DOC concentrations decreased with depth to concentrations of approximately 50 mu M C at 500 m and remained relatively constant at greater depths.
AN: 3582670
108 of 200
TI: EqPac: A process study in the Central Equatorial Pacific
AU: Murray,-J.W.; Leinen,-M.W.; Feely,-R.A.; Toggweiler,-J.R.; Wanninkhof,-R.
AF: Sch. Oceanogr., Univ. Washington, Seattle, WA 98195, USA
SO: OCEANOGRAPHY 1992 vol. 5, no. 3, pp. 134-142
LA: English
ER: M (Marine)
AB: EqPac is the United States-Joint Global Ocean Flux Study (US-JGOFS) process study in the central equatorial Pacific. The first EqPac cruises sailed in January 1992 during a moderately strong El Nino. This was fortuitous for our studies of chemical and biological distributions because El Nino events are difficult to predict, and the lead time for a project of this size is long. There was virtually no previous upper-water-column chemical or biological data for El Nino conditions in the central equatorial Pacific. Now an El Nino has been studied in considerable detail, and it will be easy to sample the extremes in environmental conditions by sampling non-El Nino conditions (including La Nina) in 1993 and the years thereafter. The implementation of EqPac illustrates how difficult it is to mount a large-scale interdisciplinary study of the ocean when the interannual variability is large.
AN: 3580280
109 of 200
TI: Role of the oceans in the global CO sub(2) balance: The 23rd voyage of the R/V Vityaz, 16 August to 14 November 1991
AU: Vinogradov,-M.Ye.
AF: Shirshov Inst. Oceanol., Russian Acad. Sci., Moscow, Russia
SO: OCEANOL.-ACAD.-SCI.-USSR 1992 vol. 32, no. 3, pp. 413-415
LA: English
ER: M (Marine)
AB: The 23rd voyage of the R/V Vityaz' from 16 Aug to 14 Nov 1991 was concerned with the northern Atlantic (7 Sep to 2 Nov) and the Black Sea (16-23 Aug and 7-12 Nov). The main task was to examine the global carbon cycle in accordance with the JGOFS international program focusing on the carbon flux from the atmosphere through the euphotic production zone into deep layers. A major form of man's influence on the environment is the discharge of CO sub(2), which produces the greenhouse effect, and which can result in undesirable climatic changes. The oceans are the most important regulator of CO sub(2) in the atmospheres because there is a biological pump, in which dissolved CO sub(2) is used to make organic matter by a photosynthesis and in the formation of the skeletons of many animals from CaCO sub(3), so the CO sub(2) concentration in the water tends to fall, which increases the dissolution of atmospheric CO sub(2). The organic carbon formed by biosynthesis partially reenters the solution as a result of destruction, but it is partly preserved in sediments and thus is withdrawn from the global cycle for a long period. Another task was to monitor ecosystem states in open parts of the Black Sea, where there have been catastrophic changes in recent years on account of various man-made effects, mainly on account of mass development of a new inhabitant, the predatory Ctenophore Mneniopsis. The structure deformation in the open Black Sea ecosystem is increasing from year to year, and the stocks of food zooplankton are decreasing. There is a need to estimate the biomass of this Ctenophore and its behavior in order to forecast the subsequent effects on the Black Sea ecosystem and the reduction in the fish productivity.
AN: 3565250
110 of 200
TI: Biogeochemical interactions in the Equatorial Pacific
AU: Barber,-R.T.; Murray,-J.W.,Jr.; McCarthy,-J.J.
AF: Duke Univ., Sch. Environ., Mar. Lab., 111 Pivers Island Rd., Beaufort, NC 28516-9721, USA
SO: AMBIO 1994 vol. 23, no. 1, pp. 62-66
LA: English
ER: M (Marine)
AB: During 1992, the Joint Global ocean Flux Study (JGOFS) investigated biogeochemical fluxes in the central equatorial Pacific Ocean. The equatorial pacific is the largest natural source of atmospheric carbon dioxide, but the magnitude of the flux varies interannually with the El Nino-Southern Oscillation cycle. Sediments beneath the equatorial upwelling are enriched in organic carbon indicating a strong export flux, but contemporary new primary production is lower than expected given the relative concentrations of new nutrients. The multidisciplinary JGOFS research plan was designed to address apparent contradictions in this system, and to assess the roles of equatorial physical and biological processes in regulating the ocean-atmosphere exchange of carbon.
AN: 3557067
111 of 200
TI: The internal consistency of CO sub(2) measurements in the Equatorial Pacific
AU: Millero,-F.J.; Byrne,-R.H.; Wanninkhof,-R.; Feely,-R.; Clayton,-T.; Murphy,-P.; Lamb,-M.F.
AF: Rosenstiel Sch. Mar. and Atmos. Sci., Univ. Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA
SO: MAR.-CHEM. 1993 vol. 44, no. 2-4, pp. 269-280
LA: English
ER: M (Marine)
AB: During a recent NOAA JGOFS Equatorial Pacific cruise all four analytical parameters of the carbonate system were measured-pH, total alkalinity (TA), total carbon dioxide (TCO sub(2)), and the fugacity of carbon dioxide (fCO sub(2)). The measurements made during leg 2 on surface waters have been used to examine the internal consistency of the carbon dioxide system in these waters. The internal consistency of the measurements was examined by using various inputs of the measured parameters (pH-TA, pH-TCO sub(2), pH-fCO sub(2)-TA, fCO sub(2)-TA, fCO sub(2)-TCO sub(2) and TA-TCO sub(2)) to calculate the components of the CO sub(2) system. The results indicate that the measurements have an internal consistency of plus or minus 0.003-0.006 in pH, plus or minus 5-7 mu mol/kg in TA, plus or minus 5-7 mu mol/kg in TCO sub(2) and plus or minus 6-9 mu Atm in fCO sub(2) if reliable constants are used for the dissociation of carbonic acid in seawater. These results indicate that our present understanding of the thermodynamics of the carbonate system in seawater is close to the present accuracy in measuring the various parameters of the system ( plus or minus 0.002 in pH, plus or minus 4 mu mol/kg in TA, plus or minus 2 mu mol/kg in TCO sub(2) and plus or minus 2 mu Atm in fCO sub(2)).
AN: 3536790
112 of 200
TI: Titration alkalinity of seawater
AU: Millero,-F.J.; Zhang,-J.; Lee,-K.; Campbell,-D.M.
AF: Rosenstiel Sch. Mar. and Atmos. Sci., Univ. Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA
SO: MAR.-CHEM. 1993 vol. 44, no. 2-4, pp. 153-165
LA: English
ER: M (Marine)
AB: The titration system is described that was used to measure the total alkalinity of seawater (TA) during the Joint Global Ocean Flux Study (JGOFS) sponsored by the National Oceanic and Atmospheric Administration (NOAA) in the equatorial Pacific. It consists of a piston titrator, a pH meter, and a glass thermostated cell. Since the new pH meters and titrators have RS232 interfaces the system can be easily connected to a personal computer. The computer programs used to carry out the titration and to determine TA, pH sub(SW) (pH on the seawater scale), and TCO sub(2) from the full titration curve are described. A typical titration takes 20 min and consists of 25 points. Six separate titration cells were calibrated to be used on three systems at sea. The reliability of the electrodes was examined by titrations of 0.7 m NaCl with HCl at a pH near 3 and using seawater buffers at a pH near 8. Although most electrodes did not have Nernstian behavior over the entire pH range, all gave precise values of TA for a given solution. The individual cells were calibrated using standard Na sub(2)CO sub(3) and seawater standards prepared in our laboratory and Certified Reference Material (CRM) provided by Dickson. The cells gave reliable values of TA, but the values of pH sub(SW) were low (0.02) and values of TCO sub(2) were high (20 mu mol/kg) due to the non-Nernstian behavior of the electrodes at a pH near 8.0. If the slope determined from the buffers is used, the titrations yield reliable values of TA, TCO sub(2) and pH sub(SW). Measurements on Dickson standards with the three cells at sea indicate that the systems have a reproducibility of plus or minus 2-4 mu mol/kg in TA. The titration values of TCO sub(2) determined on the CRMs and the samples collected at sea were about 17 plus or minus 6 mu mol/kg (fall) and 20 plus or minus 6 mu mol/kg (spring) too high. This offset in TCO sub(2) is independent of depth and is due to the non-Nernstian behavior of the electrodes. The offset is not due to unknown protolytes.
AN: 3536780
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TI: WOCE South Atlantic 1992 Cruise No. 22, 22 September 1992 - 31 January 1993
AU: Siedler,-G.; Balzer,-W.; Mueller,-T.; Onken,-R.; Rhein,-M.; Zenk,-W.-(eds.)
SO: METEOR-BER. HAMBURG-FRG LEITSTELLE-METEOR.-INST.-FUER-MEERESKUNDE 1993 no. 93-5, 131 pp
LA: English
ER: M (Marine)
AB: From 22 September 1992 to 31 January 1993 the German Research Vessel METEOR performed its 22nd cruise, a journey in the Atlantic Ocean divided into five legs. The main objectives were geological and chemical observations in subtropical regions of the North Atlantic and in the tropical South Atlantic. Additional physical investigations were concentrated in the equatorial regions and at subtropical latitudes of the South Atlantic. These activities were coordinated internationally as part of the World Ocean Circulation Experiment (WOCE). They were supplemented by biological and air chemistry observations and by a component of Joint Global Ocean Flux Study (JGOFS). The present cruise report contains a summary of the research objectives and includes cruise narratives and tentative observational results. The report also includes extended tables on all stations occupied. The cruise was funded by the Deutsche Forschungsgemeinschaft and the Bundesministerium fuer Forschung und Technologie.
AN: 3536675
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TI: [North Atlantic 92 Cruise No. 21, 16 March - 31 August 1992.]
OT: Nordatlantik 92 Reise Nr. 21, 16. Maerz - 31. August 1992
AU: Pfannkuche,-O.; Duinker,-J.C.; Graf,-G.; Henrich,-R.; Thiel,-H.; Zeitzschel,-B.-(eds.)
SO: METEOR-BER. HAMBURG-FRG LEITSTELLE-METEOR.-INST.-FUER-MEERESKUNDE 1993 no. 93-4, 281 pp
LA: German
ER: M (Marine)
AB: The 21 super(st) expedition of RV METEOR led into the eastern North Atlantic. Research was carried out between Madeira and the Svalbard Archipelago. The expedition was divided into 6 legs. The main objective on four legs which concentrated on the area between Madeira and Iceland was the investigation of the oceanic flux of greenhouse gases. The investigations carried out by the German groups of the Joint Global Ocean Flux Study (JGOFS) will provide data for the creation and verification of models for climatic changes. Physical, chemical, and biological investigations were concentrated to a transect along 20 degree W and to a time series station in the BIOTRANS area at 47 degree N, 20 degree W. The investigations focussed on the fluxes of greenhouse gases between the ocean's upper mixed layer and the atmosphere, the chemical and biological carbon dioxide fixation on the cycling of carbon in the epipelagial as well as the flux of sedimented particulate organic carbon in the deep-sea benthic boundary zone. Two legs were restricted to investigations in the Norwegian, Greenland and Barents Sea. The programmes were carried out by the Sonderforschungsbereich 313 of the Kiel University. Apart from investigations on the vertical particle flux influenced by pelagic processes, station work focussed on studies of the lateral particle transport, on processes in the bottom near nepheloid layer, and on fluxes in the benthic boundary layer. On the basis of already available data on recent sediment formation processes and partly in analogy with these investigations, it is intended to reconstruct the history of the marine environment.
AN: 3536674
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TI: Sediment trap fluxes of polycyclic aromatic hydrocarbons in the Mediterranean Sea
AU: Lipiatou,-E.; Marty,-J.-C.*; Saliot,-A.
AF: Lab. Phys. Chim. Mar., Obs. Oceanol. Villefranche, UA CNRS 353, Quai de la Darse, BP 8, 06230 Villefranche-sur-Mer, France
SO: MAR.-CHEM. 1993 vol. 44, no. 1, pp. 43-54
LA: English
ER: M (Marine)
AB: Fluxes of polycyclic aromatic hydrocarbons (PAHs) were measured in the Ligurian Sea (northwestern Mediterranean Sea) in sediment trap experiments, from the DYFAMED operation (France/JGOFS program). PAH fluxes, from 0.30 to 0.91 mu g m super(-2)/d, were compared to those calculated from PAH concentrations in zooplankton fecal pellets collected in the same area and in Mediterranean surface sediments. The distribution of PAH and ratio of specific compound in sediment traps suggested that the PAH mixture has a predominantly pyrolytic origin from anthropic combustion processes. Phenanthrene, fluoranthene and pyrene were generally the major compounds in both sediment traps and fecal pellets. The transport pathways for these PAHs were different than for the higher molecular weight compounds (compounds with more than 4 rings). The low molecular weight PAH fluxes were larger in the water column than in surface sediment; fluxes for the higher molecular weight compounds were similar in both compartments. The difference in fluxes is discussed in terms of composition, transport and recycling of PAHs in different reservoirs.
AN: 3534013
116 of 200
TI: Factors controlling bioturbation in deep-sea sediments and their relation to models of carbon diagenesis
AU: Smith,-C.R.
AF: Dep. Oceanogr., Univ. Hawaii at Manoa, 1000 Pope Rd. Honolulu, HI 96822 USA
CO: NATO Advanced Research Workshop, College Station, TX (USA), 2-6 Apr 1991
SO: DEEP-SEA-FOOD-CHAINS-AND-THE-GLOBAL-CARBON-CYCLE. Rowe,-G.T.;Pariente,-V.-eds. DORDRECHT-NETHERLANDS KLUWER-ACADEMIC-PUBLISHERS 1992 vol. 360 pp. 375-393
ST: NATO-ASI-SER.-SER.-C:-MATH.-PHYS.-SCI. vol. 360
LA: English
ER: M (Marine)
AB: I review the processes controlling particle mixing in sediments at water depths greater than 1000 m, and discuss variations in these processes on a variety of space and time scales. In addition, I outline impacts of these variations on seafloor models of particulate-organic carbon (POC) diagenesis. Recent literature and scaling arguments suggest that deposit feeding typically controls the biological mixing of near-shore, and presumably, deep-sea sediments. Resultant bioturbation rates vary dramatically with particle quality; small and/or recently sedimented particles can be mixed at least 10 times faster than larger and/or older sediment grains. This variability requires careful selection of mixing tracers for use in modeling studies of organic-carbon diagenesis. Bioturbation in at least one deep-sea site (the Santa Catalina Basin) is highly variable on horizontal scales of meters due to the activities of megabenthos; scaling arguments suggest megabenthos may be similarly important to mixing in many deep-sea sediments. At the regional scale, a community-level synthesis suggests there are strong positive correlations between seafloor POC flux and bioturbation. In particular, an equation relating faunal body size, abundance, and sediment POC content predicts a greater than or equal to 10-fold decline in bioturbation rates, for a given tracer, along the JGOFS equatorial Pacific transect (from 0 to 10 degree N along 140 degree W) and the VERTEX transect (from the California slope to the North Pacific gyre); these predictions are in agreement with limited existing super(210)Pb data. Finally, I suggest that seasonal pulses of phytodetritus, such as observed in the temperate North Atlantic, may have large (and spatially patchy) positive and negative effects on deep-sea bioturbation rates. Seasonal studies of bioturbation are necessary to elucidate the impacts of such detrital pulses on POC and biomarker burial at the ocean floor.
AN: 3531318
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TI: How do microbial communities keep living in the Mediterranean outflow within Northeast Atlantic intermediate waters?
AU: Savenkoff,-C.; Lefevre,-D.; Denis,-M.*; Lambert,-C.E.
AF: Cent. Oceanol. Marseille, URA, CNRS 41, Parc Sci. Technol. Luminy, Case 901, F13288 Marseille Cedex 9, France
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 627-641
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: As part of the France-JGOFS programme, the Mediterranean outflow within the Atlantic Ocean was investigated during MEDATLANTE cruises (January and August 1989). The present work is focused on the export and fate into the Atlantic of the microbial communities carried away from the Mediterranean Sea by this outflow that generates Meddies (Mediterranean eddies). The respiratory activity of micro-organisms ( less than or equal to 200 mu m) was monitored through their electron transport system (ETS) activity in Meddy "Nicole" (36 degree 25'N, 10 degree 35'W), Meddy "Yseult" (36 degree 20'N, 16 degree W), and in waters of Mediterranean origin (MOW) at 36 degree 57'N, 17 degree 02'W. On each cruise, profiles of ETS activity through the water column (0-2000 m) were established in the Mediterranean Sea to serve as a reference for the ETS activity profiles in the Atlantic. ETS activity within the Meddies or MOW was similar to that in the Mediterranean Sea at the same period and significantly higher (up to three times) than that calculated for intermediate Atlantic waters. Within investigated Meddies and MOW, rates of metabolic CO sub(2) production varied from 64.8 mg C/m super(2)/day (Meddy Nicole) to 200.5 mg C/m super(2)/day (Meddy Yseult). This represents up to 10 times the rate of metabolic CO sub(2) production within the corresponding 500-1500 m layer in the Sargasso Sea.
