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Physical (hydrography), chemical (CTD), and biological (water quality) processes of the Texas-Louisiana continental shelf, 2018 (NCEI Accession 0219157)

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Two sets of CTD data were taken during the 2018 Shelfwide Hypoxia cruise off the Louisiana continental shelf. Hydrographic data were obtained with the LUMCON SeaBird 911+ CTD system and a YSI 6820. Nutrient, pigment, suspended sediment, surface salinity, Secchi depth, Winkler results, and station information data were also acquired.
  • Cite as: Rabalais, Nancy (2020). Physical (hydrography), chemical (CTD), and biological (water quality) processes of the Texas-Louisiana continental shelf, 2018 (NCEI Accession 0219157). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://www.ncei.noaa.gov/archive/accession/0219157. Accessed [date].
gov.noaa.nodc:0219157
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Distributor NOAA National Centers for Environmental Information
+1-301-713-3277
NCEI.Info@noaa.gov
Dataset Point of Contact NOAA National Centers for Environmental Information
ncei.info@noaa.gov
Time Period 2018-07-23 to 2018-07-28
Spatial Bounding Box Coordinates
West: -93.4165
East: -89.4245
South: 28.499
North: 29.727
Spatial Coverage Map
General Documentation
Publication Dates
  • publication: 2020-08-27
Data Presentation Form Digital table - digital representation of facts or figures systematically displayed, especially in columns
Dataset Progress Status Complete - production of the data has been completed
Historical archive - data has been stored in an offline storage facility
Data Update Frequency As needed
Supplemental Information
Submission Package ID: AWW41G
Purpose The physical, biological and chemical data collected are part of a long-term coastal Louisiana dataset. The goal is to understand physical and biological processes that contribute to the causes of hypoxia and use the data to support environmental models for use by resource managers. The size of the hypoxic area is part of the baseline data considered by the Mississippi River/Gulf of Mexico Nutrient/Hypoxia Task Force.
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  • accessLevel: Public
  • Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. NOAA and NCEI cannot assume liability for any damages caused by any errors or omissions in these data. If appropriate, NCEI can only certify that the data it distributes are an authentic copy of the records that were accepted for inclusion in the NCEI archives.
Dataset Citation
  • Cite as: Rabalais, Nancy (2020). Physical (hydrography), chemical (CTD), and biological (water quality) processes of the Texas-Louisiana continental shelf, 2018 (NCEI Accession 0219157). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://www.ncei.noaa.gov/archive/accession/0219157. Accessed [date].
Cited Authors
Principal Investigators
Contributors
Resource Providers
Publishers
Acknowledgments
  • Related Funding Agency: NOAA National Ocean Service
Theme keywords NODC DATA TYPES THESAURUS NODC OBSERVATION TYPES THESAURUS WMO_CategoryCode
  • oceanography
Global Change Master Directory (GCMD) Science Keywords Provider Datatype Keywords
  • Inorganic suspended particulate matter
  • Mean Fo/Fa
  • Surface Photosynthetic Active Radiation (PAR)
  • Time
  • Total Suspended Sediments
  • organic suspended particulate material
  • pH mV
Data Center keywords NODC COLLECTING INSTITUTION NAMES THESAURUS NODC SUBMITTING INSTITUTION NAMES THESAURUS
Platform keywords NODC PLATFORM NAMES THESAURUS Global Change Master Directory (GCMD) Platform Keywords ICES/SeaDataNet Ship Codes
Instrument keywords NODC INSTRUMENT TYPES THESAURUS Global Change Master Directory (GCMD) Instrument Keywords Provider Instrument Keywords
  • Biospherical Instruments QSP-2300 (in water PAR)
  • Biospherical Instruments QSP-2300 and QSR2200
  • Biospherical Instruments Surface PAR QSR2200
  • Chelsea Instruments Aquatraka III fluorometer
  • Dual pumped SBE 3 temperature sensor
  • Dual pumped SBE 4 conductivity sensor
  • Furuno-SC50
  • GF/F Filter
  • Hanna HI2003-01
  • Knudsen Chirp Model 3260 (100kHz/12kHz)
  • Lachat QuikChem
  • Mettler Toledo DL28 Titrator
  • SBE 27 pH/O.R.P (Redox) sensor
  • SBE CTD
  • SBE CTD and SBE 43 dissolved oxygen sensor
  • SBE-9+, Paroscientific Digiquartz(r) pressure sensor
  • Scientific Computer System (SCS)
  • Sea-Bird SBE 43 dissolved oxygen sensor
  • Seabird model SBE-21 Thermosalinograph
  • Sonar Altimeter, Teledyne Benthos PSA-916
  • Turner digital 10-AU
  • WETLabs C-Star 25 cm path length transmissometer
Place keywords NODC SEA AREA NAMES THESAURUS Global Change Master Directory (GCMD) Location Keywords
Project keywords NODC PROJECT NAMES THESAURUS
Keywords NCEI ACCESSION NUMBER
Use Constraints
  • Cite as: Rabalais, Nancy (2020). Physical (hydrography), chemical (CTD), and biological (water quality) processes of the Texas-Louisiana continental shelf, 2018 (NCEI Accession 0219157). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://www.ncei.noaa.gov/archive/accession/0219157. Accessed [date].
Access Constraints
  • Use liability: NOAA and NCEI cannot provide any warranty as to the accuracy, reliability, or completeness of furnished data. Users assume responsibility to determine the usability of these data. The user is responsible for the results of any application of this data for other than its intended purpose.
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Lineage information for: dataset
Processing Steps
  • 2020-08-27T14:41:51Z - NCEI Accession 0219157 v1.1 was published.
Output Datasets
Lineage information for: dataset
Processing Steps
  • Parameter or Variable: LATITUDE (measured); Units: decimal degrees; Observation Category: in situ; Sampling Instrument: Furuno-SC50; Sampling and Analyzing Method: Shelfwide cruise station positions were logged from RV Pelican's differential GPS at the beginning of sampling operations. Stations were occupied along 13 generally North-South transects from the Mississippi River delta across the Louisiana and Texas coastal shelves. Station depths ranged from 5 to 39 meters. The objective was to delimit and describe the area of midsummer bottom dissolved oxygen less than 2 (mg/L). Northern end stations of transects were chosen based on the survey vessel's minimum depth limits for each longitude. The northern extent of hypoxia was not reached on transects B, C, D’, D. Hypoxic oxygen levels were found in transects A’, A, B, C, D’, D, E, F, and I.; Data Quality Method: GPS manufacturer's accuracy claim is 1-5 meters 95% of the time. If wind, currents and tidal forces moved the ship from the beginning way point more than 0.5 nmi, the Pelican was re-positioned..