AN: 3530701
118 of 200
TI: Growth and fluorescence characteristics of ultraplankton on a north-south transect in the eastern North Atlantic
AU: Veldhuis,-M.J.W.; Kraay,-G.W.; Gieskes,-W.W.C.
AF: Netherlands Inst. Sea Res., P.O. Box 59, 1790 AB Den Burg, Texel, Netherlands
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 609-626
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: In the summer of 1989 vertical profiles of chlorophyll a were taken in the North Atlantic. Stations were located along a transect following longitude 20 degree W, between 60 and 33 degree N. Maximum chlorophyll a levels were located near the surface in the north but became gradually deeper towards the south. Primary production varied only by a factor of 2.3 (226-533 mg C/m super(2)/day), whereas the assimilation ratio showed far less variation (15.46 plus or minus 4.61 mg C/mg Chl/day, n = 14). The northern part of the transect showed no thermal stratification, and nutrients were plentiful. Phytoplankton was distributed homogeneously, with a nearly constant signature of the cellular fluorescence characteristics as monitored by flow-cytometry. The dominant taxa were small prymnesiophytes (Emiliania huxleyi) and chroococcoid phycoerythrin-containing cyanobacteria. Cells were healthy, resulting in net growth rates (growth rate minus grazing) of up to 0.75 divisions per day. Of the total primary production, 68% was actually converted into new plant carbon. Midway along the transect (47 degree N) there was a sharp thermocline at a depth of 35 m. All nutrients (nitrogen, phosphate and silicate) were depleted in the upper water layer. Cyanobacteria dominated the phytoplankton community in numbers varying from 12,000 to 39,000 cells/ml. Stabilization of the water column was apparently in progress, as could be derived from the gradual increase in mean cellular red fluorescence of the cyanobacteria with depth.
AN: 3530700
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TI: Annual biogenic particle fluxes to the interior of the North Atlantic Ocean; studied at 34 degree N 21 degree W and 48 degree N 21 degree W
AU: Honjo,-S.; Manganini,-S.J.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02453, USA
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 587-607
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: In order to clarify the annual quality, quantity and export process of biogenic particles from the euphotic zone to the deep ocean interior, an array of automated time-series sediment traps were deployed for 1 year from 4 April 1989 to 17 April 1990 at 34 degree N 21 degree W and 48 degree N 21 degree W as part of the Joint Global Ocean Flux Program (JGOFS) North Atlantic Bloom Experiment (NABE). Three sediment traps with 13 time-series sediment collectors were placed at both stations approximately 1 and 2 km below the surface and 0.7 km above the bottom. They collected settling particles during 26 14-day intervals for 376 days with an 20-day hiatus in September-October 1989 for changeover of the trap moorings. The collection periods of the six traps were synchronized, forming a spatio-temporal matrix of 156 samples. The annual mass flux at about 2 km deep during this experiment was 22 and 27 g/m super(2)/y at the 34 and 48 degree N stations, consisting of biogenic particles with traceable quantities of lithogenic particle flux. The spring particle bloom, characterized by the sedimentation of particles relatively enriched by N sub(org), began in January at the 34 degree N station and in March at the 48 degree N station. The bloom continued for 4.5 and 3 months and provided 62 and 50% of the annual biogenic particle mass flux at 2 km at the 34 and 48 degree N stations. The surface bloom penetrated to the ocean interior within a few weeks, with apparently accelerated settling speed at deeper layers. The order of susceptibility of biogenic elements to mineralization while settling in the 1-0.7 km a.b. water column was, from least to most resistant: P, N sub(org), C sub(org), Si and Ca. The C/N/P ratio at 0.7 km a.b. was 154 : 18 : 1 at the 34 degree N station and 148 : 18 : 1 at the 48 degree N station.
AN: 3530699
120 of 200
TI: The role of plankton in particle flux: Two case studies from the Northeast Atlantic
AU: Passow,-U.; Peinert,-R.
AF: Mar. Sci. Inst., Univ. California, Santa Barbara, CA 93106-6150, USA
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 573-585
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: The relationship between the vertical flux of microplankton and its standing stock in the upper ocean was determined in the subtropical (33 degree N, 21 degree W) and tropical (18 degree N, 30 degree W) northeast Atlantic in spring 1989 as part of the North Atlantic Bloom Experiment. In the subtropical area specific sedimentation rates at all depths were low (0.1% of standing stock) and 10-20% of settled particulate organic carbon (POC) was viable diatoms. The high contribution of viable diatoms, their empty frustules and tintinnid loricae to settled material characterized a system in transition between a diatom bloom sedimentation event and an oligotrophic summer situation. In the tropical area specific sedimentation rates were similar, but absolute rates (3 mg C/m super(2)/day) were only about a third of those in the subtropical area. Microplankton carbon contributed only 2-6% to POC. Hard parts of heterotrophs found embedded in amorphous detrital matter suggest that particles had passed through a complex food web prior to sedimentation. Coccolithophorids, not diatoms dominated the autotrophic fraction in traps, and a shift in the composition of autotrophs may indicate a perturbation of the oligotrophic system.
AN: 3530698
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TI: Mesozooplankton standing stock during the North Atlantic spring bloom study in 1989 and its potential grazing pressure on phytoplankton: A comparison between low, medium and high latitudes
AU: Lenz,-J.; Morales,-A.; Gunkel,-J.
AF: Inst. Meereskd., Univ. Kiel, Duesternbrooker Weg 20, 2300 Kiel 1, FRG
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 559-572
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: Within the framework of the JGOFS Pilot Study in 1989 mesozooplankton (0.2-20 mm) was sampled by means of a Hydro-Bios multinet in five depth strata (0-25, 25-50, 50-100, 100-200, 200-500 m) during four Lagrangian drift experiments of 8-14 days' duration at 18, 33, 46 and 58 degree N, to follow the seasonal progress of the phytoplankton spring bloom development in the northeast Atlantic. Mesozooplankton standing stock, measured as dry weight and ash-free dry weight, increased by a factor of about 6 from 18 to 58 degree N. Day/night differences amounted to 10-20% of the average and were-with one exception at 18 degree N-not statistically significant. Using the data on weight-specific respiration rates measured by colleagues on the same cruise, the ingestion rates and potential community grazing of mesozooplankton on phytoplankton within the upper 100 m of the water column were calculated. During all four drift experiments, quasi-steady-state conditions were observed in phyto- and zooplankton standing stock, primary production and daily sedimentation at 100 m depth. The maximum potential grazing rate by mesozooplankton accounted for about half of the daily primary production. Since sedimentation of fresh phytoplankton was negligible, it is concluded that the grazing pressure exercised by mesozooplankton together with micro- and nanozooplankton was responsible for keeping the phytoplankton standing stock at a more or less constant level during the investigated spring bloom in the four areas. Particle flux was thus dominated by zooplankton faecal material.
AN: 3530697
122 of 200
TI: The Nose: A characteristic inversion within the salinity maximum water in the tropical Northeast Atlantic
AU: Podewski,-S.; Saure,-G.; Eppley,-R.W.; Koeve,-W.; Peinert,-R.; Zeitzschel,-B.
AF: Inst. Meereskd., Univ. Kiel, Duesternbrooker Weg 20, 2300 Kiel 1, FRG
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 537-557
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: During leg 1 of Meteor cruise 10 in March/April 1989 at 18 degree N, 30 degree W, the high spatial and temporal resolution of hydrographic CTD-stations indicated that the study site was in a hydrographically complex region in the transition zone between the Canary Current and the North Equatorial Current at the southern boundary of the subtropical gyre. Strong variability was found within the upper 120 m due to interleavings of warmer and saltier subtropical salinity maximum water with colder and less saline upper thermocline water. The interleavings caused unexpected nose-like temperature, salinity, nitrate and oxygen profiles yet not described in the literature. A second variability source was found in the Central Water area, because the study area was situated in the vicinity of the Central Water Boundary dividing North and South Atlantic Central Water. Hydrographic analysis of the study shows that interpretations of biological and chemical data can only be done in conjunction with high resolution CTD-profiling.
AN: 3530696
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TI: An unexpected nitrate distribution in the Tropical North Atlantic at 18 degree N, 30 degree W -- implications for new production
AU: Koeve,-W.; Eppley,-R.W.; Podewski,-S.; Zeitzschel,-B.
AF: Inst. Meereskd., Univ. Kiel, Duesternbrooker Weg 20, 2300 Kiel 1, FRG
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 521-536
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: During a R.V. Meteor JGOFS-NABE cruise to a tropical site in the northeast Atlantic in spring 1989, three different vertical regimes with respect to nitrate distribution and availability within the euphotic zone were observed. Besides dramatic variations in the depth of the nitracline, a previously undescribed nose-like nitrate maximum within the euphotic zone was the most prominent feature during this study. Both the vertical structure of phytoplankton biomass and the degree of absolute and relative new production were related to the depth of the nitracline, which in turn was dependent on the occurrence/non-occurrence of the subsurface subtropical salinity maximum (S sub(max)). The mesoscale variability of the nitracline depth, as indicated from a pre-survey grid, and published data on the frequent occurrence of the S sub(max) in tropical waters suggest higher variability of new production and F-ratio than usually expected for oligotrophic oceans. The importance of salt fingering and double diffusion for nitrate transport into the euphotic zone is discussed.
AN: 3530695
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TI: Productivity regime and phytoplankton size structure in the tropical and subtropical North Atlantic in spring 1989
AU: Jochem,-F.J.; Zeitzschel,-B.
AF: Inst. Meereskd., Univ. Kiel, Duesternbrooker Weg 20, 2300 Kiel 1, FRG
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 495-519
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: Productivity regime and phytoplankton size structure are described for two different epipelagic systems in the tropical/subtropical Northeast Atlantic Ocean investigated during 9-11 day drift studies in spring 1989 in the JGOFS North Atlantic Bloom Experiment, 18 degree N, 30 degree W and 33 degree N, 20 degree W. At the 18 degree N study site, an oligotrophic system was encountered. The water column above the main pycnocline at about 50-60 m depth was nutrient-depleted, and both chlorophyll and primary production displayed subsurface maxima at the nutricline. Picoplankton was the dominant size fraction, accounting for 78-90% of chlorophyll and 83-98% of primary production. Synechococcus-type coccoid cyanobacteria were the dominant picoplankters. The hydrographic situation was characterized by high small-scale variability; the most interesting feature was the intrusion of nutrient-depleted Subtropical Salinity Maximum Water into the euphotic zone, whose impacts on the productivity regime are discussed. At 33 degree N study site, a post-bloom situation was encountered. Although the euphotic zone was nutrient-depleted, higher amounts of larger phytoplankton were present, the contribution of picoplankton being 42-53% of chlorophyll and 42-86% of primary production. Over the course of the drift study, subsurface maxima of chlorophyll and productivity evolved, the contribution of picoplankton having increased. Picocyanobacteria again were the dominant picoplankters. At both study sites the profiles of abundance ratios of picocyanobacteria to picoeucaryotes cell numbers proved to be a useful tool to characterize water masses.
AN: 3530694
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TI: Microzooplankton and their herbivorous activity in the northeastern Atlantic Ocean
AU: Burkill,-P.H.; Edwards,-E.S.; John,-A.W.G.; Sleigh,-M.A.
AF: Plymouth Mar. Lab., Prospect Place, Plymouth PL1 3DH, UK
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 479-493
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: Microzooplankton and their herbivorous activity were studied at four stations between 60 and 47 degree N along the 20 degree W meridian in mid-summer, as part of the 1989 U.K. Biogeochemical Ocean Flux Study. Microzooplankton were abundant in the surface mixed layer at all stations, with concentrations ranging between 2000 and 14,000 organisms. The community was dominated by Protozoa, which contributed >98% of the numerical abundance of microzooplankton and >80% of their standing stocks. Three families of Protozoa-the Strombidiidae (Ciliophora: Oligotrichida), Gymnodiniidae and Peridiniidae (both Sarcomastigophora: Dinoflagellida)-dominated the microzooplankton, contributing >70% of the standing stocks. Microzooplankton standing stocks within the mixed layer showed a distinct latitudinal gradient that varied between 6.5 and 9.8 mu gC/l at 60 and 47 degree N, respectively. When integrated over the mixed layer depth, microzooplankton standing stocks ranged between 300 and 428 mgC m super(-2) at 47 and 60 degree N, respectively. Microzooplankton standing stocks were approximately one-quarter to one-third that of the phytoplankton. Microzooplankton herbivory, investigated using dilution experiments, was vigorous. Microzooplankton turned over between 2 and 45% of the phytoplankton standing stock daily.
AN: 3530693
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TI: Pigment signatures of the phytoplankton composition in the northeastern Atlantic during the 1990 spring bloom
AU: Barlow,-R.G.; Mantoura,-R.F.C.; Gough,-M.A.; Fileman,-T.W.
AF: Plymouth Mar. Lab., Prospect Place, West Hoe, Plymouth PL1 3DH, UK
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 459-477
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: Pigment signatures were used to track the development and composition of a phytoplankton bloom in the northeastern Atlantic during May/June 1990 using reversed-phase high-performance liquid chromatography. Chlorophyll a concentrations at 5 m increased from 1.2 to 3.7 mu g/l during the first half of May, and decreased progressively thereafter in the post-bloom stage. Multiple regression analysis of chlorophyll a and selected accessory pigments indicate that diatoms (fucoxanthin; 23-70%) and prymnesiophytes (19'-hexanoyloxyfucoxanthin; 40-20%) dominated the chlorophyll a biomass in the development phase, with prymnesiophytes dominating the post-bloom stage (45-55%). Dinoflagellates (peridinin; 5-25%) and "green" algae (chlorophyll b; 5-10%) were secondary components of the microalgal community. Depth distributions revealed that the pigment maxima occurred near the surface at 5-15 m, with concentrations decreasing rapidly below 15 m. At the peak of the bloom, diatoms (fucoxanthin) were dominant throughout the water column down to 300 m, while in the post-bloom phase, prymnesiophytes (19'-hexanoyloxyfucoxanthin) dominated the community in the upper 20 m with diatoms accumulating in deeper water. Concomitant measurements of nutrients and downwelling irradiance suggest that nitrate availability limited the growth of the phytoplankton in the upper 15 m and below this depth limitation was due to low irradiance levels.
AN: 3530692
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TI: Nitrate utilization in surface waters of the Iceland Basin during spring and summer of 1989
AU: Sambrotto,-R.N.; Martin,-J.H.; Broenkow,-W.W.; Carlson,-C.; Fitzwater,-S.E.
AF: Lamont-Doherty Geol. Obs., Columbia Univ., Palisades, NY 10964, USA
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 441-457
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: Oceanographic sampling at 59.5 degree N, 21 degree W over the spring and summer months of 1989 provided the basis to quantify the amount of new (nitrate) production and to evaluate the effect of selected environmental factors on new production. Surface water nitrate decreased linearly from 14 mu M in early April to similar to 2.5 mu M in August, and suggested that new production averaged 5.4 mmol NO sub(3)/m super(2)/day, almost double the rate suggested by a similar analysis at Ocean Weather Sta. P. Equivalent carbon export in the northern Iceland Basin would be 63 g C/m super(2) over this period. During a week in early July, it appeared that regenerated production compensated for a sharp decrease in new production to maintain carbon productivity at a fairly consistent level despite a decrease in F-ratio from 0.46 to 0.20. New production was predominantly associated with particles over 5 mu m, although a subsurface (35m) peak in super(15)NO sub(3) uptake may have been due to bacterial uptake. We suggest that light was the single-most dominant factor regulating nitrate uptake during this time. However the relationship between new production and light was non-linear in that the light efficiency of nitrate uptake varied significantly between stations in addition to variations in available light.
AN: 3530691
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TI: Size-fractionated primary productivity in the Northeast Atlantic in May-July 1989
AU: Joint,-I.; Pomroy,-A.; Savidge,-G.; Boyd,-P.
AF: NERC Plymouth Mar. Lab., Prospect Place, The Hoe, Plymouth PL1 3DH, UK
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 423-440
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: Size-fractionated primary productivity measurements were done in the northeast Atlantic from May to July 1989 as part of the Joint Global Ocean Flux Study (JGOFS) North Atlantic Bloom Experiment. Samples were taken on the 20 degree W meridian at 47, 52, 56 and 60 degree N, with most intensive sampling at 47 and 60 degree N. At the time of the first sampling at 47 degree N, the bloom was over but, at the other stations, substantial phytoplankton biomass and productivity were measured. The northward progression in maximum phytoplankton biomass was associated with increasing water stability and resulted in a decline in the concentration of nitrate and silicate in the surface mixed layer. The maxima in phytoplankton biomass and productivity were associated with phytoplankton cells that were larger than 5 mu m diameter, but the immediate pre-bloom conditions at 60 degree N were dominated by small nanoplankton (<5 mu m), which accounted for >50% of the daily productivity of 500-800 mgC/m super(2)/day. In the post-bloom conditions at 47 degree N, nanophytoplankton again became increasingly important. Picophytoplankton (<1 mu m) accounted for a constant proportion (10-15%) of the total productivity. The implications of the measured productivity of the different phytoplankton size fractions are discussed in relation to vertical flux of organic carbon and the potential transport into deep water of carbon dioxide, which has been incorporated into particulate organic matter.