  • Parameter or Variable: LONGITUDE (measured); Units: decimal degrees; Observation Category: in situ; Sampling Instrument: Furuno-SC50; Sampling and Analyzing Method: Shelfwide cruise station positions were logged from RV Pelican's differential GPS at the beginning of sampling operations. Stations were occupied along 13 generally North-South transects from the Mississippi River delta across the Louisiana and Texas coastal shelves. Station depths ranged from 5 to 39 meters. The objective was to delimit and describe the area of midsummer bottom dissolved oxygen less than 2 (mg/L). Northern end stations of transects were chosen based on the survey vessel's minimum depth limits for each longitude. The northern extent of hypoxia was not reached on transects B, C, D’, D. Hypoxic oxygen levels were found in transects A’, A, B, C, D’, D, E, F, and I.; Data Quality Method: GPS manufacturer's accuracy claim is 1-5 meters 95% of the time. If wind, currents and tidal forces moved the ship from the beginning way point more than 0.5 nmi, the Pelican was re-positioned..
  • Parameter or Variable: DISSOLVED OXYGEN (measured); Units: mg/L; Observation Category: in situ; Sampling Instrument: YSI - handheld multi-parameter instrument; Sampling and Analyzing Method: The YSI CTD was attached by chain to a lead weight. The weight was lowered to the bottom by hydrowire. With the weight on the bottom, the sonde was positioned approximately 0.5 meters above the bottom. When the oxygen sensor stabilized, a data record of all the sensor values was stored electronically. During the Shelfwide cruise, the sonde was raised in approximately 0.5-meter increments, after D.O. sensor stabilization on the bottom; data records were stored. After storing data for the few meters closest to the bottom, the sonde was raised to two to three meters from the surface and a data record was saved. The sonde was raised and records stored in approximately 0.5-meter increments until finally a record was stored with the sonde submerged but as close as possible to the surface.; Data Quality Method: The YSI 6820 Oxygen sensor was serviced and calibrated before deployment and maintained in accordance with YSI (http://www.ysi.com/) recommended procedure. The Sonde and Logger are returned to the factory at least annually for inspection and service. Small adjustments based on correlations with Shipboard Winkler Titrations and YSI values were made to YSI oxygen data for the Shelfwide cruise. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of range of instrument..
  • Parameter or Variable: CONDUCTIVITY (measured); Units: mS/cm; Observation Category: in situ; Sampling Instrument: YSI - handheld multi-parameter instrument; Sampling and Analyzing Method: The YSI CTD was attached by chain to a lead weight. The weight was lowered to the bottom by hydrowire. With the weight on the bottom, the sonde was positioned approximately 0.5 meters above the bottom. When the oxygen sensor stabilized, a data record of all the sensor values was stored electronically. During the Shelfwide cruise, the sonde was raised in approximately 0.5-meter increments, after D.O. sensor stabilization on the bottom; data records were stored. After storing data for the few meters closest to the bottom, the sonde was raised to two to three meters from the surface and a data record was saved. The sonde was raised and records stored in approximately 0.5-meter increments until finally a record was stored with the sonde submerged but as close as possible to the surface.; Data Quality Method: The YSI 6820 Conductivity sensor was serviced and calibrated before deployment and maintained in accordance with YSI (http://www.ysi.com/) recommended procedure. The Sonde and Logger are returned to the factory at least annually for inspection and service. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of range of instrument..
  • Parameter or Variable: TEMPERATURE [WATER TEMPERATURE] (measured); Units: degrees Celsius; Observation Category: in situ; Sampling Instrument: YSI - handheld multi-parameter instrument; Sampling and Analyzing Method: The YSI CTD was attached by chain to a lead weight. The weight was lowered to the bottom by hydrowire. With the weight on the bottom, the sonde was positioned approximately 0.5 meters above the bottom. When the oxygen sensor stabilized, a data record of all the sensor values was stored electronically. During the Shelfwide cruise, the sonde was raised in approximately 0.5-meter increments, after D.O. sensor stabilization on the bottom; data records were stored. After storing data for the few meters closest to the bottom, the sonde was raised to two to three meters from the surface and a data record was saved. The sonde was raised and records stored in approximately 0.5-meter increments until finally a record was stored with the sonde submerged but as close as possible to the surface.; Data Quality Method: The YSI 6820 temperature sensor was serviced and calibrated before deployment and maintained in accordance with YSI (http://www.ysi.com/) recommended procedure. The Sonde and Logger are returned to the factory at least annually for inspection and service. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of range of instrument..
  • Parameter or Variable: SALINITY (calculated); Units: psu; Observation Category: in situ; Sampling Instrument: YSI - handheld multi-parameter instrument; Sampling and Analyzing Method: The YSI CTD was attached by chain to a lead weight. The weight was lowered to the bottom by hydrowire. With the weight on the bottom, the sonde was positioned approximately 0.5 meters above the bottom. When the oxygen sensor stabilized, a data record of all the sensor values was stored electronically. During the Shelfwide cruise, the sonde was raised in approximately 0.5-meter increments, after D.O. sensor stabilization on the bottom; data records were stored. After storing data for the few meters closest to the bottom, the sonde was raised to two to three meters from the surface and a data record was saved. The sonde was raised and records stored in approximately 0.5-meter increments until finally a record was stored with the sonde submerged but as close as possible to the surface.; Data Quality Method: The YSI 6820 conductivity sensor was serviced and calibrated before deployment and maintained in accordance with YSI (http://www.ysi.com/) recommended procedure. The Sonde and Logger are returned to the factory at least annually for inspection and service. Small adjustments based on correlations with Hanna HI2003-01 Salinometer and YSI values were made to YSI salinity data for the Shelfwide cruise. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of range of instrument..
  • Parameter or Variable: OXYGEN - PERCENT SATURATION (calculated); Units: %; Observation Category: in situ; Sampling Instrument: YSI - handheld multi-parameter instrument; Sampling and Analyzing Method: The YSI CTD was attached by chain to a lead weight. The weight was lowered to the bottom by hydrowire. With the weight on the bottom, the sonde was positioned approximately 0.5 meters above the bottom. When the oxygen sensor stabilized, a data record of all the sensor values was stored electronically. During the Shelfwide cruise, the sonde was raised in approximately 0.5-meter increments, after D.O. sensor stabilization on the bottom; data records were stored. After storing data for the few meters closest to the bottom, the sonde was raised to two to three meters from the surface and a data record was saved. The sonde was raised and records stored in approximately 0.5-meter increments until finally a record was stored with the sonde submerged but as close as possible to the surface.; Data Quality Method: The YSI 6820 Conductivity, Oxygen, and Temperature sensors were serviced and calibrated before deployment and maintained in accordance with YSI (http://www.ysi.com/) recommended procedure. The Sonde and Logger are returned to the factory at least annually for inspection and service. Small adjustments were made to the oxygen percent saturation data for the Shelfwide cruise as a result of the corrections to the oxygen and salinity data via regressions with Winkler and Hanna HI2003-01 Salinometer data, respectively. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of range of instrument..
  • Parameter or Variable: INSTRUMENT - DEPTH (measured); Units: meter; Observation Category: in situ; Sampling Instrument: YSI - handheld multi-parameter instrument; Sampling and Analyzing Method: The YSI CTD was attached by chain to a lead weight. The weight was lowered to the bottom by hydrowire. With the weight on the bottom, the sonde was positioned approximately 0.5 meters above the bottom. When the oxygen sensor stabilized, a data record of all the sensor values was stored electronically. During the Shelfwide cruise, the sonde was raised in approximately 0.5-meter increments, after D.O. sensor stabilization on the bottom; data records were stored. After storing data for the few meters closest to the bottom, the sonde was raised to two to three meters from the surface and a data record was saved. The sonde was raised and records stored in approximately 0.5-meter increments until finally a record was stored with the sonde submerged but as close as possible to the surface.; Data Quality Method: The YSI 6820 pressure sensor was serviced and calibrated before deployment and maintained in accordance with YSI (http://www.ysi.com/) recommended procedure. The Sonde and Logger are returned to the factory at least annually for inspection and service. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of range of instrument. N.B. In an effort to measure the thin surface layer, there were occasions where the meter briefly breached the surface. These data reflect negative depth values. These data have been retained in the data set as they represent an important portion of the water column and represent reasonable values..
  • Parameter or Variable: AMMONIUM (NH4) (measured); Units: micromole/liter; Observation Category: laboratory analysis; Sampling Instrument: Lachat QuikChem; Sampling and Analyzing Method: Water for nutrient analyses was collected from the surface by twice-rinsed bucket at all stations; these samples are given depth a value of "0.” Bottom water samples for nutrient analyses were collected at all stations in a 5-l bottom tripping Niskin deployed on the YSI hydrowire. Generally, bottom depths of water samples correspond to the deepest depth recorded from the YSI. Care was taken that the collector's hands were clean and avoided touching the sample water. Gloves were worn when two replicate sample vials and caps were triple rinsed with sample before vial filling and closing. Samples were not filtered. The sample vials were frozen for later analysis in the laboratory using the Lachat Instrument's Method 31-107-06-1-B.; Data Quality Method: Nutrient analyses were conducted using a QuikChem 8000 FIA+ (http://www.lachatinstruments.com). Charlie Milan performed the analyses under the supervision of R. E. Turner, LSU. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of the range of the instrument..
  • Parameter or Variable: nitrate + nitrite content (concentration) (measured); Units: micromole/liter; Observation Category: laboratory analysis; Sampling Instrument: Lachat QuikChem; Sampling and Analyzing Method: Water for nutrient analyses was collected from the surface by twice-rinsed bucket at all stations; these samples are given depth a value of "0.” Bottom water samples for nutrient analyses were collected at all stations in a 5-l bottom tripping Niskin deployed on the YSI hydrowire. Generally, bottom depths of water samples correspond to the deepest depth recorded from the YSI. Care was taken that the collector's hands were clean and avoided touching the sample water. Gloves were worn when two replicate sample vials and caps were triple rinsed with sample before vial filling and closing. Samples were not filtered. The sample vials were frozen for later analysis in the laboratory using the Lachat Instrument's Method 31-107-04-1-C.; Data Quality Method: Nutrient analyses were conducted using a QuikChem 8000 FIA+ (http://www.lachatinstruments.com). Charlie Milan performed the analyses under the supervision of R. E. Turner, LSU. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of the range of the instrument..
  • Parameter or Variable: PHOSPHATE - INORGANIC [phosphate] (measured); Units: micromole/liter; Observation Category: laboratory analysis; Sampling Instrument: Lachat QuikChem; Sampling and Analyzing Method: Water for nutrient analyses was collected from the surface by twice-rinsed bucket at all stations; these samples are given depth a value of "0.” Bottom water samples for nutrient analyses were collected at all stations in a 5-l bottom tripping Niskin deployed on the YSI hydrowire. Generally, bottom depths of water samples correspond to the deepest depth recorded from the YSI. Care was taken that the collector's hands were clean and avoided touching the sample water. Gloves were worn when two replicate sample vials and caps were triple rinsed with sample before vial filling and closing. Samples were not filtered. The sample vials were frozen for later analysis in the laboratory using the Lachat Instrument's Method 31-115-01-1-H.; Data Quality Method: Nutrient analyses were conducted using a QuikChem 8000 FIA+ (http://www.lachatinstruments.com). Charlie Milan performed the analyses under the supervision of R. E. Turner, LSU. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of the range of the instrument..
  • Parameter or Variable: silicate (measured); Units: micromole/liter; Observation Category: laboratory analysis; Sampling Instrument: Lachat QuikChem; Sampling and Analyzing Method: Water for nutrient analyses was collected from the surface by twice-rinsed bucket at all stations; these samples are given depth a value of "0.” Bottom water samples for nutrient analyses were collected at all stations in a 5-l bottom tripping Niskin deployed on the YSI hydrowire. Generally, bottom depths of water samples correspond to the deepest depth recorded from the YSI. Care was taken that the collector's hands were clean and avoided touching the sample water. Gloves were worn when two replicate sample vials and caps were triple rinsed with sample before vial filling and closing. Samples were not filtered. The sample vials were frozen for later analysis in the laboratory using the Lachat Instrument's Method 31-114-27-1-C.; Data Quality Method: Nutrient analyses were conducted using a QuikChem 8000 FIA+ (http://www.lachatinstruments.com). Charlie Milan performed the analyses under the supervision of R. E. Turner, LSU. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of the range of the instrument..
  • Parameter or Variable: CHLOROPHYLL - EXTRACTED (measured); Units: microgram/liter; Observation Category: laboratory analysis; Sampling Instrument: Turner digital 10-AU; Sampling and Analyzing Method: Water for chlorophyll analyses was collected from the surface by twice-rinsed bucket at all stations; these samples are given depth a value of "0.” Bottom water samples for chlorophyll analyses were collected at all stations in a 5-l bottom tripping Niskin deployed on the YSI hydrowire. Generally, bottom depths of water samples correspond to the deepest depth recorded from the YSI. Water for chlorophyll analysis (10 - 100 ml) was filtered on board ship through GF/F (0.7 micron) filters, which were then fixed in 5 ml of DMSO/90% acetone (40/60) solution, allowed to extract for at least two hours in the dark, then measured pre- and post-acidification on a Turner Model 10 AU fluorometer.; Data Quality Method: The Turner Designs model 10 AU fluorometer was calibrated (7/17/14) for chlorophyll a against a chemical supply house chlorophyll a standard measured on a spectrophotometer. Each time the fluorometer was moved, it was tested with a Turner 10-AU solid standard. Solid standard measurements since the date of calibration, indicated no drift in the fluorescence detector. During cruises, the fluorometer was blanked and calibrated daily in accordance with Turner Designs recommended procedures. Pigment measurements were supervised by Nancy Rabalais and quality controlled by Nancy Rabalais. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with replicates and others in a continuous string, and outside of the range of the instrument..