AN: 3530690
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TI: Diurnal variation in surface pCO sub(2) and O sub(2) at 60 degree N, 20 degree W in the North Atlantic
AU: Robertson,-J.E.; Watson,-A.J.; Langdon,-C.; Ling,-R.D.; Wood,-J.W.
AF: Plymouth Mar. Lab., Prospect Place, West Hoe, Plymouth, PL1 3DH, UK
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 409-422
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: A method for rapid determination of the partial pressure of carbon dioxide at the sea-surface is described. The method was employed along with a pulsed oxygen electrode to monitor daily changes in surface pCO sub(2) and O sub(2) close to a drifting buoy deployed at approximately 59 degree N, 20 degree W. During a 4 day period a gradual rise in oxygen saturation and corresponding fall in pCO sub(2) was observed in the surface layer. Corrections are made for gas exchange of O sub(2) using wind speed data, the correction being an important fraction of the supersaturation observed in the water. Estimates of net community production and photosynthetic quotients are derived, giving a range of PQs from 0.9 to 1.5. Though variations in the local hydrography reduce the accuracy of these estimates, the potential of this approach to estimate productivity appears promising.
AN: 3530689
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TI: Diurnal variations of convective mixing and the spring bloom of phytoplankton
AU: Taylor,-A.H.; Stephens,-J.A.
AF: NERC Plymouth Mar. Lab., Prospect Place, West Hoe, Plymouth PL1 3DH, UK
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 389-408
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: Turbulent stirring of the surface mixed layer extends to shallower depths during the day than in the night because the increased buoyancy resulting from solar heating inhibits the mixing associated with wind action and surface heat loss. Calculations using a simple model in which a mixed layer of constant depth is more strongly coupled to deeper layers at night than during the day indicate that the reduction of mixing by day may be critical to the onset of the spring phytoplankton bloom, for this occurs at a time when there is increasing solar warming in the day and yet considerable heat loss and wind stirring at night. If the Kraus-Turner model of the mixed layer is used to estimate the mixing rates occurring during darkness, the values obtained agree with those that give realistic simulations of the spring bloom. Diurnal observations of chlorophyll a, pCO sub(2) and oxygen saturation made at 60 degree N during the Lagrangian experiment carried out in 1989 as part of the U.K. Biogeochemical Ocean Flux Study can be modelled more successfully if the day-night changes in vertical mixing are included in the same manner as the single layer model. The calculations indicate that these changes may shift the timing of the bloom by about 1 week and may account for the depth of penetration of some spring blooms. This process needs to be considered when modelling the coupling between climate and phytoplankton.
AN: 3530688
131 of 200
TI: Flow of surface waters to the west of the British Isles and in the Bay of Biscay
AU: Pingree,-R.D.
AF: Plymouth Mar. Lab., Citadel Hill, Plymouth PL1 2PB, UK
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 369-388
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: The flow of surface waters to the west of the British Isles and in the Bay of Biscay is examined from Argos buoy data representing about 10 buoy-years. The study area falls between the North Atlantic Current and the Subtropical Gyre, so mean flow conditions are particularly slack. The buoys were drogued between 30 and 550 m, and for the deeper droguing a simple method based on acceleration differences was used to determine drogue loss. From about 20 degree W, the mean easterly flow is about 2.5 cm/s. This flow divides north and south near 51 degree N with values of about 5 cm/s to the northeast. A further separation occurs either side of Rockall Bank. To the south of 51 degree N, weaker values of about 2.5 cm/s are directed southeast towards the Bay of Biscay. In the Bay of Biscay, at depths of about 400 m, a clockwise circulation was found. Mean flows over similar to 200 days were similar to <2 cm/s, the kinetic energy was similar to 60 cm super(2)/s super(2). Near the continental slopes off NW Spain surface conditions are seasonal, with a reversal of surface flow between summer and winter on the Portuguese slopes.
AN: 3530687
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TI: The physical and chemical environment and changes in community structure associated with bloom evolution: The Joint Global Flux Study North Atlantic Bloom Experiment
AU: Weeks,-A.; Conte,-M.H.; Harris,-R.P.; Bedo,-A.; Bellan,-I.; Burkill,-P.H.; Edwards,-E.S.; Harbour,-D.S.; Kennedy,-H.; et-al.
AF: Dep. Oceanogr., Univ. Southampton, Highfield, Southampton SO9 5NH, UK
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 347-368
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: The physical and chemical structure of the upper 100 m of the water column and biological parameters were measured during spring bloom development along a 20 degree W transect from 60 to 47 degree N in June 1989. At 60 degree N, the situation was that of a late bloom: weak and intermittent stratification, high nutrient concentrations, and high and variable phytoplankton biomass and production. At 47 degree N, a post-bloom situation was observed: seasonal stratification in the upper 50 m, surface nutrient depletion, a subsurface chlorophyll maximum and reduced levels of primary production. At all stations, detrital material accounted for more than two-thirds of the >0.8 mu m particulate organic carbon within the upper 100 m. Phytoplankton biomass showed no pronounced latitudinal trends, but there was a shift from >5 mu m diatoms and prymnesiophytes at 60 degree N to dinoflagellates and 1-5 mu m prymnesiophytes at 47 degree N. Nanophytoplankton comprised <5% of the biomass and <15% of the total production. Heterotrophic biomass was of the same order as phytoplankton biomass, and dominated by bacteria and microzooplankton. Microzooplankton dominated the consumption of primary production, whereas mesozooplankton accounted for <2%. Microzooplankton biomass and grazing rates doubled between 60 and 47 degree N, while mesozooplankton grazing rates more than halved. The data suggest a shift in the balance between production and consumption at different stages of the bloom.
AN: 3530686
133 of 200
TI: Pigment transformation and vertical flux in an area of convergence in the North Atlantic
AU: Head,-E.J.H.; Horne,-E.P.W.
AF: Biol. Oceanogr. Div., Bedford Inst. Oceanogr., P.O. Box 1006, Dartmouth, NS B2Y 4A2, Canada
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 329-346
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: Particulate samples from the water column, to depths of 80-120 m, were collected over a 10-day period during a bloom in the North Atlantic, near 37 degree N, 40 degree W, between 12 and 22 April 1990. These samples were analysed by HPLC for their chlorin and carotenoid content. The same analysis was carried out for samples of faecal pellets collected from copepods from depths of 0-100 m, which had fed in situ, and for material from sediment traps in the 100-500 m depth range. Water column pigment compositions were consistent with observations that diatoms and Phaeocystis were major components of the bloom. They also sometimes showed high concentrations of chlorophyllide a and a phaeophorbide a-like pigment, which may be due to algal die-off and cell autolysis. Faecal pellets contained high concentrations of pyrophaeophorbide a, lower amounts of unidentified phaeophorbides and some chlorophyll a, but none of the phaeophorbide a-like pigment found in the water column. Sediment traps contained high concentrations of the phaeophorbides characteristic of copepod faecal pellets and lower, approximately equal amounts of the water column phaeophorbide a-like pigment and chlorophyll a. The sampling area appeared to be in a jet of current, which was moving southwesterly along a front between Eastern Basin Water (to the north) and North Atlantic Central Water (to the south) and which seemed to be drawing in water from both these water masses. Areas of downwelling, thought to be associated with these convergent currents, may have accelerated the sedimentation of dead and dying phytoplankton cells.
AN: 3530685
134 of 200
TI: Biomass and production of bacteria and phytoplankton during the spring bloom in the western North Atlantic Ocean
AU: Li,-W.K.W.; Dickie,-P.M.; Harrison,-W.G.; Irwin,-B.D.
AF: Biol. Oceanogr. Div., Bedford Inst. Oceanogr., P.O. Box 1006, Dartmouth, NS B2Y 4A2, Canada
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 307-327
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: During the 1989 spring bloom in the western North Atlantic, we estimated the biomass and productivity of bacteria and phytoplankton at two sites (40 and 45 degree N) representing different water masses. At 40 degree N, almost all of the phytoplankton carbon could be accounted for by photosynthetic nanoplankton and picoplankton; in contrast, at 45 degree N, only about half was thus accounted, implying a substantial contribution by photosynthetic microplankton. At both sites, bacterial abundance was quite high (up to 2 x 10 super(9) cells/l), and the rates of bacterial production assessed by incorporation of [ super(3)H]thymidine (up to 8 pmol/l/h) and [ super(3)H]leucine (up to 240 pmol/1/h) were significant. Specific growth rates of bacteria based on [ super(3)H]thymidine incorporation were 0.08-0.25/day. Taken together, our measurements and assumptions implied a demand for primary production in the order of 16-36% over the euphotic zone or 24-78% over the upper 100 m in the water column. We conclude that ultraphytoplankton and bacteria played significant roles in the flux of carbon during the 1989 North Atlantic spring bloom.
AN: 3530684
135 of 200
TI: The western North Atlantic Bloom Experiment
AU: Harrison,-W.G.; Head,-E.J.H.; Horne,-E.P.W.; Irwin,-B.; Li,-W.K.W.; Longhurst,-A.R.; Paranjape,-M.A.; Platt,-T.
AF: Biol. Oceanogr. Div., Bedford Inst. Oceanogr., P.O. Box 1006, Dartmouth, NS B2Y 4A2, Canada
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 279-305
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: An investigation of the spring bloom was carried out in the western North Atlantic (40-50 degree W) as one component of the multi-nation Joint Global Ocean Flux Study (JGOFS) North Atlantic Bloom Experiment (NABE). The cruise track included an extended hydrographic section from 32 to 47 degree N and process studies at two week-long time-series stations at 40 and 45 degree N. Biological and chemical data collected along the transect indicated that the time-series stations were located in regions where the spring bloom was well developed; algal biomass was high and surface nutrient concentrations were reduced from maximum wintertime levels. Despite similarities in the vertical structure and magnitude of phytoplankton biomass and productivity, the two stations clearly differed in physical, chemical and other biological characteristics. Detailed depth profiles of the major autotrophic and heterotrophic microplankton groups (bacteria, phytoplankton, microzooplankton) revealed a strong vertical coherence in distribution at both sites, with maximum concentrations in the upper 50 m being typical of the spring bloom. Bacterial biomass and production were high at both stations relative to phytoplankton levels, particularly at 45 degree N, and may have contributed to the unexpectedly high residual ammonium concentrations observed below the chlorophyll maximum layer at both stations. Microzooplankton grazing dominated phytoplankton losses at both stations, with consumption as high as 88% of the daily primary production. Numerous similarities in bloom characteristics were noted between the western and eastern Atlantic study sites.
AN: 3530683
136 of 200
TI: The influence of chlorophyll pigment upon upwelling spectral radiances from the North Atlantic Ocean: An active-passive correlation spectroscopy study
AU: Hoge,-F.E.; Swift,-R.N.
AF: NASA Goddard Space Flight Cent., Wallops Flight Fac., Wallops Island, VA 23337, USA
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 265-277
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: Active-passive correlation spectroscopy (APCS) methods have been applied to airborne upwelled radiances and 532 nm pulsed laser-induced phytoplankton chlorophyll pigment fluorescence obtained during the North Atlantic Spring Bloom Experiment (NABE) of the Joint Global Ocean Flux Study (JGOFS). The active-passive spectral data obtained during a transect between Ireland and Iceland over 300 km cloud-free portion of the JGOFS 20 degree W longitude line have been subjected to two-band radiance-ratio analyses. The chlorophyll pigment was found to significantly influence the upwelled radiances over considerable portions of the observed 380-740 nm color spectrum. Satisfactory recovery of chlorophyll pigment concentrated in North Atlantic case 1 waters was obtained over a broad region of the blue-green spectrum ( similar to 430-530 nm) when ratioed with bands of the green-yellow spectrum ( similar to 540-585 nm). The data confirm that the 420/550 nm band combination out-performs 443/550 nm for chlorophyll concentrations greater than or approximate to 1.5 mg m super(-3); however, the results indicate that further improvement could be realized using the 490 nm band in combination with either the 555 or 565 nm bands. Chlorophyll pigment was found to be recoverable using the 652/685 nm chlorophyll absorption/fluorescence radiance ratio. Other findings include satisfactory chlorophyll recovery using the 415 nm band ratioed with bands in the 562-584 nm spectral region, suggesting that these waters were bloom dominated with a relatively low concentration of dissolved organic matter (DOM). This latter finding agrees with low DOM fluorescence values found using an auxiliary 355 nm laser excitation source. To illustrate these experimental findings, radiance-ratio spectral correlation matrices are presented together with corresponding along-track active/passive cross-sectional profiles.
AN: 3530682
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TI: Stocks and dynamics of bacterioplankton carbon during the spring bloom in the eastern North Atlantic Ocean
AU: Ducklow,-H.W.; Kirchman,-D.L.; Quinby,-H.L.; Carlson,-C.A.; Dam,-H.G.
AF: Horn Point Environ. Lab., P.O. Box 775, Cambridge, MD 21613-0775, USA
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 245-263
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: Bacterial biomass increased five-fold in the euphotic zone (from 450 to 2250 mgC/m super(2)) in response to the spring phytoplankton bloom in the eastern North Atlantic Ocean (Lat. 47 degree N, Long, 20 degree W) in 1989. Bacterial biomass accounted for about 20-30% of the particulate organic carbon (POC) above 50 m and a somewhat larger fraction in the layer below. Bacterial production averaged about 30% of primary production and remained rather constant while the primary production varied from 600 to 1500 mgC/m super(2)/day in response to event-scale changes in gradiance. Thus bacterial production varied from 15 to 80% of the concurrent primary production, with peaks occurring on overcast days when photosynthesis was low. Bacterial production in both the euphotic zone and the layer immediately below appeared to respond to the meteorologically-driven variations in photosynthesis with a time lag of 3-4 days, consistent with estimates of turnover rates of 0.2/day. Our observations suggest a spring-time North Atlantic condition for the microbial foodweb in which bacterial biomass makes up a relatively small part of the plankton carbon stock, but cycles rapidly (0.1-0.3/day) and commands a large share of the carbon cycling in the upper ocean.
AN: 3530681
138 of 200
TI: Plankton community response to sequential silicate and nitrate depletion during the 1989 North Atlantic spring bloom
AU: Sieracki,-M.E.; Verity,-P.G.; Stoecker,-D.K.
AF: Bigelow Lab. Ocean Sci., McKown Pt., W. Boothbay Harbor, ME 04575, USA
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 213-225
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: The onset of the North Atlantic spring bloom is controlled by physical conditions and nutrient availability in the surface layer. The nutrient of interest is usually considered to be nitrate. In an intensive study of the 1989 bloom near 46 degree N, 18 degree W, dissolved silicate was rapidly depleted to a minimum before nitrate was depleted. This coincided with a shift in dominant phytoplankton from diatoms to small flagellates. The cyanobacteria, nanoplankton and some components of the microplankton community were followed over the course of two cruises through April and May. A true-color image analysis system, combined with epifluorescence microscopy, was used to yield rapid semi-automated measurements of cell abundances, population size spectra and trophic classification. Although few direct measurements of diatom abundance or biomass were made, the diatom bloom appeared rapidly and sank (or was grazed) over the course of 2-3 weeks. The diatoms were replaced by a community of abundant, small phytoflagellates, presumed to be primarily prymnesiophytes, and chlorophyll levels remained high. Similarly abundant and small aplastidic (heterotrophic) flagellates coincided with the plastidic flagellates. Carbon standing stock budgets, as well as direct microscopic observations, indicated a large amount of detritus in the water column near the end of the diatom bloom that was not present 2 weeks later. The zooplankton community was dominated by protozoans and copepod nauplii, and mixotrophic ciliates increased significantly over the study period. The nutrient-controlled shift in phytoplankton community composition apparently reduced the flux of recently fixed carbon out of the surface and increased recycling and mixotrophy in the surface layer.
AN: 3530680
139 of 200
TI: Biophysical forcing of particle production and distribution during a spring bloom in the North Atlantic
AU: Gardner,-W.D.; Walsh,-I.D.; Richardson,-M.J.