  • Parameter or Variable: PHAEOPIGMENT CONCENTRATION (measured); Units: microgram/liter; Observation Category: laboratory analysis; Sampling Instrument: Turner digital 10-AU; Sampling and Analyzing Method: Water for chlorophyll analyses was collected from the surface by twice-rinsed bucket at all stations; these samples are given depth a value of "0.” Bottom water samples for chlorophyll analyses were collected at all stations in a 5-l bottom tripping Niskin deployed on the YSI hydrowire. Generally, bottom depths of water samples correspond to the deepest depth recorded from the YSI. Water for chlorophyll analysis (10 - 100 ml) was filtered on board ship through GF/F (0.7 micron) filters, which were then fixed in 5 ml of DMSO/90% acetone (40/60) solution, allowed to extract for at least two hours in the dark, then measured pre- and post-acidification on a Turner Model 10 AU fluorometer.; Data Quality Method: The Turner Designs model 10 AU fluorometer was calibrated (7/17/14) for chlorophyll a against a chemical supply house chlorophyll a standard measured on a spectrophotometer. Each time the fluorometer was moved, it was tested with a Turner 10-AU solid standard. Solid standard measurements since the date of calibration, indicated no drift in the fluorescence detector. During cruises, the fluorometer was blanked and calibrated daily in accordance with Turner Designs recommended procedures. Pigment measurements were supervised by Nancy Rabalais and quality controlled by Nancy Rabalais. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with replicates and others in a continuous string, and outside of the range of the instrument. If a calculated phaeopigment value is negative, that value is corrected to zero; related values are recalculated..
  • Parameter or Variable: Total PIGMENTS (calculated); Units: microgram/liter; Observation Category: laboratory analysis; Sampling Instrument: Turner digital 10-AU; Sampling and Analyzing Method: Water for chlorophyll analyses was collected from the surface by twice-rinsed bucket at all stations; these samples are given depth a value of "0.” Bottom water samples for chlorophyll analyses were collected at all stations in a 5-l bottom tripping Niskin deployed on the YSI hydrowire. Generally, bottom depths of water samples correspond to the deepest depth recorded from the YSI. Water for chlorophyll analysis (10 - 100 ml) was filtered on board ship through GF/F (0.7 micron) filters, which were then fixed in 5 ml of DMSO/90% acetone (40/60) solution, allowed to extract for at least two hours in the dark, then measured pre- and post-acidification on a Turner Model 10 AU fluorometer.; Data Quality Method: The Turner Designs model 10 AU fluorometer was calibrated (7/17/14) for chlorophyll a against a chemical supply house chlorophyll a standard measured on a spectrophotometer. Each time the fluorometer was moved, it was tested with a Turner 10-AU solid standard. Solid standard measurements since the date of calibration, indicated no drift in the fluorescence detector. During cruises, the fluorometer was blanked and calibrated daily in accordance with Turner Designs recommended procedures. Pigment measurements were supervised by Nancy Rabalais and quality controlled by Nancy Rabalais. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with replicates and others in a continuous string, and outside of the range of the instrument..
  • Parameter or Variable: Mean Fo/Fa (calculated); Units: unitless; Observation Category: laboratory analysis; Sampling Instrument: Turner digital 10-AU; Sampling and Analyzing Method: : Fo/Fa represents the ratio between the pre- and post-acidification (%HCl) measurements.; Data Quality Method: The Turner Designs model 10 AU fluorometer was calibrated (7/17/14) for chlorophyll a against a chemical supply house chlorophyll a standard measured on a spectrophotometer. Each time the fluorometer was moved, it was tested with a Turner 10-AU solid standard. Solid standard measurements since the date of calibration, indicated no drift in the fluorescence detector. During cruises, the fluorometer was blanked and calibrated daily in accordance with Turner Designs recommended procedures. Pigment measurements were supervised by Nancy Rabalais and quality controlled by Nancy Rabalais. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with replicates and others in a continuous string, and outside of the range of the instrument..
  • Parameter or Variable: SALINITY (measured); Units: psu; Observation Category: laboratory analysis; Sampling Instrument: Hanna HI2003-01; Sampling and Analyzing Method: Water for salinity analyses was collected from Mississippi River stations and stations on the C and F transects. Surface samples were collected from a twice-rinsed bucket and given depth a value of "0.” Bottom water samples for salinity analyses were collected in a 5-L bottom tripping Niskin deployed on the YSI hydrowire. Generally, bottom depths of water samples correspond to the deepest depth recorded from the YSI. Water was collected in an acid-washed, triple-rinsed 500ml Nalgene jar from a twice-rinsed bucket of surface water. The jar lid was secured tightly to minimize evaporation. Salinity samples were analyzed in the lab with a Hanna Instruments Salinometer (Hanna HI2003-01), using methods derived from Hanna protocols (https://hannainst.com).; Data Quality Method: Salinity samples were analyzed in the lab with a Hanna Instruments Salinometer, using methods derived from Hanna protocols (https://hannainst.com). Salinity analyses were conducted by Gina Woods under the supervision of Wendy Morrison. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of the range of the instrument..
  • Parameter or Variable: DISSOLVED OXYGEN (measured); Units: mg/L; Observation Category: laboratory analysis; Sampling Instrument: Mettler Toledo DL28 Titrator; Sampling and Analyzing Method: Water was collected from Niskin bottle samples using a 300ml glass BOD bottle. Care was taken so that air bubbles were not introduced into the water sample and titration reagents were added immediately to fix the oxygen. Stations and depths were selected as water samples for Winkler analysis based on homogeneity the oxygen profile around that depth, and the need for a distribution of oxygen values across the observed oxygen range.; Data Quality Method: Winkler samples were analyzed on board the RV Pelican with a Mettler Toledo DL28 Titrator (http://www.mt.com/).using dissolved oxygen determination methods outlined in A Practical Handbook of Seawater Analysis by Strickland and Parsons, 1977. Winkler analyses were conducted by Wendy Morrison and Nancy Rabalais. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with replicates and others in a continuous string, and outside of the range of the instrument..
  • Parameter or Variable: DEPTH - SENSOR (measured); Units: meter; Observation Category: in situ; Sampling Instrument: SBE-9+, Paroscientific Digiquartz(r) pressure sensor; Sampling and Analyzing Method: The SeaBird CTD number of scans to average in the deck unit was set to one. At the beginning of each hydrocast, the entire CTD/Rosette package was soaked while submerged 0.5m to 1.0m below the surface until pump flow and oxygen values observed via the Sea-Bird deck unit indicated the system was operating correctly. In order to minimize the effect of delays in oxygen sensor response time caused by temperature, sensor condition and plumbing configuration, the CTD package was lowered and raised as close to dead slow as possible. The sensor packages were located below the Niskin bottles and rosette. Sea-Bird CTD data were acquired using Seasoft and processed using SBE Data Processing-Win32 software. All scans were processed without averaging or interpolation with a bin size of one scan. In order to compensate for the delay in oxygen sensor response time and improve the alignment between oxygen sensor values and temperature and conductivity sensor values, the Seasoft module ALIGNCTD was used. Stations used for alignment were those where the structure of the oxygen profile contained dominant features. After alignment, the DERIVE function was used to calculate Depth (m), Salinity (psu), Density sigma-t (kg/m3), Oxygen concentration (mg/L), and Oxygen percent saturation (%). Final data were exported as ascii files. A MATLAB program was then used to select a water column profile made up of scans from the downcast of discrete 1-meter (or 0.1-m) measurements from the ascii files. The MATLAB program selected scans as follows: 1) Data from Seabird warm up period sitting on the surface were removed; 2) Upcast data were removed; 3) Data scans were selected at 1.0 meter increments through the water column; 3) When D.O. values changed significantly (> 1.0 mgO2/L) within 1-meter, scans at 0.1-m intervals were selected within that meter; 4) Minimum oxygen and maximum depth scans were selected.; Data Quality Method: The Paroscientific Digiquartz(r) pressure sensor was factory tested and calibrated at Sea-Bird (http://www.seabird.com/) recommended intervals and maintained and serviced by RV Pelican Electronic Technical support staff in accordance with Sea-Bird procedures. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of the range of the instrument..
  • Parameter or Variable: SONAR ALTIMETER (measured); Units: meter; Observation Category: in situ; Sampling Instrument: Sonar Altimeter, Teledyne Benthos PSA-916; Sampling and Analyzing Method: The SeaBird CTD number of scans to average in the deck unit was set to one. At the beginning of each hydrocast, the entire CTD/Rosette package was soaked while submerged 0.5m to 1.0m below the surface until pump flow and oxygen values observed via the Sea-Bird deck unit indicated the system was operating correctly. Sensor packages are located below the Niskin bottle rosette sampler. In order to minimize the effect of delays in oxygen sensor response time caused by temperature, sensor condition and plumbing configuration, the CTD package was lowered and raised as close to dead slow as possible. The sensor packages were located below the Niskin bottles and rosette. Sea-Bird CTD data were acquired using Seasoft and processed using SBE Data Processing-Win32 software. All scans were processed without averaging or interpolation with a bin size of one scan. In order to compensate for the delay in oxygen sensor response time and improve the alignment between oxygen sensor values and temperature and conductivity sensor values, the Seasoft module ALIGNCTD was used. Stations used for alignment were those where the structure of the oxygen profile contained dominant features. After alignment, the DERIVE function was used to calculate Depth (m), Salinity (psu), Density sigma-t (kg/m3), Oxygen concentration (mg/L), and Oxygen percent saturation (%). Final data were exported as ascii files. A MATLAB program was then used to select a water column profile made up of scans from the downcast of discrete 1-meter (or 0.1-m) measurements from the ascii files. The MATLAB program selected scans as follows: 1) Data from Seabird warm up period sitting on the surface were removed; 2) Upcast data were removed; 3) Data scans were selected at 1.0 meter increments through the water column; 3) When D.O. values changed significantly (> 1.0 mgO2/L) within 1-meter, scans at 0.1-m intervals were selected within that meter; 4) Minimum oxygen and maximum depth scans were selected.; Data Quality Method: The Teledyne Benthos Altimeter PSA-916 sonar altimeter was factory tested and calibrated at manufacturer recommended intervals and maintained and serviced by RV Pelican Electronic Technical support staff. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of the range of the instrument. N.B. near bottom high altimeter values (>6.0 m) were deleted throughout the dataset, because probes were likely within 1 meter of the bottom..
  • Parameter or Variable: PHOTOSYNTHETIC ACTIVE RADIATION (PAR) (measured); Units: microEinsteins/meter^2*sec; Observation Category: in situ; Sampling Instrument: Biospherical Instruments QSP-2300 (in water PAR); Sampling and Analyzing Method: The SeaBird CTD number of scans to average in the deck unit was set to one. At the beginning of each hydrocast, the entire CTD/Rosette package was soaked while submerged 0.5m to 1.0m below the surface until pump flow and oxygen values observed via the Sea-Bird deck unit indicated the system was operating correctly. Sensor packages are located below the Niskin bottle rosette sampler. In order to minimize the effect of delays in oxygen sensor response time caused by temperature, sensor condition and plumbing configuration, the CTD package was lowered and raised as close to dead slow as possible. The sensor packages were located below the Niskin bottles and rosette. Sea-Bird CTD data were acquired using Seasoft and processed using SBE Data Processing-Win32 software. All scans were processed without averaging or interpolation with a bin size of one scan. In order to compensate for the delay in oxygen sensor response time and improve the alignment between oxygen sensor values and temperature and conductivity sensor values, the Seasoft module ALIGNCTD was used. Stations used for alignment were those where the structure of the oxygen profile contained dominant features. After alignment, the DERIVE function was used to calculate Depth (m), Salinity (psu), Density sigma-t (kg/m3), Oxygen concentration (mg/L), and Oxygen percent saturation (%). Final data were exported as ascii files. A MATLAB program was then used to select a water column profile made up of scans from the downcast of discrete 1-meter (or 0.1-m) measurements from the ascii files. The MATLAB program selected scans as follows: 1) Data from Seabird warm up period sitting on the surface were removed; 2) Upcast data were removed; 3) Data scans were selected at 1.0 meter increments through the water column; 3) When D.O. values changed significantly (> 1.0 mgO2/L) within 1-meter, scans at 0.1-m intervals were selected within that meter; 4) Minimum oxygen and maximum depth scans were selected.; Data Quality Method: The Biospherical Instruments QSP-2300 in water PAR sensor was factory tested and calibrated at manufacturer recommended intervals and maintained and serviced by RV Pelican Electronic Technical support staff. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of the range of the instrument. N.B. Operations were conducted 24-hrs a day and as such, some irradiance values reflect nighttime values. In order to make this clear, irradiance values are provided as in-water and surface PAR data as well as the calculated % Irradiance calculated as the percentage of light from the surface observed at that depth in the water column (in-water PAR / surface PAR * 100)..
  • Parameter or Variable: LIGHT TRANSMISSION (measured); Units: percent; Observation Category: in situ; Sampling Instrument: WETLabs C-Star 25 cm path length transmissometer; Sampling and Analyzing Method: The SeaBird CTD number of scans to average in the deck unit was set to one. At the beginning of each hydrocast, the entire CTD/Rosette package was soaked while submerged 0.5m to 1.0m below the surface until pump flow and oxygen values observed via the Sea-Bird deck unit indicated the system was operating correctly. Sensor packages are located below the Niskin bottle rosette sampler. In order to minimize the effect of delays in oxygen sensor response time caused by temperature, sensor condition and plumbing configuration, the CTD package was lowered and raised as close to dead slow as possible. The sensor packages were located below the Niskin bottles and rosette. Sea-Bird CTD data were acquired using Seasoft and processed using SBE Data Processing-Win32 software. All scans were processed without averaging or interpolation with a bin size of one scan. In order to compensate for the delay in oxygen sensor response time and improve the alignment between oxygen sensor values and temperature and conductivity sensor values, the Seasoft module ALIGNCTD was used. Stations used for alignment were those where the structure of the oxygen profile contained dominant features. After alignment, the DERIVE function was used to calculate Depth (m), Salinity (psu), Density sigma-t (kg/m3), Oxygen concentration (mg/L), and Oxygen percent saturation (%). Final data were exported as ascii files. A MATLAB program was then used to select a water column profile made up of scans from the downcast of discrete 1-meter (or 0.1-m) measurements from the ascii files. The MATLAB program selected scans as follows: 1) Data from Seabird warm up period sitting on the surface were removed; 2) Upcast data were removed; 3) Data scans were selected at 1.0 meter increments through the water column; 3) When D.O. values changed significantly (> 1.0 mgO2/L) within 1-meter, scans at 0.1-m intervals were selected within that meter; 4) Minimum oxygen and maximum depth scans were selected.; Data Quality Method: The WETLabs C-Star 25 cm path length transmissometer was factory tested and calibrated at manufacturer recommended intervals and maintained and serviced by RV Pelican Electronic Technical support staff. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of the range of the instrument..