AF: Dep. Oceanogr., Texas A&M Univ., College Stn., TX 77843-4146, USA
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 171-195
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: As part of the North Atlantic Bloom Experiment (NABE), CTD/transmissometer profiles were made on two cruises at 47 degree N, 20 degree W in spring 1989 to quantify the increase in particles during a phytoplankton bloom in relationship to biophysical forcing factors. Water samples were filtered to obtain particle mass concentrations for calibration of beam attenuation (beam c) from the transmissometer. Shipboard experiments demonstrated that beam c resulted primarily from the concentration of small particles (<20 mu m), with little signal coming from the aggregates or dregs that settle to the bottom of water bottles. Profiles of beam attenuation showed a three-fold increase in the surface mixed layer over a 2-week period. Superimposed on this increase were daily variations with evening highs and morning lows. Increases in beam attenuation resulted primarily from increases in particle mass generated through primary production. Wind mixing, stratification and solar radiation were obvious influences on the rate of particle increase in surface waters. Depth-integration of beam attenuation over 20 and 50 m revealed that the increase in derived particle organic carbon (POC) can account for only about 18-28% of the drawdown of total CO sub(2). Fluxes measured by drifting sediment traps at 150 m can be satisfied by the settling of only 2-4%/day of the standing crop in the upper 100 m, but the particles would have to be converted into larger, more rapidly settling particles to be collected effectively in sediment traps. Based on the drawdown of CO sub(2) and the standing crop of particles, significant primary production must have occurred before we arrived on day 115. Our data demonstrate that the transmissometer is an effective optical tool in monitoring the dynamics of particles in surface waters and its signal can be quantitatively related to biological processes in the ocean.
AN: 3530679
140 of 200
TI: Primary production at 47 degree N and 20 degree W in the North Atlantic Ocean: A comparison between the super(14)C incubation method and the mixed layer carbon budget
AU: Chipman,-D.W.; Marra,-J.; Takahashi,-T.
AF: Lamont-Doherty Geol. Obs., Columbia Univ., Palisades, NY 10964, USA
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 151-169
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: Primary production in the oceans has been estimated mainly on the basis of in vitro incubation measurements. An implicit assumption is that the growth rate of phytoplankton observed in vitro represents that occurring in the freely circulating water of the euphotic zone. We have tested this assumption at 47 degree N-20 degree W in the eastern North Atlantic Ocean during the initial stages of a spring phytoplankton bloom. The daily primary production was measured by means of the super(14)C assimilation method, in which the incubation bottles were suspended in the ocean from down to dusk daily (about 14 h). The mean daily carbon assimilation rate in the photic zone and in the mixed layer was 107 plus or minus 23 and 84 plus or minus 18 mmol C/m super(2)/day (where day* = 14 daylight hours), respectively, during the 12-day period between 26 April and 7 May 1989. The mixed layer carbon assimilation data are found to be consistent with the in situ CO sub(2) utilization rate of 82 plus or minus 17 mmol C/m super(2)/day* estimated on the basis of the thickness of surface mixed layer, the CO sub(2) concentration in it, and the air-sea CO sub(2) flux. We conclude that primary production in the open ocean appears to be well represented by the in vitro measurements, if the samples are incubated under the in situ light and temperature conditions. The mean daily reduction rate of the total CO sub(2) concentration observed in the mixed layer over the 12-day period is 2.3 mu mol/kg/day, about 75% of the rate, 3.1 mu mol/kg/day*, expected from the rate of primary production. About 8.5% of this difference is explained by the atmospheric CO sub(2) flux, and the remaining 16.5% may be attributed to the respiration and the influx of CO sub(2)-rich waters from the mixed layer.
AN: 3530678
141 of 200
TI: Benthic response to the sedimentation of particulate organic matter at the BIOTRANS station, 47 degree N, 20 degree W
AU: Pfannkuche,-O.
AF: Abt. Mar. Mikrobiol., Inst. Meereskd., Duesternbrooker Weg 20, D-2300 Kiel 1, FRG
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 135-149
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: The benthic response to the sedimentation of particulate organic matter (POM) was investigated during 1985-1990 at 47 degree N, 20 degree W (BIOTRANS station). The first noticeable annual sedimentation of phytodetritus, as indicated by chlorophyll a concentrations in the sediment, occurred as early as late April-early May. Maximum amounts were found in June-July. Two different sedimentation pulses to the sea bed are described that demonstrate interannual variation: the occurrence of salp faecal pellets early in the year 1988 and the massive fall out of a plankton bloom in summer 1986, which deposited approximately 15 mmol C/m super(2). The benthic reaction to POM pulses was quite diverse. The mega-, macro- and meiobenthos showed no change in biomass, whereas bacterial biomass doubled between March and July. This corresponds to a seasonal maximum of total adenylate biomass. The relative abundance of Foraminifera among the meiobenthos increased during the summer. Benthic activity (ATP, ratio ATP/ETSA), as well as in situ sediment community oxygen consumption rates (SCOC), showed distinct seasonal maxima in July-August of 0.75 mmol C/m super(2)/day. Based on SCOC and the carbon demand for growth, a benthic carbon consumption of 0.94 mmol C/m super(2)/day was estimated. This represents about 1.1% of spring bloom primary production and 9.6% of the export flux beneath the 150 m layer, measured during the North Atlantic Bloom Experiment. Bacteria and protozoans colonizing the epibenthic phytodetrital layer were responsible for 60-80% of the seasonal increase in SCOC. The strong reaction of the smaller benthic size groups (bacteria, protozoans) to POM pulses stresses their particular importance for sediment-water interface flux rates.
AN: 3530677
142 of 200
TI: Iron, primary production and carbon-nitrogen flux studies during the JGOFS North Atlantic Bloom Experiment
AU: Martin,-J.H.; Fitzwater,-S.E.; Gordon,-R.M.; Hunter,-C.N.; Tanner,-S.J.
AF: Moss Landing Mar. Lab., Moss Landing, CA 95039, USA
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 115-134
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: Primary production was measured every other day towards the end (18-31 May) of the 1989 North Atlantic spring bloom. Rates varied with light and averaged 90.4 mmol C/m super(2)/day at the 47 degree N, 20 degree W station. Productivities measured south of Iceland (59 degree 30'N, 20 degree 45'W) were somewhat lower, averaging 83.6 mmol C/m super(2)/day. Carbon and nitrogen fluxes were estimated using free-floating, VERTEX type particle trap arrays. To obtain mean rates representative of the North Atlantic spring bloom, flux data from three trap deployments were combined and fitted to normalized power functions. Concentrations of Cu, Fe, Ni, Pb and Zn were determined in water samples provided by JGOFS NABE scientists involved with primary productivity measurements. Although little contamination was observed for Cu, Ni and Pb, relatively large amounts of Zn (10 nmol/kg) were found in some cases. In subsequent studies it was learned that this quantity of Zn can depress productivity rates by 25%. North Atlantic dissolved Fe concentrations were similar to those occurring in the Pacific (surface = 0.07; deep = 0.5-0.6 nmol/kg). Although no evidence of Fe deficiency was found in enrichment experiments, the addition of nmol amounts of Fe did increase CO sub(2) uptake and POC formation by factors of 1.3-1.7. In this region, most of the phytoplankton's Fe requirement is probably met via the lateral transport of Fe from distant continental margins.
AN: 3530676
143 of 200
TI: Plankton succession and carbon cycling at 47 degree N 20 degree W during the JGOFS North Atlantic Bloom Experiment
AU: Lochte,-K.; Ducklow,-H.W.; Fasham,-M.J.R.; Stienen,-C.
AF: Inst. Pol. Mar. Sci., P.O. Box 120161, D-2850 Bremerhaven, FRG
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 91-114
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: An overview is given of the multinational investigations carried out at 47 degree N 20 degree W, with the main emphasis on the succession of plankton communities and of the link of organic carbon through various plankton components.
AN: 3530675
144 of 200
TI: The "f-ratio" on 20 degree W during the North Atlantic Bloom Experiment
AU: Garside,-C.; Garside,-J.C.
AF: Bigelow Lab. Ocean Sci., McKown Pt., W. Boothbay Harbor, ME 04575, USA
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 75-90
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: We have used data gathered during the North Atlantic Bloom Experiment to model new and total production, and the f-ratio on 20 degree W. The results imply that as much as half the spring bloom total production occurs well in advance of stratification. However, although new production potentially equals export production into the interior of the ocean, observations during NABE, and the model suggest that this export may not be fully realized during the bloom, and may be trapped and recycled in the upper water column during the year.
AN: 3530674
145 of 200
TI: Initiation of the spring bloom in the Northeast Atlantic (47 degree N, 20 degree W): A numerical simulation
AU: Marra,-J.; Ho,-Cheng
AF: Lamont-Doherty Geol. Obs., Columbia Univ., Palisades, NY 10964, USA
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 55-73
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: We have applied a mixed layer model and a simple biological model to examine spring phytoplankton increase observed during the North Atlantic Bloom Experiment of the Joint Global Ocean Flux Study. Despite spatial variability in water column conditions, the one-dimensional mixed-layer model reproduced satisfactorily the increasing stratification during the 2-week observation period. Likewise, the gradient and extent of nutrient removal (exemplified by nitrate) and the timing of the increase in phytoplankton biomass (represented by chlorophyll a) compared reasonably well between the model and observations. The cell-quota formulation for phytoplankton growth, and an adaptive feeding model for zooplankton appear to be necessary to accord with the observations. On the other hand, adaptive feeding by zooplankton makes the model sensitive to the choice of a maximum growth rate in phytoplankton. Zooplankton were probably not a factor early in the simulation, but according to the model, exerted significant grazing pressure by the end of the observational period.
AN: 3530673
146 of 200
TI: Spatial variability in near-surface chlorophyll a fluorescence measured by the Airborne Oceanographic Lidar (AOL)
AU: Yoder,-J.A.; Aiken,-J.; Swift,-R.N.; Hoge,-F.E.; Stegmann,-P.M.
AF: Grad. Sch. Oceanogr., Univ. Rhode Island, S. Ferry Rd, Narragansett, RI 02882, USA
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 37-53
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: The primary purpose of the aircraft remote sensing component of the North Atlantic Bloom Experiment (NABE) was to: (1) quantify spatial patterns of surface Chl a variability and co-variability with temperature (T) within the NABE study regions along the 20 degree W meridian near 48 and 60 degree N; and (2) determine if the major NABE ship and mooring locations were representative of surrounding ocean waters with respect to large-scale distributions of surface Chl a and T. The sampling platform was a NASA P-3 aircraft equipped with the Airborne Oceanographic Lidar (AOL) system, which measures laser-induced Chl a fluorescence (LICF), upwelling spectral radiance and surface temperature (T). Results collected during nine AOL missions conducted between 26 April and 3 June show considerable mesoscale variability in LICF and T. Our analyses show that satellite ocean color scanners with pixel resolution of 4 x 4 km will generally detect the major spatial patterns of Chl a distributions (at scales >0.3 km) in near surface waters during the spring bloom in the North Atlantic.
AN: 3530672
147 of 200
TI: Mesoscale and upper ocean variabilities during the 1989 JGOFS bloom study
AU: Robinson,-A.R.; McGillicuddy,-D.J.; Calman,-J.; Ducklow,-H.W.; Fasham,-M.J.R.; Hoge,-F.E.; Leslie,-W.G.; McCarthy,-J.J.; Podewski,-S.; et-al.
AF: Dep. Earth Planet. Sci., Harvard Univ., Cambridge, MA 02138, USA
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 9-35
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: Altimetric data from Geosat and some critical hydrographic measurements were used to estimate in real time the mesoscale physical oceanographic environment surrounding the Joint Global Ocean Flux Study (JGOFS) 1989 North Atlantic Bloom Experiment. Three cyclonic eddies, including an exceptionally large one, evolved and interacted over the 10 weeks of observations. Subsequent analysis of all available hydrographic data confirmed the real time estimates and provided further quantitative information concerning the mesoscale and submesoscale structure of the upper ocean. Remotely sensed indicators of near-surface chlorophyll content reveal significant biological variability on these wavelengths. The altimetric and hydrographic data have been assimilated into a dynamical model to produce optimal estimates of physical fields of interest as they evolve in time for use in physical and biological process studies.
AN: 3530671
148 of 200
TI: Introduction to the JGOFS North Atlantic Bloom Experiment
AU: Ducklow,-H.W.; Harris,-R.P.
AF: Horn Point Environ. Lab., Univ. Maryland CEES, P.O. Box 775, Cambridge, MD 21613 0775, USA
SO: JGOFS:-THE-NORTH-ATLANTIC-BLOOM-EXPERIMENT. Ducklow,-H.W.;Harris,-R.P.-eds. 1993 vol. 40, no. 1-2 pp. 1-8
ST: DEEP-SEA-RES.-2-TOP.-STUD.-OCEANOGR. vol. 40, no. 1-2
LA: English
ER: M (Marine)
AB: This issue contains the first collection of papers from the Joint Global Ocean Flux Study (JGOFS). Formed as an international program in 1987, JGOFS has four principal elements: modelling and data management, multidisciplinary regional process studies, a global survey of biogeochemical properties and long-term time series observations. In 1989-1990 JGOFS conducted a pilot process study of the spring phytoplankton bloom, the North Atlantic Bloom Experiment (NABE). JGOFS decided to conduct a large-scale, internationally-coordinated pilot study in the North Atlantic because of its proximity to the founding nations of the project, the size and predictability of the bloom, and its fundamental impact on ocean biogeochemistry. In 1989, six research vessels from Canada, Germany, The Netherlands, the U.K. and the U.S.A., and over 200 scientists and students from more than a dozen nations participated in NABE. Some of their initial results are reported in this volume. The spring bloom in the North Atlantic is one of the most conspicuous seasonal events in the world ocean. Coastal Zone Color Scanner (CZCS) imagery shows that the bloom is manifested as a sudden explosion of ocean color that fills the basin north of about 40 degrees latitude in April and May each year.
AN: 3530670
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TI: Grazing, growth and mortality of microzooplankton during the 1989 North Atlantic spring bloom at 47 degree N, 18 degree W
AU: Verity,-P.G.; Stoecker,-D.K.; Sieracki,-M.E.; Nelson,-J.R.
AF: Skidaway Inst. Oceanogr., P.O. Box 13687, Savannah, GA 31416, USA
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1993 vol. 40, no. 9, pp. 1793-1814
LA: English
ER: M (Marine)
AB: Grazing and growth rates of nano- and microzooplankton were measured as part of the 1989 North Atlantic Bloom Experiment, an interdisciplinary research program of the Joint Global Ocean Flux Study (JGOFS). Samples for shipboard experimental incubations were collected from the mixed layer of a drogued water mass (46 degree 20'N, 17 degree 50'W) over a 2 week period in May. Grazing and growth rates, measured using the size fractionation and dilution techniques, were calculated from changes in chlorophylls, accessory pigments, and cell abundances. The phytoplankton community was dominated by phytoflagellates, primarily prymnesiophytes, which passed 10 mu m mesh. Chlorophyll a (Chl a) increased at an average rate of 0.9 doublings/day when incubated at 60 % I sub(o). Grazing by nano- and microzooplankton removed 37-100% of estimated primary production in samples from 10 m, and 100% of that at 30 m. An attempt was made to budget estimated rates of community grazing to major groups of nano- and microzooplankton, using measured biomass and specific ingestion or growth rates from laboratory studies. Aplastidic microflagellates were apparently the most important herbivores. In addition to ciliates and heterotrophic dinoflagellates, various developmental stages of copepods were abundant in the <200 mu m fraction. Predation within the microzooplankton community appeared to be substantial. Given the evidence of tight coupling between production and consumption within the upper water column, little material appeared to be available for direct export from the mixed layer to depth during this phase of the spring bloom.
AN: 3529189
150 of 200
TI: Application of a generalized scavenging model to time series super(234)Th and particle data obtained during the JGOFS North Atlantic Bloom Experiment
AU: Clegg,-S.L.; Whitfield,-M.
AF: Sch. Environ. Sci., Univ. East Anglia, Norwich NR4 7TJ, UK
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1993 vol. 40, no. 8, pp. 1529-1545
LA: English
ER: M (Marine)
AB: Primary production, particle concentration and flux data, obtained as part of the JGOFS North Atlantic Bloom Experiment, have been used to construct a self consistent, time dependent, particle cycle model for the upper water column for the period 25 April-30 May 1989. Daily super(234)Th concentrations and fluxes are modelled over the course of the bloom, and the results compared with available data. Use of a single pseudo-first-order rate constant k sub(1)' for the adsorption of super(234)Th onto particulate material in the model gives satisfactory agreement with measured super(234)Th profiles. Modelled concentrations of super(234)Th on large, sinking particles--which must be known in order to calculate particle fluxes from super(234)Th disequilibrium-are predicted well by the model. The results also suggest that particle fluxes determined from sediment traps may be systematically low.
AN: 3519918
151 of 200
TI: Mare cognitum. Science plan for research on marine ecology of the Nordic Seas (Greenland, Norwegian, Iceland Seas) 1993-2000. A regional GLOBEC program with contributions also to WOCE and JGOFS
AU: Skjoldal,-H.R.; Noji,-T.T.; Giske,-J.; Fossaa,-J.H.; Blindheim,-J.; Sundby,-S.
AF: Inst. Mar. Res., P.O. Box 1870 Nordnes, N-5024 Bergen, Norway
SO: BERGEN-NORWAY INST.-MAR.-RES. 1993 162 pp
LA: English
ER: M (Marine)
AB: Findings from long-term time series on climate and fish stocks indicate that there exists 1) a strong element of periodicity in the various of ocean climate, and 2) a strong coupling between climatic variation and variations in recruitment and size of important commercial fish stocks. These findings are the basis for the overall goals set for Mare Cognitum.
AN: 3519707
152 of 200
TI: EUMELI oligotrophic site: Response of an upper ocean model to climatological and ECMWF atmospheric forcing
AU: Dadou,-I.C.; Garcon,-V.C.
AF: UMR39, CNRS/GRGS, 18 Ave. Edouard Belin, 31055 Toulouse Cedex, France
SO: J.-MAR.-SYST. 1993 vol. 4, no. 5, pp. 371-390
LA: English
ER: M (Marine)
AB: Within the frame of the EUMELI program--component of FRANCE-JGOFS--in the Northeast Tropical Atlantic ocean, we investigate the potential of a one-dimensional eddy-kinetic-energy model (Gaspar et al., 1990, GGL) to characterize the vertical dynamics of the oceanic mixed layer (ML) at the EUMELI oligotrophic site (21 degree N, 31 degree W) north of the Cape Verde Frontal Zone. The atmospheric forcings used are derived from two different sources: the operational Atmospheric General Circulation Model of ECMWF (over two 12-month periods: August 1985-July 1986 and the full year 1990) and climatologies (Esbensen and Kushnir, EK, 1981; Hsiung, H. 1986; Oort, 1983). Sampling experiments on the surface boundary conditions showed that simulated evolutions of the ML depth and SST differ quite significantly due to differences in data bases rather than differences in forcing frequencies. An error analysis on the ocean surface energy fluxes and the prescription of evaporation and precipitation rates under various forms demonstrate the crucial need for heat, momentum and freshwater fluxes estimates as accurate as possible. From the distributions of the turbulent kinetic energy (TKE) budget on different time scales, it is found that most often shear production and viscous dissipation dominate in the ML. Gravitational production or destruction, turbulent diffusion and storage of TKE are of second-order. The use of a daily instead of a 3-hour forcing creates an underestimation of 19% of the total annual energy produced by the shear. When taking into account freshwater fluxes, gravitational production becomes of first order during fall and winter and intervenes in the balance between shear production and viscous dissipation.
AN: 3516881
153 of 200
TI: Thorium isotopes as indicators of particle dynamics in the upper ocean: Results from the JGOFS North Atlantic Bloom Experiment
AU: Cochran,-J.K.; Buesseler,-K.O.; Bacon,-M.P.; Livingston,-H.D.
AF: Mar. Sci. Res. Cent., SUNY, Stony Brook, NY 11794-5000, USA
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1993 vol. 40, no. 8, pp. 1569-1595
LA: English
ER: M (Marine)
AB: Measurements of super(234)Th and super(228)Th in suspended and sinking particles made during the 1989 JGOFS North Atlantic Bloom Experiment permit estimation of the rates of particle cycling. Using a simple model of thorium-particle interactions applied to water column and floating sediment trap data at 150 and 300 m, the rate constant, beta sub(2), for aggregation of small suspended particles into large rapidly sinking ( similar to 150 m/day) particles increases from similar to 0 to similar to 30/y over the course of the bloom. The rate constant for disaggregation of sinking particles, beta sub(-2), similarly increases from similar to 100 to similar to 300/y over the same period. These values suggest that small particle residence times (relative to packaging or aggregation) decrease to similar to 15 days and that large particle residence times (relative to disaggregation) decrease to similar to 1 day as the bloom progresses. Late in the bloom, particles are cycled such that aggregation of suspended particles ( similar to 2 mu g/l/day) is comparable to particle break up ( similar to 3 mu g/l/day).
AN: 3509966
154 of 200
TI: Alkenone and alkenoate distributions within the euphotic zone of the eastern North Atlantic: Correlation with production temperature
AU: Conte,-M.H.; Eglinton,-G.
AF: Univ. Bristol, Sch. Chem., Org. Geochem. Unit, Bristol BS8 1TS, UK
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP. 1993 vol. 40, no. 10, pp. 1935-1961
LA: English
ER: M (Marine)
AB: This paper reports the concentrations and within-class distributions of long-chain alkenones and alkyl alkenoates in the surface waters (0-50 m) of the eastern North Atlantic, and correlates their abundance and distribution with those of source organisms and with water temperature and other environemntal variables. We collected these samples of > 0.8 mu m particulate material from the euphotic zone along the JGOFS 20 degree W longitude transect, from 61 degree N to 24 degree N, during seven cruises of the UK-JGOFS Biogeochemical Ocean Flux Study (BOFS) in 1989-1991; the biogeographical range of our 53 samples extends from the cold (< 10 degree C), nutrient-rich and highly productive subarctic waters of the Iceland Basin to the warm (> 25 degree C) oligotrophic subtropical waters off Africa. Surface water concentrations of total alkenone and alkenoates ranged from < 50 ng/l in oligotrophic waters below 40 degree N to 2000-4500 ng/l in high latitude E. huxleyi blooms, and were well correlated with E. huxleyi cell densities, supporting the assumption that E. huxleyi is the predominant source of these compounds in the present day North Atlantic.
AN: 3509488
155 of 200
TI: Ocean time-series near Bermuda: Hydrostation S and the U.S. JGOFS Bermuda Atlantic time-series study
AU: Michaels,-A.F.; Knap,-A.H.
AF: Bermuda Biol. Stn., Ferry Reach, St. Georges, Bermuda
CO: Ocean Climate Data Workshop, Greenbelt, MD (USA), 18-21 Feb 1992
SO: PROCEEDINGS-OF-THE-OCEAN-CLIMATE-DATA-WORKSHOP. Churgin,-J.-comp. GREENBELT,-MD-USA NASA-GODDARD-SPACE-FLIGHT-CENT. 1993 pp. 295-316
LA: English
ER: M (Marine)
AB: Bermuda is the site of two ocean time-series programs. At Hydrostation S, the ongoing biweekly profiles of temperature, salinity and oxygen now span 37 years. This is one of the longest open-ocean time-series datasets and provides a view of decadal scale variability in ocean processes. In 1988, the U.S. JGOFS Bermuda Atlantic Time-series Study began a wide range of measurements at a frequency of 14-18 cruises each year to understand temporal variability in ocean biogeochemistry. On each cruise, the data range from chemical analyses of discrete water samples to data from electronic packages of hydrographic and optics sensors. In addition, a range of biological and geochemical rate measurements are conducted that integrate over time-periods of minutes to days. This sampling strategy yields a reasonable resolution of the major seasonal patterns and of decadal scale variability. The Sargasso Sea also has a variety of episodic production events on scales of days to weeks and these are only poorly resolved. In addition, there is a substantial amount of mesoscale variability in this region and some of the perceived temporal patterns are caused by the intersection of the biweekly sampling with the natural spatial variability. In the Bermuda time-series programs, the authors have added a series of additional cruises to begin to assess these other sources of variation and their impacts on the interpretation of the main time-series record. However, the adequate resolution of higher frequency temporal patterns will probably require the introduction of new sampling strategies and some emerging technologies such as biogeochemical moorings and autonomous underwater vehicles.
AN: 3506608
156 of 200
TI: Management and assimilation of satellite data for JGOFS
AU: Evans,-R.
AF: Rosentiel Sch. Mar. Atmos. Sci., Univ. Miami, 4600 Rickenbacker Causeway, Miami, FL 33149-1098, USA
CO: Ocean Climate Data Workshop, Greenbelt, MD (USA), 18-21 Feb 1992
SO: PROCEEDINGS-OF-THE-OCEAN-CLIMATE-DATA-WORKSHOP. Churgin,-J.-comp. GREENBELT,-MD-USA NASA-GODDARD-SPACE-FLIGHT-CENT. 1993 p. 275
NT: Summary only.
LA: English
ER: M (Marine)
AB: The author describes the data flow that has been established for JGOFS and notes that understanding this flow was essential to understanding the data base. The complete suite of sensors as well as data transfers all need to be considered. This includes the process from initial satellite recordings to the final geophysical values that these represent. Further he illustrated the coordination that needs to be established between the satellite and field programs. Using SEAWIFS as an example, the usages and product delivery needs all must be considered. Presumed geophysical values must also undergo a quality assessment that involves in situ air and sea values. Finally you wind up with suites of data and data products that are available in time scales from near-real time to months or even years later. It was noted that changes in algorithms, correction factors and calibration require that data be available for reanalysis at later dates. Using AVHRR as an example, it is shown the level of effort that was required in order to build this high quality time series data set, complete with error bars. This is the type of data that is most useful to climate studies but it required working and reworking buoy data used as sea truth and AVHRR data from satellites. Some critical elements required for a successful system are: Timely access, simple mechanisms which allow one to include all partners in a large project, allowance for metadata so users are aware of how product was derived and distributed system interfaces that readily accessible and easy to use.
AN: 3506594
157 of 200
TI: Data management for community research projects: A JGOFS case study
AU: Lowry,-R.K.
AF: Proudman Oceanogr. Lab., Bidston Obs., Bidston, Birkenhead, Merseyside L43 7RA, UK
CO: Ocean Climate Data Workshop, Greenbelt, MD (USA), 18-21 Feb 1992
SO: PROCEEDINGS-OF-THE-OCEAN-CLIMATE-DATA-WORKSHOP. Churgin,-J.-comp. GREENBELT,-MD-USA NASA-GODDARD-SPACE-FLIGHT-CENT. 1993 pp. 251-273
LA: English
ER: M (Marine)
AB: Since the mid 1980s, much of the marine science research effort in the United Kingdom has been focused into large scale collaborative projects involving public sector laboratories and university departments, termed Community Research Projects. Two of these, the Biogeochemical Ocean Flux Study (BOFS), and the North Sea Project incorporated large scale data collection to underpin multidisciplinary modeling efforts. The challenge of providing project data sets to support the science was met by a small team within the British Oceanographic Data Centre (BODC) operating as a topical data centre. The role of the data centre was to both work up the data from the ship's sensors and to combine these data with sample measurements into on-line databases. The working up of the data was achived by a unique symbiosis between data centre staff and project scientists. The project management, programming and data processing skills of the data centre were combined with the oceanographic experience of the project communities to develop a system which has produced quality controlled, calibrated data sets from 49 research cruises in 3.5 years of operation. The data centre resources required to achieve this were modest and far outweighed by the time liberated in the scientific community by the removal of the data processing burden. However, projects covering a larger, even international scale could be successfully supported by a network of topical data centres managing online databases which are interconnected by object oriented distributed data management systems over wide area networks.
AN: 3506585
158 of 200
TI: Data management for JGOFS: Theory and design
AU: Flierl,-G.R.; Bishop,-J.K.B.; Glover,-D.M.; Paranjpe,-S.
CO: Ocean Climate Data Workshop, Greenbelt, MD (USA), 18-21 Feb 1992
SO: PROCEEDINGS-OF-THE-OCEAN-CLIMATE-DATA-WORKSHOP. Churgin,-J.-comp. GREENBELT,-MD-USA NASA-GODDARD-SPACE-FLIGHT-CENT. 1993 pp. 229-249
LA: English
ER: M (Marine)
AB: The Joint Global Ocean Flux Study (JGOFS), currently being organized under the auspices of the Scientific Committee for Ocean Research (SCOR), is intended to be a decade long internationally coordinated program. The main goal of JGOFS is to determine and understand on a global scale the processes controlling the time-varying fluxes of carbon and associated biogenic elements in the ocean and to evaluate the related exchanges with the atmosphere, sea floor and continental boundaries. A long-term goal of JGOFS will be to establish strategies for observating, on long time scales, changes in ocean biogeochemical cycles in relation to climate change. Participation from a large number of U.S. and foreign institutions is expected. JGOFS investigators have begun a set of time-series measurements and global surveys of a wide variety of biological, chemical and physical quantities, detailed process-oriented studies, satellite observations of ocean color and wind stress and modeling of the bio-geochemical processes. These experiments will generate data in amounts unprecedented in the biological and chemical communities; rapid and effortless of these data will be important to the success of JGOFS. The authors discuss the possibility for the user of a small computer connected to a network to be able to locate and work with data at NODC or indeed anywhere in a distributed data base without regards to its location or format.
AN: 3506576
159 of 200
TI: The JGOFS North Atlantic Bloom Experiment: An overview
AU: Ducklow,-H.W.
AF: Horn Point Mar. Lab., Univ. Maryland, Cambridge, MD 21613, USA
CO: Ocean Climate Data Workshop, Greenbelt, MD (USA), 18-21 Feb 1992
SO: PROCEEDINGS-OF-THE-OCEAN-CLIMATE-DATA-WORKSHOP. Churgin,-J.-comp. GREENBELT,-MD-USA NASA-GODDARD-SPACE-FLIGHT-CENT. 1993 pp. 205-227
LA: English
ER: M (Marine)
AB: The North Atlantic Bloom Experiment (NABE) of the Joint Global Ocean Flux Study (JGOFS) presents a unique opportunity and challenge to the data management community because of the diversity and large size of biogeochemical data sets collected. NABE was a pilot study for JGOFS and has also served as a pilot study within the US NODC for management and archiving of the data sets. The author presents an overview to some of the scientific results of NABE, which will be published as an Introduction to a special volume of NABE results in Deep-Sea Research. An overview of NABE data management is given elsewhere in the present report. This is the first collection of papers from JGOFS. Formed as an international program in 1987, JGOFS has four principal elements: modelling and data management, multidisciplinary regional process studies, a global survey of biogeochemical properties and long-term time series observatories. In 1989-90 JGOFS conducted a pilot process study of the spring phytoplankton bloom, the North Atlantic Bloom Experiment (NABE). JGOFS decided to conduct a large scale, internationally-coordinated pilot study in the North Atlantic because of its proximity to the founding nations of the project, the size and predictability of the bloom and its fundamental impact on ocean biogeochemistry.
AN: 3506564
160 of 200
TI: Effect of change in the ocean and on the life cycle
AU: Ducklow,-H.-(conv.)
AF: Horn Point Mar. Lab., Univ. Maryland, Cambridge, MD 21613, USA
CO: Ocean Climate Data Workshop, Greenbelt, MD (USA), 18-21 Feb 1992
SO: PROCEEDINGS-OF-THE-OCEAN-CLIMATE-DATA-WORKSHOP. Churgin,-J.-comp. GREENBELT,-MD-USA NASA-GODDARD-SPACE-FLIGHT-CENT. 1993 p. 203
NT: Summary only.
LA: English
ER: M (Marine)
AB: In order to have a more complete discussion of the chemical and biological data management needs in relation to the oceans and climate change this session directed its attention on the Joint Global Ocean Flux Study (JGOFS) and particularly on the 1989 North Atlantic Bloom Experiment (NABE). The talk given by Evans added a more general discussion of data management for satellite derived parameters. Similarly the paper presented by Gamble added a more general discussion on the availability and use of time series biological data. Both of the papers on data management (Flierl & Lowry) resulted in a number of questions and comments both during this session and in formulating recommendations and issues for future discussion. It was noted by many that schemes such as the JGOFS/BOFS Topical Centres in the United Kingdom (and others in WOCE & TOGA) were the best way to ensure rapid delivery and high quality data to project scientists and eventually to the World Data Center system. Introduction of the JGOFS program enabled the participants to focus on a truly multi-disciplinary project. Not only is the program multi-disciplinary, but most of the presentations were on what happened (or is happening) when plans are put into practice. Thus Workshop attendees were able to make recommendations that directly meet the objectives of the Workshop and may also serve as a guideline to other global change research in the future.
AN: 3506556
161 of 200
TI: Role of the ocean in climate changes (ROCC)
AU: Gulev,-S.K.
AF: State Oceanogr. Inst., Hydrometeorol. Comm. Russia, Kropotkinsky per., 6 Moscow 119838, Russia
CO: Ocean Climate Data Workshop, Greenbelt, MD (USA), 18-21 Feb 1992
SO: PROCEEDINGS-OF-THE-OCEAN-CLIMATE-DATA-WORKSHOP. Churgin,-J.-comp. GREENBELT,-MD-USA NASA-GODDARD-SPACE-FLIGHT-CENT. 1993 pp. 51-64
LA: English
ER: M (Marine)
AB: The present program aimed at the study of ocean climate change is prepared by a group of scientists from State Oceanographic Institute, Academy of Science of Russia, Academy of Science of Ukraine and Moscow State University. It appears to be a natural evolution of ideas and achievements that have been developed under national and international ocean research projects such as SECTIONS, WOCE, TOGA, JGOFS and others. During last two decades main efforts were concentrated on quantitative experimental and model description of the ocean's role in the global climate change. In particular, the significance of the energy active zones of the ocean in the ocean-atmosphere interaction processes was defined; the connections between the sea surface temperature (SST) anomalies and the inter annual variations of the global atmosphere circulation were established; the stability of the meridianal ocean thermohaline circulation and it's influence on global climate was carefully concerned about. The derived results have proved the exclusively important role of the North Atlantic as a key feature in formation of the global "conveyor" of interoceanic circulation, which determines the long-period variability of the entire climate system.