  • Parameter or Variable: FLUORESCENCE (measured); Units: microgram/liter; Observation Category: in situ; Sampling Instrument: Chelsea Instruments Aquatraka III fluorometer; Sampling and Analyzing Method: The SeaBird CTD number of scans to average in the deck unit was set to one. At the beginning of each hydrocast, the entire CTD/Rosette package was soaked while submerged 0.5m to 1.0m below the surface until pump flow and oxygen values observed via the Sea-Bird deck unit indicated the system was operating correctly. Sensor packages are located below the Niskin bottle rosette sampler. In order to minimize the effect of delays in oxygen sensor response time caused by temperature, sensor condition and plumbing configuration, the CTD package was lowered and raised as close to dead slow as possible. The sensor packages were located below the Niskin bottles and rosette. Sea-Bird CTD data were acquired using Seasoft and processed using SBE Data Processing-Win32 software. All scans were processed without averaging or interpolation with a bin size of one scan. In order to compensate for the delay in oxygen sensor response time and improve the alignment between oxygen sensor values and temperature and conductivity sensor values, the Seasoft module ALIGNCTD was used. Stations used for alignment were those where the structure of the oxygen profile contained dominant features. After alignment, the DERIVE function was used to calculate Depth (m), Salinity (psu), Density sigma-t (kg/m3), Oxygen concentration (mg/L), and Oxygen percent saturation (%). Final data were exported as ascii files. A MATLAB program was then used to select a water column profile made up of scans from the downcast of discrete 1-meter (or 0.1-m) measurements from the ascii files. The MATLAB program selected scans as follows: 1) Data from Seabird warm up period sitting on the surface were removed; 2) Upcast data were removed; 3) Data scans were selected at 1.0 meter increments through the water column; 3) When D.O. values changed significantly (> 1.0 mgO2/L) within 1-meter, scans at 0.1-m intervals were selected within that meter; 4) Minimum oxygen and maximum depth scans were selected.; Data Quality Method: The Chelsea Instruments Aquatraka III fluorometer was factory tested and calibrated at manufacturer recommended intervals and maintained and serviced by RV Pelican Electronic Technical support staff. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of the range of the instrument..
  • Parameter or Variable: TEMPERATURE - WATER [WATER TEMPERATURE] (measured); Units: degrees Celsius; Observation Category: in situ; Sampling Instrument: Dual pumped SBE 3 temperature sensor; Sampling and Analyzing Method: The SeaBird CTD number of scans to average in the deck unit was set to one. At the beginning of each hydrocast, the entire CTD/Rosette package was soaked while submerged 0.5m to 1.0m below the surface until pump flow and oxygen values observed via the Sea-Bird deck unit indicated the system was operating correctly. Sensor packages are located below the Niskin bottle rosette sampler. In order to minimize the effect of delays in oxygen sensor response time caused by temperature, sensor condition and plumbing configuration, the CTD package was lowered and raised as close to dead slow as possible. The sensor packages were located below the Niskin bottles and rosette. Sea-Bird CTD data were acquired using Seasoft and processed using SBE Data Processing-Win32 software. All scans were processed without averaging or interpolation with a bin size of one scan. In order to compensate for the delay in oxygen sensor response time and improve the alignment between oxygen sensor values and temperature and conductivity sensor values, the Seasoft module ALIGNCTD was used. Stations used for alignment were those where the structure of the oxygen profile contained dominant features. After alignment, the DERIVE function was used to calculate Depth (m), Salinity (psu), Density sigma-t (kg/m3), Oxygen concentration (mg/L), and Oxygen percent saturation (%). Final data were exported as ascii files. A MATLAB program was then used to select a water column profile made up of scans from the downcast of discrete 1-meter (or 0.1-m) measurements from the ascii files. The MATLAB program selected scans as follows: 1) Data from Seabird warm up period sitting on the surface were removed; 2) Upcast data were removed; 3) Data scans were selected at 1.0 meter increments through the water column; 3) When D.O. values changed significantly (> 1.0 mgO2/L) within 1-meter, scans at 0.1-m intervals were selected within that meter; 4) Minimum oxygen and maximum depth scans were selected.; Data Quality Method: The Dual pumped SBE 3 temperature sensor was factory tested and calibrated at manufacturer recommended intervals and maintained and serviced by RV Pelican Electronic Technical support staff. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of the range of the instrument..
  • Parameter or Variable: CONDUCTIVITY (measured); Units: siemens/m; Observation Category: in situ; Sampling Instrument: Dual pumped SBE 4 conductivity sensor; Sampling and Analyzing Method: The SeaBird CTD number of scans to average in the deck unit was set to one. At the beginning of each hydrocast, the entire CTD/Rosette package was soaked while submerged 0.5m to 1.0m below the surface until pump flow and oxygen values observed via the Sea-Bird deck unit indicated the system was operating correctly. Sensor packages are located below the Niskin bottle rosette sampler. In order to minimize the effect of delays in oxygen sensor response time caused by temperature, sensor condition and plumbing configuration, the CTD package was lowered and raised as close to dead slow as possible. The sensor packages were located below the Niskin bottles and rosette. Sea-Bird CTD data were acquired using Seasoft and processed using SBE Data Processing-Win32 software. All scans were processed without averaging or interpolation with a bin size of one scan. In order to compensate for the delay in oxygen sensor response time and improve the alignment between oxygen sensor values and temperature and conductivity sensor values, the Seasoft module ALIGNCTD was used. Stations used for alignment were those where the structure of the oxygen profile contained dominant features. After alignment, the DERIVE function was used to calculate Depth (m), Salinity (psu), Density sigma-t (kg/m3), Oxygen concentration (mg/L), and Oxygen percent saturation (%). Final data were exported as ascii files. A MATLAB program was then used to select a water column profile made up of scans from the downcast of discrete 1-meter (or 0.1-m) measurements from the ascii files. The MATLAB program selected scans as follows: 1) Data from Seabird warm up period sitting on the surface were removed; 2) Upcast data were removed; 3) Data scans were selected at 1.0 meter increments through the water column; 3) When D.O. values changed significantly (> 1.0 mgO2/L) within 1-meter, scans at 0.1-m intervals were selected within that meter; 4) Minimum oxygen and maximum depth scans were selected.; Data Quality Method: The Dual pumped SBE 4 conductivity sensor was factory tested and calibrated at manufacturer recommended intervals and maintained and serviced by RV Pelican Electronic Technical support staff. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of the range of the instrument..