AN: 3505288
162 of 200
TI: Response of biota to sedimentary organic matter quality of the West Gironde mud patch, Bay of Biscay (France)
AU: Relexans,-J.-C.; Lin,-R.G.; Castel,-J.; Etcheber,-H.; Laborde,-P.
AF: Lab. Oceanogr. Biol., Univ. Bordeaux 1, Ave. Facultes, 33405 Talence, France
SO: OCEANOL.-ACTA 1992 vol. 15, no. 6, pp. 639-649
LA: English
ER: M (Marine); B (Brackish)
AB: Relationships between benthos and sedimentary organic matter quality were analyzed in the West Gironde Mud Patch (WGMP), off the Gironde estuary, as part of the multidisciplinary national programme Ecomarge, a JGOFS-France contribution. The following parameters of the sediment were analyzed: POC (particulate organic carbon); sigma (sum of easily extractable macromolecules thought to be the most degradable part of particulate organic matter); pigments as indices of organic matter quality; ETS (electron-transport-system) activities and meiofauna densities as indices of benthic responses. Sediments from the WGMP have an overall low organic carbon content (0.8%); the labile organic fraction ( sigma ) does not exceed 10% of the total sedimentary POM (particulate organic matter). Nevertheless, the supply of freshly-formed matter was marked both by pigment and sigma increases, especially westwards. The distribution of meiofauna abundances did not follow the same gradients as pigments, ETS and sigma , and presumably depended on environmental factors other than those analyzed here.
AN: 3501355
163 of 200
TI: Measuring primary production at sea: Potential problem with 24-h incubations using the super(14)C method
AU: Legendre,-L.; Klein,-B.; Mingelbier,-M.; Tamigneaux,-E.
AF: GIROQ, Dep. Biol., Univ. Laval, PQ G1K 7P4, Canada
CO: Int. Symp. on Measurement of Primary Production from the Molecular to the Global Scale, La Rochelle (France), 21-24 Apr 1992
SO: MEASUREMENT-OF-PRIMARY-PRODUCTION-FROM-THE-MOLECULAR-TO-THE-GLOBAL-SCALE.-PROCEEDINGS-OF-A-SYMPOSIUM-HELD-IN-LA-ROCHELLE,-21-24-APRIL-1992. COPENHAGEN-DENMARK ICES 1993 vol. 197 p. 280
ST: ICES-MAR.-SCI.-SYMP. vol. 197
NT: Summary only.
LA: English
ER: M (Marine)
AB: In JGOFS Core measurement protocols, it is recommended that 24-h dawn-to-dusk incubations be conducted for estimating daily rates of primary production by the super(14)C method. However, given the constraints of navigation it is not always possible to start in situ or simulated in situ incubations at dawn, especially when an extensive grid of stations must be sampled. If phytoplankton production is estimated from changes in oxygen concentration in light and dark bottles, values should be the same irrespective of the time of the day the incubation started. This is not the case, however, if primary production is estimated from the uptake of super(14)C. Simulations of 24-h incubations and field experiments with natural phytoplankton populations show that the measured uptake of super(14)C can vary by up to 4-5 times depending on the time the incubation starts relative to sunrise. Both simulated and experimental data show lowest super(14)C accumulation in incubations starting at sunrise (i.e. dawn-dawn incubation), while highest values correspond to incubations beginning at sunset. When samples are collected during the night, incubations can be started immediately, but they should be conducted for a full 24-h period after dawn. On the other hand, samples collected after dawn should be incubated for 24 h, and the super(14)C accumulation values corrected in order to get dawn-to-dawn values.
AN: 3053678
164 of 200
TI: National Oceanographic Data Center inventory of physical oceanographic profiles. Global distributions by year for all countries
AU: Levitus,-S.; Gelfeld,-R.D.
AF: U.S. Natl. Oceanogr. Data Cent./World Data Cent.-A for Oceanogr., 1825 Connecticut Ave. N.W., Washington, DC 20235, USA
SO: KEY-OCEANOGR.-REC.-DOC. WASHINGTON-DC-USA NOAA 1992 no. 18, 242 pp
LA: English
ER: M (Marine)
AB: A critical requirement for climate and global change research is the availability of digital global oceanographic data covering long time periods. Substantial resources are being allocated for global ocean programs such as the Climate and Global Change, TOGA, WOCE, and JGOFS, and for the establishment of a Global Ocean Observing System (GOOS). It has been estimated that perhaps two-thirds of all global historical oceanographic data exist only in manuscript form in archives around the world, and thus effectively are not available to researchers and other users. To address this problem, the U.S. National Oceanographic Data Center (NODC)/World Data Center A for Oceanography (WDC-A) has begun an "Oceanographic Data Archaeology and Rescue" project. "Data archaeology" is the term used to describe the process of seeking out, restoring, evaluating, correcting, and interpreting historical data sets. Summarizing the data held in the world's maintained archives in digital form is a first step to allow researchers and data managers to know what data are available, where the gaps in data coverage are, and what data they have or have knowledge of that are not in these archives. The following data distribution plots have been prepared from the NODC and WDC-A archives through June 1992 as part of this initial step. These plots for Mechanical, Expendable, and Selected Level Bathythermograph Profiles, CTD/STD Profiles, and oceanographic Station Profiles have been prepared by yearly period.
AN: 3050748
165 of 200
TI: New production -- a new research area of oceanography
AU: Jiao,-Nianzhi; Wang,-Rong
AF: Inst. Oceanol., Acad. Sin., Qingdao 266071, People's Rep. China
SO: OCEANOL.-LIMNOL.-SIN.-HAIYANG-YU-HUZHAO 1993 vol. 24, no. 2, pp. 205-211
LA: Chinese
ER: M (Marine)
AB: Study of new production, as a new research area of marine biology and biological oceanography, including the concept, methods and related projects, is reviewed. super(15)N technique as the basic method to estimate new production is introduced. Other approaches (by sediment traps, "f" ratio, remote sensing, net oxygen production in the euphotic zone, super(234)Th residence time, current models, and flux models) are also reviewed. The Chinese national program "Ocean Flux Study in the Shelf Margin of the East China Sea" proposed by the Chinese JGOFS Committee and supported by the NNSFC (National Natural Science Foundation of China) implemented in 1992 has new production study as one of the most important projects.
AN: 3043885
166 of 200
TI: Determining primary production from the mesoscale oxygen field
AU: Emerson,-S.; Quay,-P.; Stump,-C.; Wilbur,-D.; Schudlich,-R.
AF: Sch. Oceanogr. WB-10, Univ. Washington, Seattle, WA 98195, USA
CO: Int. Symp. on Measurement of Primary Production from the Molecular to the Global Scale, La Rochelle (France), 21-24 Apr 1992
SO: MEASUREMENT-OF-PRIMARY-PRODUCTION-FROM-THE-MOLECULAR-TO-THE-GLOBAL-SCALE.-PROCEEDINGS-OF-A-SYMPOSIUM-HELD-IN-LA-ROCHELLE,-21-24-APRIL-1992. COPENHAGEN-DENMARK ICES 1993 vol. 197 pp. 196-206
ST: ICES-MAR.-SCI.-SYMP. vol. 197
LA: English
ER: M (Marine)
AB: Net biological oxygen production can be determined from models of time-series measurements of the oxygen field, so long as there are simultaneous measurements of inert gas tracers to estimate the role of air-water transfer and mixing with the ocean interior. In the two locations where this has been done, the oxygen balance yields net nutrient production values that are within a factor of three of sediment trap and in vitro incubation experiments. Initial findings from a similar study at the US JGOFS time-series station near Hawaii (Station ALOHA) reveal that nitrogen uptake determined by net biological O sub(2) production in the upper 175 m, which includes both the euphotic and shallow respiration zones, agrees to within a factor of two of the mean annual sediment trap N flux at 150 m. Poorly known processes that should be explored to reconcile differences in the various methods are: (a) transport of dissolved and suspended particulate organic matter out of the euphotic zone, (b) alteration of O sub(2):DIC:NO super(-) sub(3) stoichiometry in the euphotic zone by production of carbon-rich dissolved organic matter, and (c) bacterial heterotrophic NO super(-) sub(3) uptake.
AN: 3039046
167 of 200
TI: Bacterioplankton growth and DOC distribution in the Sargasso Sea and Central Equatorial Pacific Ocean
AU: Carlson,-C.A.; Ducklow,-H.W.
AF: Horn Point Environ. Lab., Cambridge, MD 21613, USA
CO: ASLO and SWS 1993 Annu. Meet., Edmonton, AB (Canada), 30 May-3 Jun 1993
SO: ASLO-AND-SWS-1993-ANNUAL-MEETING.-ABSTRACTS. USA ASLO-SWS 1993 vp
NT: Summary only.
LA: English
ER: M (Marine)
AB: The authors made seasonal measurements of dissolved organic carbon, bacterial abundance and production in the vicinity of the JGOFS BATS station in the western Sargasso Sea in 1991-92 and two 20-day time series of the same parameters at the JGOFS EqPac station, 0 N, 140 W in spring (El Nino) and fall (non-El Nino), 1992. DOC was measured by the high-temperature catalytic oxidation (HTCO) technique using a Dohrmann DC-190 with a LiCor CO sub(2) detector. DOC concentrations in the Sargasso varied from 84-55 mu M in the upper 250 m, with a subsurface maximum of amplitude 10 mu M at ca 20-60 m. In the Pacific, DOC was very uniform at 65-70 mu M in the mixed layer (0-80 m), declining to 45 mu M below 140 m. In both systems, bacterial production was positively correlated with DOC, including the subsurface maxima and other random features of the DOC profiles. DOC utilization was very slow in seawater cultures.
AN: 3020260
168 of 200
TI: Technology and related developments for interdisciplinary global studies
AU: Dickey,-T.D.
AF: Univ. Southern California, Univ. Park, Los Angeles, CA 90089, USA
SO: SEA-TECHNOL. 1993 vol. 34, no. 8, pp. 47-54
LA: English
ER: M (Marine)
AB: The term global change usually connotes climate change--a bias toward physical aspects. However, it involves considerably more diverse and complex set of scientific problems related to the biology and chemistry of our planet. For this reason, interdisciplinary research directed toward global scale problems has become the focus for many oceanographers recently. Major programs such as the Joint Global Ocean Flux Study (JGOFS) and the Global Ocean Ecosystem Dynamics (GLOBEC) programs are well underway. The U.S. components are primarily administered and funded by NSF with additional funds from agencies such as NOAA, NASA, ONR, DOE, and EPA. Both programs have international components and coordinating organizations critical to their success.
AN: 3013049
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TI: Transient variations in phytoplankton productivity at the JGOFS Bermuda time series station.
AU: Malone,-T.C.; Pike,-S.E.; Conley,-D.J.
AF: Univ. Maryland System, Cent. Environ. Estuar. Stud., Horn Point Environ. Lab., Cambridge, MD 21613, USA
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP.. 1993. vol. 40, no. 5, pp. 903-924
LA: English
ER: M (Marine)
AB: Time series of 13 days in August and 18 days in March-April reveal high variability in phytoplankton productivity on a time scale of days. Specific growth rates were also variable, ranging from 0.1 to 0.7/day in August and from <0.10 to 1.3/day in March-April. Picoplankton accounted for most productivity and biomass in the mean. Pigment markers suggest that Synechococcus and prochlorophytes dominated the picoplankton in the surface layer and the chlorophyll maximum, respectively. Phytoplankton respectively accounted for an average of 7% and 8% of particulate organic matter in the surface mixed layer and bottom layer of the euphotic zone in the August time series, compared to 11% and 21% in the March-April time series. Biomass peaks were associated with increases in prochlorophytes, prymnesiophytes and diatoms during both time series. Passage of Hurricane Dean at the beginning of the August time series had little impact on euphotic zone chlorophyll, but productivity declined by 70%. The subsequent increase in productivity was initiated by an increased growth rate in the mixed layer followed by a nitrate-dependent increase in growth rate in the bottom layer of the euphotic zone. Variations in productivity during the March time series were related to incident radiation and to changes in biomass as different water masses moved through the region. Nitrate flux and productivity were closely coupled during the August time series and uncoupled during the March time series.
AN: 2996778
170 of 200
TI: Zooplankton biomass and grazing at the JGOFS Sargasso Sea time series station.
AU: Roman,-M.R.; Dam,-H.G.; Gauzens,-A.L.; Napp,-J.M.
AF: Horn Point Environ. Lab., Cent. Environ. Estuar. Stud., Univ. Maryland System, P.O. Box 775, Cambridge, MD 21613, USA
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP.. 1993. vol. 40, no. 5, pp. 883-901
LA: English
ER: M (Marine)
AB: We examined the variability in zooplankton biomass and grazing in the upper 200 m at the JGOFS time series station off Bermuda during 3 week periods in August 1989 and in March/April 1990. The average-integrated >64 mu m zooplankton biomass was similar in August (571 mg C m super(-2)) and March/April (592 mg C m super(-2)). However, macrozooplankton (>200 mu m) represented a greater portion of total (>64 mu m) zooplankton biomass in March/April (75%) as compared to August (30%). The average estimated rate of phytoplankton ingestion was higher in March/April (3.7 mg C m super(-2) h super(-1)) compared to August (0.6 mg C m super(-2) h super(-1)), with macrozooplankton (>200 mu m) contributing more to the estimated flux in March (65%) compared to August (14%). Our estimates of 3 times greater macrozooplankton biomass in March/April is similar in magnitude to the differences in the estimated flux of organic material from the photic zone during these seasons. In addition, short-term changes in the sinking of particulate organic matter during our March/April cruise were consistent with increases/decreases in macrozooplankton biomass and grazing.
AN: 2996777
171 of 200
TI: Methodology for oceanic CO sub(2) measurements. Final report of SCOR Working Group 75.
CA: UNESCO, Paris (France)
SO: UNESCO-TECH.-PAP.-MAR.-SCI. 1992. no. 65, 42 pp
NT: Also avail. in Ru.
LA: English
ER: M (Marine)
AB: This report summarizes the results of the deliberations of the SCOR Working Group 75 on methodology for oceanic CO sub(2) measurements at meetings in Hamburg (1983), Lake Arrowhead (1984), Les Houches (1985) and Woods Hole (1988). It reviews the scientific and technical basis for oceanic studies: measuring equipment, procedures, ocean carbon standards and intercalibration. The report describes the state-of-the-art methodology and recommends a program dedicated to determining the diurnal, seasonal and interannual variability of the oceanic carbon cycle. The framework of a global CO sub(2) survey as an international effort is adopted by JGOFS (Joint Global Ocean Flux Study) in the world hydrographic program of WOCE (World Ocean Circulation Experiment).
AN: 2990211
172 of 200
TI: An autumn cruise to Antarctica.
AU: Lutjeharms,-J.R.E.; Lucas,-M.I.
AF: Ocean Climatol. Res. Group, Dep. Oceanogr., Univ. Cape Town, Rondebosch, 7700 South Africa
CA: SANARP, Cape Town (South Africa)
SO: S.-AFR.-J.-SCI.-S.-AFR.-TYDSKR.-WET. 1993. vol. 89, no. 2, pp. 60
LA: English
ER: M (Marine)
AB: On 27 March 1992, the German research ship and icebreaker, the Polarstern, left Cape Town with 51 scientists and technicians from 12 countries on board to study the coastal waters off Antarctica. Called Herbst im Eis (Autumn in the Ice), this expedition had as its main aim an investigation of the physics, chemistry, biota and their respective processes as the winter ice was forming. Such a study at this time of year requires a research platform of some sophistication and with icebreaking capability. Few such vessels exist, so such a study has till now not been attempted. Results from this expedition will take a number of years to be calibrated, correlated, subjected to critical review and published. Even at this early stage, however, it is clear that a considerable advance has been made towards the scientific understanding of this region and about processes that occur as the ice forms. A major contribution has also been made towards the aims of international research programs such as WOCE (World Ocean Circulation Experiment) and JGOFS (Joint Global Ocean Flux Study).
AN: 2989512
173 of 200
TI: Effect of selected calculation routines and dissociation constants on the determination of total carbon dioxide in seawater.
AU: Stoll,-M.H.C.; Rommets,-J.W.; De-Baar,-H.J.W.
AF: Netherlands Inst. Sea Res., P.O. Box 59, 1790 AB Den Burg, Texel, Netherlands
SO: DEEP-SEA-RES.-1-OCEANOGR.-RES.-PAP.. 1993. vol. 40, no. 6, pp. 1307-1322
LA: English
ER: M (Marine)
AB: During the 1989 and 1990 JGOFS North Atlantic Pilot Study a comparison was made between the Coulometric and the acid titration method for determination of total carbon dioxide (TCO sub(2)) in seawater. TCO sub(2) and alkalinity have been calculated from acid titration using either the modified Gran plot or the curve-fitting routine. Depth profiles showed fair agreement (on average 0.6% or about 12.5 mu mol) between the TCO sub(2) calculated from the acid titration method and the TCO sub(2) measured independently by Coulometry. It is shown that different data processing routines combined with the proper use of dissociation constants can influence the acid titration result considerably. There appears to be a slight offset between calculated and Coulometric data which is smallest when using the combined dissociation constants of Hansson with Goyet and Poisson. No statistically significant difference could be found between the two used calculation methods (Gran plot and curve-fitting). The agreement between the independent methods of Coulometry and acid titration is encouraging and furthermore independent of depth, for this dataset there is no reason for invoking the existence of interfering (organic) protolytes.
AN: 2989135
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TI: The spatial and temporal development of the spring bloom during the JGOFS North Atlantic Bloom Experiment, 1989.
AU: Weeks,-A.R.; Fasham,-M.J.R.; Aiken,-J.; Harbour,-D.S.; Read,-J.F.; Bellan,-I.
AF: Dep. Oceanogr., Univ. Southampton, Southampton SO9 5NH, UK
SO: J.-MAR.-BIOL.-ASSOC.-U.K. 1993. vol. 73, no. 2, pp. 253-282
LA: English
ER: M (Marine)
AB: The south to north development of the spring bloom in the North Atlantic Ocean was observed during four cruises from April to August 1989. Transects with towed undulating instrumentation packages and CTD profiles on station were made between 42 degree N and 54 degree N, along 17 degree W and 20 degree W in April and between 47 degree N and 60 degree N along 20 degree W in May, June and July/August, giving vertical sections of temperature and chlorophyll concentration derived from in vivo fluorescence. These sections show the relationship between the onset of seasonal stratification and the initiation of the spring bloom. Supporting data from microscopic analysis of the major phytoplankton species show that the seasonal succession commenced with diatoms, followed in turn by coccolithophores, flagellates and dinoflagellates. During the development of summer stratification the mesoscale distribution of chlorophyll was strongly determined by the depth of the mixed layer, but once stratification had been firmly established higher chlorophyll values tended to be found within the warmer eddies (meanders). One possible explanation of this result is that phytoplankton growth is higher in the warmer eddies.
AN: 2960645
175 of 200
TI: Evidence for dependency of bacterial growth on enzymatic hydrolysis of particulate organic matter in the mesopelagic ocean.
AU: Hoppe,-H.-G.; Ducklow,-H.; Karrasch,-B.
AF: Inst. Meereskd., Duesterbrooker Weg 20, D-W 2300 Kiel 1, FRG
SO: MAR.-ECOL.-PROG.-SER. 1993. vol. 93, no. 3, pp. 277-283
NT: Bibliogr.: 43 ref.
LA: English
ER: M (Marine)
AB: Organic material entering the oceanic mesopelagic zone may either reenter the euphotic zone or settle into deeper waters. Therefore it is important to known about mechanisms and efficiency of substrate conversion in this water layer. Bacterial biomass, bacteria secondary production (BSP), extracellular peptidase activity (EPA) and particulate organic nitrogen (PON) were measured in vertical profiles of the North Atlantic (46 degree N 18 degree W; 57 degree N 23 degree W) during the Joint Global Ocean Flux Study (JGOFS) cruise in May 1989. The magnitude of these parameters decreased differently with depth. The strongest decreases were observed for bacterial production ( super(3)H-thymidine incorporation) and peptide turnover (using the substrate analog leucine-methylcoumarinylamide). Bacterial biomass and peptidase potential activity were not reduced as much in the mesopelagic zone. Peptidase potential per unit cell biomass of mesopelagic bacteria was 2 to 3 times higher than that of bacteria in surface water. Nevertheless bacteria growth at depth was slow, due to slow actual hydrolysis.
AN: 2953830
176 of 200
TI: Twentieth General Meeting of the Scientific Committee on Oceanic Research (SCOR).
CO: 20. Gen. Meet. of the Scientific Comm. on Oceanic Research, Warnemuende (FRG), 1-5 Oct 1990
SO: OCEANOL.-ACAD.-SCI.-USSR. 1991. vol. 31, no. 2, pp. 249-251
LA: English
ER: M (Marine)
AB: SCOR is a scientific consultative committee of the International Council of Scientific Unions (ICSU), and it interacts with all known international organizations dealing with the study and utilization of the oceans; 38 countries are now SCOR members. Results obtained since the 19th central meeting by the constituent scientific working groups and national committees and by the programs and organizations under SCOR's aegis or cooperating with it in various areas of oceanology were reported, and plans and measures for improving the effectiveness of SCOR's work in the upcoming period were proposed. Two new national oceanographic committees, those of Korea and Pakistan, were inducted into SCOR. There were 16 scientific working groups. Such programs as CCCO, JGOFS, WOCE, TOGA, and the like that are being created within SCOR to address fundamental large-scale or global problems are the most significant, although also the most toilsome, results of SCOR's activity.
AN: 2886495
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TI: Total dissolved nitrogen and phosphorus concentrations at US-JGOFS Station ALOHA: Redfield reconciliation.
AU: Karl,-D.M.; Tien,-G.; Dore,-J.; Winn,-C.D.
AF: Univ. Hawaii, SOEST/Biol. Oceanogr. Div., 1000 Pope Rd., Honolulu, HI 96822, USA
CO: Workshop on the Measurement of Dissolved Organic Carbon and Nitrogen in Natural Waters, Seattle, WA (USA), 15-19 Jul 1991
SO: MEASUREMENT-OF-DISSOLVED-ORGANIC-CARBON-AND-NITROGEN-IN-NATURAL-WATERS. Hedges,-J.I.;Lee,-C.-eds. 1993. vol. 41, no. 1-3 pp. 203-208
ST: MAR.-CHEM. vol. 41, no. 1-3
LA: English
ER: M (Marine)
AB: Twenty-two water column profiles (0-4500 m) of total dissolved nitrogen (TDN) and phosphorus (TDP) concentrations have been collected over a 2-year period at the US-JGOFS time-series Station ALOHA. These data indicate that the N:P molar ratio (mean, 16.74; standard deviation, 2.95; n = 417) in the central Pacific Ocean is not significantly different from that predicted a priori based upon current models of the bioelemental composition of plankton. An examination of the literature and new data from our laboratory using direct high-temperature combustion methods for both TDP and TDN support the validity of historical oceanic analyses. Despite the substantially higher DOC values in oligotrophic Pacific Ocean surface waters, TDN (and consequently dissolved organic nitrogen (DON)) and TDP (and consequently dissolved organic phosphorus (DOP)) do not appear to have been underestimated.
AN: 2885885
178 of 200
TI: Notes on the JGOFS North Atlantic Bloom Experiment -- dissolved organic carbon intercomparison.
AU: Fitzwater,-S.E.; Martin,-J.H.
AF: Moss Landing Mar. Lab., P.O. Box 450, Moss Landing, CA 95039, USA
CO: Workshop on the Measurement of Dissolved Organic Carbon and Nitrogen in Natural Waters, Seattle, WA (USA), 15-19 Jul 1991
SO: MEASUREMENT-OF-DISSOLVED-ORGANIC-CARBON-AND-NITROGEN-IN-NATURAL-WATERS. Hedges,-J.I.;Lee,-C.-eds. 1993. vol. 41, no. 1-3 pp. 179-185
ST: MAR.-CHEM. vol. 41, no. 1-3
LA: English
ER: M (Marine)
AB: Using high temperature catalytic oxidation (HTCO), personnel from four laboratories analyzed water samples collected during the JGOFS North Atlantic Bloom study for their dissolved organic carbon (DOC) content. In general, good agreement was obtained. Values obtained on samples filtered and frozen compared well with those analyzed immediately after collection. DON analyses of the same frozen samples did not co-vary with DOC; thus far, DON results have only been reported by Moss Landing Marine Laboratories.
AN: 2885817
179 of 200
TI: Sea-trials of three different methods for measuring non-volatile dissolved organic carbon in seawater during the JGOFS North Atlantic pilot study.
AU: Baar,-H.J.W.-de; Brussaard,-C.; Hegeman,-J.; Schijf,-J.; Stoll,-M.H.C.
AF: Netherlands Inst. Sea Res. (NIOZ), P.O. Box 59, 1790 AB Den Burg, Netherlands
CO: Workshop on the Measurement of Dissolved Organic Carbon and Nitrogen in Natural Waters, Seattle, WA (USA), 15-19 Jul 1991
SO: MEASUREMENT-OF-DISSOLVED-ORGANIC-CARBON-AND-NITROGEN-IN-NATURAL-WATERS. Hedges,-J.I.;Lee,-C.-eds. 1993. vol. 41, no. 1-3 pp. 145-152
ST: MAR.-CHEM. vol. 41, no. 1-3
LA: English
ER: M (Marine)
AB: In 1989 the shipboard comparison of three different methods for measuring concentrations of dissolved organic carbon (DOC) resulted in reasonable agreement, with differences likely as a result of a combination of calibration offsets and general instability of the instruments at sea. Typical concentrations were about 80-140 mu mol in the upper 1000 m of the water column, with a tendency towards higher values (100-150 mu mol) in the surface waters. These elevated surface water levels are below the 200-300 mu mol values recently reported for the Atlantic and the Pacific Oceans. In 1990 the small dataset obtained with a further modified High Temperature Combustion instrument showed similar trends. Within the analytical error there is no significant offset between two HTCO methods and one wet oxidation technique.
AN: 2885710
180 of 200
TI: Carbon and nitrogen export during the JGOFS North Atlantic Bloom Experiment estimated from super(234)Th: super(238)U disequilibria.
AU: Buesseler,-K.O.; Bacon,-M.P.; Cochran,-J.K.; Livingston,-H.D.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: DEEP-SEA-RES. 1992. vol. 39, no. 7-8A, pp. 1115-1137
LA: English
ER: M (Marine)
AB: The disequilibrium between the particle-reactive tracer super(234)Th (t sub(1/2) = 24.1 days) and its soluble parent, super(238)U, was used to examine Th scavenging and export fluxes during the U.S. JGOFS North Atlantic Bloom Experiment (24 April-30 May 1989) at similar to 47 degree N, 20 degree W. Four profiles of dissolved and particulate super(234)Th in the upper 300 m and a non-steady state box model were used to quantify dissolved super(234)Th uptake and particle export rates. The highest export fluxes occurred during the first half of May. From POC/ super(234)Th and PON/ super(234)Th ratios, particulate organic C and N fluxes were calculated. Results were 5-41 mmol C m super(2)/day and 0.9-6.5 mmol N m super(-2)/day from the 0-35 m layer. The ratio of POC export flux to primary production ranged from 0.05 to 0.42, peaking in the first half of May. The estimated fluxes agree with the observed losses of total C and N from the upper ocean during the bloom, but yield significantly higher fluxes than were measured by floating traps at 150 and 300 m.
AN: 2866040
181 of 200
TI: Seasonal variability in primary production and particle flux in the northwestern Sargasso Sea: U.S. JGOFS Bermuda Atlantic Time-Series Study.
AU: Lohrenz,-S.E.; Knauer,-G.A.; Asper,-V.L.; Tuel,-M.; Michaels,-A.F.; Knap,-A.H.
AF: Univ. Southern Mississippi, Cent. Mar. Sci., Stennis Space Cent., MS 39529, USA
SO: DEEP-SEA-RES. 1992. vol. 39, no. 7-8A, pp. 1373-1391
LA: English
ER: M (Marine)
AB: The relationship between primary production and sediment trap-derived downward flux of particulate organic matter was characterized over a 2 year period at the U.S. JGOFS Bermuda Atlantic Time-series Study (BATS) site to evaluate the importance of temporal variations in upper ocean biogeochemical processes. Water column-integrated primary production ( integral of PP), determined once each cruise using super(14)C incubations (in situ dawn-to-dusk), peaked in late winter/early spring of both 1989 and 1990. Smaller increases in integral of PP also occurred in July 1989 and October-December 1990. Annual integral of PP was 9.2 mol C m super(-2)/y in 1989 and 12 mol C m super(-2)/y in 1990. This was higher than the 1959-1963 annual average (6.8 mol C m super(-2)/y) determined at Station "S" located approximately 50 km northwest of the BATS site.
AN: 2865866
182 of 200
TI: Update: Joint Global Ocean Flux Study.
SO: SEA-TECHNOL. 1993. vol. 34, no. 1, pp. 49-53
LA: English
ER: M (Marine)
AB: Rising concern over the fate of carbon dioxide and other gases released into the atmosphere through human activities has sharpened scientific interest in the role of the ocean in the global flux of carbon. At the same time, the rapid development of methods for observing the transformations of carbon in the ocean is making it possible to undertake long-term studies on a global scale. JGOFS, a decade-long investigation, builds on knowledge of ocean processes to increase our understanding of the carbon cycle, its sensitivity to changes, and CO sub(2) exchange between the ocean and atmosphere.
AN: 2854593
183 of 200
TI: The carbon balance during the 1989 spring bloom in the North Atlantic Ocean, 47 degree N, 20 degree W.
AU: Bender,-M.; Ducklow,-H.; Kiddon,-J.; Marra,-J.; Martin,-J.
AF: Grad. Sch. Oceanogr., Univ. Rhode Island, Kingston, RI 02881, USA
SO: DEEP-SEA-RES. 1992. vol. 39, no. 10A, pp. 1707-1725
LA: English
ER: M (Marine)
AB: The authors report on studies of the carbon balance of the upper water column, done as part of the JGOFS North Atlantic Bloom Experiment, over a 13-day period, at 47 degree N, 20 degree W, during the 1989 spring phytoplankton bloom. Gross carbon production was calculated from data on super(18)O gross O sub(2) production and from super(14)C production as well. Net carbon production was calculated from net O sub(2) production rates measured in vitro, as well as from changes in the inventories of nutrients and O sub(2) along with O sub(2) evasion rates by gas exchange. Gross carbon production during this period was measured to be 1.83 mol m super(-2), and net production was 0.68 mol m super(-2). Of this net carbon production, 0.30 mol m super(-2) was stored in the euphotic zone as particulate organic carbon, and 0.09 mol m super(-2) rained out to depths > 150 m. The remainder was remineralized to DIC in the 50-150 m depth interval, with perhaps some DOC storage in the upper 150 m.
AN: 2854524
184 of 200
TI: US Joint Global Ocean Flux Study program.
SO: OCEANUS. 1992. vol. 35, no. 1, pp. 57-59
NT: Spec. iss.: Marine Chemistry.
LA: English
ER: M (Marine)
AB: The ocean's role in the global carbon cycle has attracted the interest of scientists from diverse disciplines for more than half a century, an interest sharpened in recent years by concerns about the effects of human activity upon atmospheric levels of carbon dioxide (CO sub(2)) and other greenhouse gases. The Joint Global Ocean Flux Study (JGOFS) builds on accumulated knowledge about the ocean's chemical, biological, and physical processes to increase understanding of the ocean carbon cycle. The program has two primary goals: to determine at a global level the processes that control the movement of carbon and other biologically active elements in the ocean and the way this cycling interacts with the atmosphere, the ocean margins, and the seafloor; and to improve our ability to make global-scale predictions of the likely response of ocean processes to changes in climate associated with human activities.
AN: 2837593
185 of 200
TI: Zooplankton community respiration during the JGOFS pilot study.
AU: Martens,-P.
AF: Biol. Anst. Helgoland, Wattenmeerstn. Sylt, D-W 2282 List, FRG
SO: HELGOL.-MEERESUNTERS. 1992. vol. 46, no. 2, pp. 117-135
NT: Bibliogr.: 26 ref.
LA: English
ER: M (Marine)
AB: From March to July 1989 (JGOFS pilot study), measurements were carried out on the oxygen uptake of natural zooplankton communities on five drifting stations (about three weeks each) in the Atlantic from 18 degree N to 72 degree N after a method of Martens (1986). The weight specific respiration rate decreased from south to north parallel to the water temperature, whereas then amount of mesozooplankton increased. No significant differences in the oxygen uptake of the zooplankton community between the five stations could be found. A rough estimate showed that less than 2% of the phytoplankton carbon was assimilated by the mesozooplankton per day. This is thought to reflect a typical spring situation. The weight specific respiration rate is influenced significantly by the water temperature and the mean length of the zooplankter.
AN: 2826608
186 of 200
TI: Airborne Oceanographic Lidar participation in the US Joint Global Ocean Flux Study (JGOFS).
AU: Hoge,-F.E.; Swift,-R.N.
CA: National Aeronautics and Space Adm., Wallops Island, VA (USA). Wallops Flight Cent.
CO: 4. NASA Airborne Geoscience Workshop, Washington, DC (USA), 1991
SO: 1991. 1 p
NT: NTIS Order No: N91-25468/0/GAR Summary only.