  • Parameter or Variable: SALINITY (calculated); Units: psu; Observation Category: in situ; Sampling Instrument: Dual pumped SBE 4 conductivity sensor; Sampling and Analyzing Method: The SeaBird CTD number of scans to average in the deck unit was set to one. At the beginning of each hydrocast, the entire CTD/Rosette package was soaked while submerged 0.5m to 1.0m below the surface until pump flow and oxygen values observed via the Sea-Bird deck unit indicated the system was operating correctly. Sensor packages are located below the Niskin bottle rosette sampler. In order to minimize the effect of delays in oxygen sensor response time caused by temperature, sensor condition and plumbing configuration, the CTD package was lowered and raised as close to dead slow as possible. The sensor packages were located below the Niskin bottles and rosette. Sea-Bird CTD data were acquired using Seasoft and processed using SBE Data Processing-Win32 software. All scans were processed without averaging or interpolation with a bin size of one scan. In order to compensate for the delay in oxygen sensor response time and improve the alignment between oxygen sensor values and temperature and conductivity sensor values, the Seasoft module ALIGNCTD was used. Stations used for alignment were those where the structure of the oxygen profile contained dominant features. After alignment, the DERIVE function was used to calculate Depth (m), Salinity (psu), Density sigma-t (kg/m3), Oxygen concentration (mg/L), and Oxygen percent saturation (%). Final data were exported as ascii files. A MATLAB program was then used to select a water column profile made up of scans from the downcast of discrete 1-meter (or 0.1-m) measurements from the ascii files. The MATLAB program selected scans as follows: 1) Data from Seabird warm up period sitting on the surface were removed; 2) Upcast data were removed; 3) Data scans were selected at 1.0 meter increments through the water column; 3) When D.O. values changed significantly (> 1.0 mgO2/L) within 1-meter, scans at 0.1-m intervals were selected within that meter; 4) Minimum oxygen and maximum depth scans were selected.; Data Quality Method: The Dual pumped SBE 4 conductivity sensor was factory tested and calibrated at manufacturer recommended intervals and maintained and serviced by RV Pelican Electronic Technical support staff. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of the range of the instrument. Small adjustments were made to the Shelfwide cruise salinity data, based on correlations with Hanna Salinometer and SeaBird values..
  • Parameter or Variable: WATER DENSITY (calculated); Units: kilogram/meter^3; Observation Category: in situ; Sampling Instrument: SBE CTD; Sampling and Analyzing Method: The SeaBird CTD number of scans to average in the deck unit was set to one. At the beginning of each hydrocast, the entire CTD/Rosette package was soaked while submerged 0.5m to 1.0m below the surface until pump flow and oxygen values observed via the Sea-Bird deck unit indicated the system was operating correctly. Sensor packages are located below the Niskin bottle rosette sampler. In order to minimize the effect of delays in oxygen sensor response time caused by temperature, sensor condition and plumbing configuration, the CTD package was lowered and raised as close to dead slow as possible. The sensor packages were located below the Niskin bottles and rosette. Sea-Bird CTD data were acquired using Seasoft and processed using SBE Data Processing-Win32 software. All scans were processed without averaging or interpolation with a bin size of one scan. In order to compensate for the delay in oxygen sensor response time and improve the alignment between oxygen sensor values and temperature and conductivity sensor values, the Seasoft module ALIGNCTD was used. Stations used for alignment were those where the structure of the oxygen profile contained dominant features. After alignment, the DERIVE function was used to calculate Depth (m), Salinity (psu), Density sigma-t (kg/m3), Oxygen concentration (mg/L), and Oxygen percent saturation (%). Final data were exported as ascii files. A MATLAB program was then used to select a water column profile made up of scans from the downcast of discrete 1-meter (or 0.1-m) measurements from the ascii files. The MATLAB program selected scans as follows: 1) Data from Seabird warm up period sitting on the surface were removed; 2) Upcast data were removed; 3) Data scans were selected at 1.0 meter increments through the water column; 3) When D.O. values changed significantly (> 1.0 mgO2/L) within 1-meter, scans at 0.1-m intervals were selected within that meter; 4) Minimum oxygen and maximum depth scans were selected.; Data Quality Method: All sensors on the shipboard CTD were factory tested and calibrated at manufacturer recommended intervals and maintained and serviced by RV Pelican Electronic Technical support staff. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of the range of the instrument. Density values were calculated using corrected salinity data as well as measured temperature and pressure data..
  • Parameter or Variable: DISSOLVED OXYGEN (measured); Units: mg/L; Observation Category: in situ; Sampling Instrument: Sea-Bird SBE 43 dissolved oxygen sensor; Sampling and Analyzing Method: The SeaBird CTD number of scans to average in the deck unit was set to one. At the beginning of each hydrocast, the entire CTD/Rosette package was soaked while submerged 0.5m to 1.0m below the surface until pump flow and oxygen values observed via the Sea-Bird deck unit indicated the system was operating correctly. Sensor packages are located below the Niskin bottle rosette sampler. In order to minimize the effect of delays in oxygen sensor response time caused by temperature, sensor condition and plumbing configuration, the CTD package was lowered and raised as close to dead slow as possible. The sensor packages were located below the Niskin bottles and rosette. Sea-Bird CTD data were acquired using Seasoft and processed using SBE Data Processing-Win32 software. All scans were processed without averaging or interpolation with a bin size of one scan. In order to compensate for the delay in oxygen sensor response time and improve the alignment between oxygen sensor values and temperature and conductivity sensor values, the Seasoft module ALIGNCTD was used. Stations used for alignment were those where the structure of the oxygen profile contained dominant features. After alignment, the DERIVE function was used to calculate Depth (m), Salinity (psu), Density sigma-t (kg/m3), Oxygen concentration (mg/L), and Oxygen percent saturation (%). Final data were exported as ascii files. A MATLAB program was then used to select a water column profile made up of scans from the downcast of discrete 1-meter (or 0.1-m) measurements from the ascii files. The MATLAB program selected scans as follows: 1) Data from Seabird warm up period sitting on the surface were removed; 2) Upcast data were removed; 3) Data scans were selected at 1.0 meter increments through the water column; 3) When D.O. values changed significantly (> 1.0 mgO2/L) within 1-meter, scans at 0.1-m intervals were selected within that meter; 4) Minimum oxygen and maximum depth scans were selected.; Data Quality Method: Sea-Bird SBE 43 dissolved oxygen sensor was factory tested and calibrated at manufacturer recommended intervals and maintained and serviced by RV Pelican Electronic Technical support staff. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of the range of the instrument. At the beginning of the Shelfwide cruise, oxygen sensors were calibrated using the procedures described in SeaBird APPLICATION NOTE NO. 13-1, Rev. D. After the cruise, small adjustments based on correlations with Shipboard Winkler Titrations conducted at various stations during the cruise and corrections were made to the SeaBird oxygen data..