LA: English
AB: The U.S. JGOFS is part of a major international field experiment which the National Science Foundation (NSF) is conducting during the decade. It will combine ship and aircraft data collected in both the Atlantic and Pacific oceans. The primary data collected by the Airborne Oceanographic Lidar (AOL) is laser-induced chlorophyll fluorescence together with the concurrent laser-induced water Raman backscatter and phycoerythrin fluorescence. Passive solar-induced up-welling radiances and down-welling solar irradiance are also acquired. Results from the 1989 Atlantic mission as well as plans for use of the new long-range Wallops P-3 during the upcoming Equatorial Pacific mission are presented.
AN: 2797113
187 of 200
TI: Aircraft remote sensing of phytoplankton spatial patterns during the 1989 Joint Global Ocean Flux Study (JGOFS) North Atlantic Bloom Experiment.
AU: Yoder,-J.A.; Hoge,-F.E.
CA: National Aeronautics and Space Adm., Greenbelt, MD (USA). Goddard Space Flight Cent.
CO: 4. NASA Airborne Geoscience Workshop, Washington, DC (USA), 1991
SO: 1991. 1 p
NT: NTIS Order No: N91-25493/8/GAR. Summary only.
LA: English
ER: M (Marine)
AB: Mesoscale phytoplankton chlorophyll variability near the Joint Global Ocean Flux Study sites along the 20 W meridian at 34 N, 47 N, and 59 N is discussed. The NASA P-3 aircraft and the airborne oceanographic lidar (AOL) system provides remote sensing support for the North Atlantic Bloom Experiment. The principal instrument of the AOL system is the blue-green laser that stimulates fluorescence from phytoplankton chlorophyll, the principal photosynthetic pigment. Other instruments on the NASA P-3 aircraft include up- and down-looking spectrometers, PRT-5 for infrared measurements to determine sea surface temperature, and a system to deploy and record AXBTs to measure subsurface temperature structure.
AN: 2797111
188 of 200
TI: Surface chlorophyll concentration in the Tropical Pacific Ocean: An analysis of data collected by merchant ships from 1978 to 1989.
AU: Dandonneau,-Y.
AF: ORSTOM, Lab. Oceanogr. Dyn. et Climatol., Univ. Paris VI, Paris, France
SO: J.-GEOPHYS.-RES.-C-OCEANS. 1992. vol. 97, no. C3, pp. 3581-3591
LA: English
ER: M (Marine)
AB: The time and space variations of the chlorophyll concentration at the surface of the Tropical Pacific are examined from 1978 to 1989, on the basis of an extensive sampling carried out in cooperation with the crews of merchant ships. The data are distributed into three sets, which correspond to shipping tracks from New Caledonia to Panama, to North America, or to Japan. The data are log-transformed, and an empirical orthogonal function (EOF) analysis is applied. The first EOF has a uniform eigenvector (spatial pattern) and extracts about 50% of the total variance. In the central and western Pacific, the second, third and fourth EOFs correspond respectively to the equatorial upwelling, to a north-south balance centered at the equator, and to phenomena which produce maxima at 5 degree N or 5 degree S, probably related to the equatorial countercurrents. In the eastern Pacific the second EOF seems to account for the meridional displacements of the thermal front located near the Galapagos Islands. The multiyear variations caused by the El Nino - Southern Oscillation dominate most EOF time functions. Weak seasonal variations are sometimes suggested by these time functions. The results from the EOF analysis are used to reconstruct a tentative, unbiased chlorophyll field from 1979 to 1989.
AN: 2791167
189 of 200
TI: Introduction to the WEC88 cruise: An investigation into why the Equator is not greener.
AU: Barber,-R.T.
AF: Duke Univ. Mar. Lab., Beaufort, NC 28516, USA
SO: J.-GEOPHYS.-RES.-C-OCEANS. 1992. vol. 97, no. C1, pp. 609-610
LA: English
ER: M (Marine)
AB: This issue of the Journal of Geophysical Research contains seven papers that describe results from cruise WEC88 of R/V Wecoma , which worked in the equatorial Pacific in February and March 1988. The name of the cruise was WEC88. The research plan for this cruise was based on the evolving understanding of the regulation of biological productivity in equatorial waters. The cruise left Honolulu on February 15, and at 15 degree N latitude began a transequatorial section on 150 degree W longitude. The cruise occupied 21 stations between 15 degree N and 15 degree S, and 6 days were spent at a time series station on the equator. "Why isn't the equator greener?" was the central question WEC88 addressed, but work on the cruise focused on a particular subset of the relevant hypotheses dealing with the connection between regulation of physiological processes of phytoplankton and ambient light, nutrient, and physical conditions. These papers played a role in shaping the design of the Joint Global Ocean Flux Study (JGOFS) in the Equatorial Pacific. Together they provide a detailed interdisciplinary description of the interaction of phytoplankton processes and environmental conditions of the equatorial Pacific.
AN: 2790951
190 of 200
TI: Precision of estimates of phytoplankton growth and microzooplankton grazing when the functional response of grazers may be nonlinear.
AU: Evans,-G.T.; Paranjape,-M.A.
AF: JGOFS-Buero, Inst. Meereskd., Duesternbrooker Weg 20, D-W 2300 Kiel 1, FRG
SO: MAR.-ECOL.-PROG.-SER. 1992. vol. 80, no. 2-3, pp. 285-290
NT: Bibliogr.: 25 ref.
LA: English
ER: M (Marine)
AB: The analysis of dilution experiments for determining rates of phytoplankton growth and microzooplankton grazing needs to be reconsidered. Zooplankton grazing may saturate at high food concentrations, and therefore experimental data should be fitted with models that include this possibility. Such models will fit the data better; as a consequence, they will reveal some of the uncertainty in the rate estimates that linear analysis conceals. We illustrate this point with simulated and real dilution experiments.
AN: 2752761
191 of 200
TI: Continuous micro-flow analyzers, labs are seaworthy shipmates.
AU: Iervolino,-L.
AF: Bran + Luebbe GmbH, Netherlands
SO: SEA-TECHNOL. 1992. vol. 33, no. 2, pp. 64-68
LA: English
ER: M (Marine)
AB: Dutch researchers convert shipping containers to seagoing laboratories for JGOFS, WOCE studies in North Atlantic.
AN: 2741598
192 of 200
TI: Preliminary sedimentological characterisation of the EUMELI project sites (JGOFS-France).
OT: Caracterisation sedimentologique preliminaire des sites du projet EUMELI (JGOFS-France)
CA: Association des Sedimentologistes Francais, Paris (France)
CO: 3. Congr. Francais de Sedimentologie, Brest (France), 1991
SO: THIRD-FRENCH-SYMPOSIUM-OF-SEDIMENTOLOGY:-T1-ABSTRACTS,-T2-TRIPS;-BREST,-PALAIS-DE-CONGRES,-18-19-20-NOVEMBER-1991.. 3e-CONGRES-FRANCAIS-DE-SEDIMENTOLOGIE:-T1-LIVRE-DE-RESUMES,-T2-LIVRE-DES-EXCURSIONS;-BREST,-PALAIS-DES-CONGRES,-18-19-20-NOVEMBRE-1991. 1991. pp. 13-14
NT: 2 Vol. XIV-295, 160 pp. Only the Tome 1 (295 pp) is cited by ASFA.
LA: French
ER: M (Marine)
AB: One objective of the international program JGOFS (Joint Global Oceans Fluxes Study) is the evaluation at a global scale of particulate matter fluxes from production in the ocean surface layer to burial into the sediment historical record. Only in sites where a pelagic sedimentation regime prevails, can we expect to be able to model the complexity of the numerous biogeochemical processes involved. In this context we present a preliminary sedimentological description of the EUMELI project sites.
AN: 2728982
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TI: Examining several Southern Ocean data sets.
AU: McClain,-C.R.; Koblinsky,-C.J.; Firestone,-J.; Darzi,-M.; Yeh,-Eueng-Nan; Beckley,-B.D.
AF: Code 971, NASA Goddard Space Flight Cent., Greenbelt, MD 20771, USA
SO: EOS.-TRANS.-AM.-GEOPHYS.-UNION. 1991. vol. 72, no. 33, vp
LA: English
ER: M (Marine)
AB: The Southern Hemisphere ocean covers approximately 45% of the Earth's surface and poses a major scientific challenge to initiatives such as the World Ocean Circulation Experiment (WOCE) and the Joint Global Ocean Flux Study (JGOFS) programs, whose goals include elucidation of its deep circulation and its contributions to global biogeochemical budgets. The Southern Ocean is generally regarded as the region south of about 30 degree S and, in many respects, is quite different from its northern counterpart. Unlike the oceanic and atmospheric flows in the Northern Hemisphere, the Circumpolar Current and surface winds have relatively unobstructed circulations around Antarctica that allow the exchange of water between basins and result in the most intense wind forcing in the global ocean.
AN: 2699826
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TI: Development and assessment of an analytical system for the accurate and continual measurement of total dissolved inorganic carbon.
AU: Robinson,-C.; Williams,-P.J.-leB.
AF: University Coll. North Wales, Sch. Ocean Sci., Menai Bridge LL59 5EY, UK
SO: MAR.-CHEM. 1991. vol. 34, no. 3-4, pp. 157-175
LA: English
ER: M (Marine)
AB: An automated coulometric titration system based on that described by Johnson, Sieburth, Williams and Brandstrom (1987, Mar. Chem., 21: 117-133) has been evolved for the accurate and continual measurement of total dissolved inorganic carbon (TCO sub(2)). The instrument achieves an analytical precision (1 SD) of plus or minus 0.5-1.0 mu mol/kg (0.025-0.05%). The accuracy of the system has been examined by a limited comparison with other coulometric-based titrators and with a manometric-based system; agreement was to 1 mu mol/kg. The capability for automatic continual analysis allows surface mapping of TCO sub(2); a sample rate of 10 analyses/h gives a mapping resolution of 102 km. Provision for frequent standardization with a liquid substandard has been included in the development. The ability to achieve high-density analyses while maintaining interlaboratory consistency and standardization constitutes a vital contribution to surveys of ocean carbon chemistry (e.g. Joint Global Ocean Flux Study (JGOFS), World Ocean Circulation Experiment (WOCE)).
AN: 2620475
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TI: (Eastern Atlantic '90 Expedition, (R/V Meteor ) Cruise No. 12, 13th March to 30 June 1990.).
OT: Ostatlantik '90--Expedition, (F/S Meteor ) Reise Nr. 12, 13. Maerz-30. Juni 1990
AU: Wefer,-G.; Weigel,-W.; Pfannkuche,-O.
AF: Geowiss., Univ. Bremen, Postfach 330440, D-W2800 Bremen 33, FRG
SO: METEOR-BER. 1991. no. 1, 166 pp
NT: 25 ref.
LA: German
ER: M (Marine)
AB: The R/V Meteor Cruise No. 12 in the East Atlantic was divided up into 3 legs. During the first leg, trace metal concentration were determined at 4 stations as a base line study within the framework of the IOC-Program GIPME (Global Investigation of Pollution in the Marine Environment). During the second leg, geophysical and petrological investigations were carried out in the area of the Great Meteorbank, the Atlantis Seamount, and the Atlantis Fracture Zone. On the third leg, from Las Palmas to Hamburg, the work of the BIOTRANS and JGOFS programs were continued in the West European Basin.
AN: 2611616
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TI: How plankton change the climate (JGOFS).
AU: Williamson,-P.; Gribbin,-J.
AF: Plymouth Mar. Lab., Citadel Hill, Plymouth PL1 2PB, UK
SO: NEW-SCI. 1991. vol. 129, no. 1760, pp. 48-52
LA: English
ER: M (Marine)
AB: The oceans store about 50 times more carbon than the air, and, each year, oceans and atmosphere exchange around 15 times as much carbon dioxide as human activities produce. To predict how carbon dioxide will build up in future, and, in turn, understand changes in the climate, we need to understand how the ocean carbon cycle works. This is the aim of the Joint Global Ocean Flux Study (JGOFS), a 10-year programme that forms the main project in the International Geosphere Biosphere Programme, which investigates environmental change on a world scale. JGOFS oceanographers, biologists and chemists investigated the North Atlantic in 1989 to find out more about how and why plankton grow, what then happens to the carbon that they fix in their tissue, and what effect these organisms have on the exchange of carbon dioxide between air and sea. One target was to find out exactly what happens in the spring, when vast numbers of phytoplankton "bloom" across the oceans over a few weeks. Researchers were particularly interested in measuring the partial pressure of carbon dioxide at the surface of the sea.
AN: 2544964
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TI: Cruise report: JGOFS Leg 1. International study of the North Atlantic bloom. R/V Atlantis II voyage: 119.2 Funchal to Reykjavik, March/April 1989.
AU: Honjo,-S.; Manganini,-S.J.; Krishfield,-R.
CA: Woods Hole Oceanographic Inst., MA (USA)
SO: TECH.-REP.-WOODS-HOLE-OCEANOGR.-INST. 1989. 33 pp
NT: NTIS Order No.: PB90-240284/GAR.
RN: WHOI-89-22 (WHOI8922)
LA: English
ER: M (Marine)
AB: With the support of the National Science Foundation, the authors have completed the first cruise devoted to the GOFS and JGOFS program for the North Atlantic Bloom studies between Mar 28 and Apr 6 on board R/V Atlantis II . The major task of this cruise, to deploy bottom-tethered mooring arrays with time-series sediment traps along with current meters at two critical stations, 34 deg N and 47 deg N along 20 deg W, was accomplished. All 6 sediment traps, 3 on each array, were set at 14-day intervals for 13 periods from Apr 3 to Sep 26, 1989. Their opening and closing times were synchronized throughout the period of deployment. The arrays and instruments will be recovered and redeployed in Sep/Oct, 1989. Ancillary water column data, such as CTD, fluorometry, pigments, and major nutrient distribution, were also successfully completed. (Grant NSF-OCE88-14228. Sponsored by National Science Foundation, Washington, DC.)
AN: 2541146
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TI: Grazing of copepod assemblages in the north-east Atlantic: The importance of the small size fraction.
AU: Morales,-C.E.; Bedo,-A.; Harris,-R.P.; Tranter,-P.R.G.
AF: Plymouth Mar. Lab., Prospect Place, West Hoe, Plymouth PL1 3DH, UK
SO: J.-PLANKTON-RES. 1991. vol. 13, no. 2, pp. 455-472
LA: English
ER: M (Marine)
AB: The North Atlantic was the site for the 1989 JGOFS Pilot Study, an international study of ocean fluxes in relation to the carbon cycle. In this paper we present preliminary estimates of the grazing pressure by copepod assemblages at four stations: 60, 56, 52 and 47 degree N, along the JGOFS 20 degree W transect, during June-July. Three major size fractions of mesoplanktonic copepods were considered: small (200-500 mu m), medium (500-1000 mu m) and large (1000-2000 mu m). At each station, copepod composition and abundance were analysed and the gut fluorescence method was used to estimate ingestion rates. The results support the importance of the small size fraction relative to the other fractions, in terms of numerical abundance and their grazing impact. However, the total grazing pressure of copepods on phytoplankton was relatively minor during the period of sampling since the fraction of phytoplankton standing stock and primary production consumed by the copepods was on average < 1 and 2% respectively.
AN: 2500742
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TI: Organic C, N, and stable isotopic composition of particulate matter collected on glass-fiber and aluminum oxide filters.
AU: Altabet,-M.A.
AF: Woods Hole Oceanogr. Inst., Woods Hole, MA 02543, USA
SO: LIMNOL.-OCEANOGR. 1990. vol. 35, no. 4, pp. 902-909
LA: English
ER: M (Marine)
AB: There is recent evidence that commonly used glass-fiber filters do not quantitatively sample suspended particles in the open ocean. To test for potential artifacts, I compared the quantity and composition of particles retained on glass-fiber (Whatman GF/F, QM-A, and GF/D) and aluminum oxide filters (Anotec Anopore, 0.2- mu m pore size). At a site off Bermuda, most of the particles passed GF/D and QM-A filters. At both this site and the site of the JGOFS North Atlantic bloom experiment, the majority was retained on GF/F filters but a significant fraction passed through to be retained by Anopore filters ( similar to 30% of total). This fraction increased at and below the base of the euphotic zone. For the North Atlantic experiment, particles passing GF/F filters also accounted for up to 60% of the NH sub(4) super(+) and 80% of the NO sub(3) super(-) uptake into particle uptake. Uptake integrated over the upper 60 m, however, was not significantly underestimated by the GF/F filters.
AN: 2463479
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TI: France-JGOFS, ECOMARGE. Particle fluxes and ecosystem response on a continental margin: The Mediterranean experiment.
AU: Monaco,-A.; Biscaye,-P.E.; Pocklington,-R.-(eds.)
AF: Lab. Sedimentol. et Geochim. Mar., Univ. Perpignan, Ave. Villeneuve, 66025 Perpignan, France
SO: CONT.-SHELF-RES. 1990. vol. 10, no. 9-11, pp. 807-1155
LA: English
ER: M (Marine)
AB: This special issue summarizes several years of effort within the ECOMARGE programme (France-JGOFS, PFO) and is the first French multidisciplinary result within the field of particle flux studies.
AN: 2438343