  • Parameter or Variable: OXYGEN - PERCENT SATURATION (calculated); Units: percent; Observation Category: in situ; Sampling Instrument: SBE CTD and SBE 43 dissolved oxygen sensor; Sampling and Analyzing Method: The SeaBird CTD number of scans to average in the deck unit was set to one. At the beginning of each hydrocast, the entire CTD/Rosette package was soaked while submerged 0.5m to 1.0m below the surface until pump flow and oxygen values observed via the Sea-Bird deck unit indicated the system was operating correctly. Sensor packages are located below the Niskin bottle rosette sampler. In order to minimize the effect of delays in oxygen sensor response time caused by temperature, sensor condition and plumbing configuration, the CTD package was lowered and raised as close to dead slow as possible. The sensor packages were located below the Niskin bottles and rosette. Sea-Bird CTD data were acquired using Seasoft and processed using SBE Data Processing-Win32 software. All scans were processed without averaging or interpolation with a bin size of one scan. In order to compensate for the delay in oxygen sensor response time and improve the alignment between oxygen sensor values and temperature and conductivity sensor values, the Seasoft module ALIGNCTD was used. Stations used for alignment were those where the structure of the oxygen profile contained dominant features. After alignment, the DERIVE function was used to calculate Depth (m), Salinity (psu), Density sigma-t (kg/m3), Oxygen concentration (mg/L), and Oxygen percent saturation (%). Final data were exported as ascii files. A MATLAB program was then used to select a water column profile made up of scans from the downcast of discrete 1-meter (or 0.1-m) measurements from the ascii files. The MATLAB program selected scans as follows: 1) Data from Seabird warm up period sitting on the surface were removed; 2) Upcast data were removed; 3) Data scans were selected at 1.0 meter increments through the water column; 3) When D.O. values changed significantly (> 1.0 mgO2/L) within 1-meter, scans at 0.1-m intervals were selected within that meter; 4) Minimum oxygen and maximum depth scans were selected.; Data Quality Method: All sensors on the shipboard CTD were factory tested and calibrated at manufacturer recommended intervals and maintained and serviced by RV Pelican Electronic Technical support staff. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of the range of the instrument. Oxygen Percent Saturation values were calculated using corrected oxygen and salinity data as well as measured temperature data..
  • Parameter or Variable: Time (measured); Units: Zulu; Observation Category: in situ; Sampling Instrument: Scientific Computer System (SCS); Data Quality Method: The RV Pelican's Scientific Computer System (SCS) program was written by NOAA and is maintained by the ship's electronic staff..
  • Parameter or Variable: DEPTH - BOTTOM (measured); Units: meter; Observation Category: in situ; Sampling Instrument: Knudsen Chirp Model 3260 (100kHz/12kHz); Sampling and Analyzing Method: Stations were occupied along 13 generally North-South transects from the Mississippi River delta across the Louisiana and Texas coastal shelves. Station depths ranged from 5 to 39 meters.; Data Quality Method: The RV Pelican's Knudsen Chirp Model 3260 echosounder is maintained by the ship's electronic staff..
  • Parameter or Variable: SALINITY - SURFACE WATER (measured); Units: psu; Observation Category: in situ; Sampling Instrument: Seabird model SBE-21 Thermosalinograph; Sampling and Analyzing Method: Surface salinity is measured from water collected in the ship's flow-through system.; Data Quality Method: The RV Pelican's Seabird model SBE-21 Thermosalinograph is maintained by the ship's electronic staff..
  • Parameter or Variable: SECCHI DEPTH (measured); Units: meter; Observation Category: in situ; Sampling Instrument: secchi disk; Sampling and Analyzing Method: Secchi disk depths were measured by hand using standard protocol. Secchi disk depths were only measured during daylight operations..
  • Parameter or Variable: CHLOROPHYLL - RELATIVE FLUORESCENCE (measured); Units: ug/L; Observation Category: in situ; Sampling Instrument: YSI - handheld multi-parameter instrument; Sampling and Analyzing Method: The YSI CTD was attached by chain to a lead weight. The weight was lowered to the bottom by hydrowire. With the weight on the bottom, the sonde was positioned approximately 0.5 meters above the bottom. When the oxygen sensor stabilized, a data record of all the sensor values was stored electronically. During the Shelfwide cruise, the sonde was raised in approximately 0.5-meter increments, after D.O. sensor stabilization on the bottom; data records were stored. After storing data for the few meters closest to the bottom, the sonde was raised to two to three meters from the surface and a data record was saved. The sonde was raised and records stored in approximately 0.5-meter increments until finally a record was stored with the sonde submerged but as close as possible to the surface.; Data Quality Method: Chlorophyll data are not included in the 2018 dataset as the data returned were not reliable..
  • Parameter or Variable: pH (measured); Units: unitless; Observation Category: in situ; Sampling Instrument: YSI - handheld multi-parameter instrument; Sampling and Analyzing Method: The YSI CTD was attached by chain to a lead weight. The weight was lowered to the bottom by hydrowire. With the weight on the bottom, the sonde was positioned approximately 0.5 meters above the bottom. When the oxygen sensor stabilized, a data record of all the sensor values was stored electronically. During the Shelfwide cruise, the sonde was raised in approximately 0.5-meter increments, after D.O. sensor stabilization on the bottom; data records were stored. After storing data for the few meters closest to the bottom, the sonde was raised to two to three meters from the surface and a data record was saved. The sonde was raised and records stored in approximately 0.5-meter increments until finally a record was stored with the sonde submerged but as close as possible to the surface.; Data Quality Method: pH data are not included in the 2018 dataset as the data returned were not reliable..
  • Parameter or Variable: Inorganic suspended particulate matter (measured); Units: mg/L; Observation Category: laboratory analysis; Sampling Instrument: GF/F Filter; Sampling and Analyzing Method: Water for suspended sediment analyses was collected from the surface by twice-rinsed bucket and given the depth value of "0". Water (approximately 50 to 1500 ml) collected for suspended sediment samples was filtered on board ship through (pre-combusted, pre-weighed) GF/F filters and rinsed with distilled water. The filters were placed in Petri dishes and frozen for later analysis. Suspended sediment filters were dried overnight at 60°C and weighed. The filters were then combusted at 400°C for 12 hours and weighed. The weights of the total suspended, organic and inorganic materials were derived.; Data Quality Method: Suspended sediment concentrations were supervised and quality controlled by Nancy Rabalais. Visual inspection was conducted on all data for values +/- 2 SD of mean and inconsistent with others in a continuous string..
  • Parameter or Variable: organic suspended particulate material (measured); Units: mg/L; Observation Category: laboratory analysis; Sampling Instrument: GF/F Filter; Sampling and Analyzing Method: Water for suspended sediment analyses was collected from the surface by twice-rinsed bucket and given the depth value of "0". Water (approximately 50 to 1500 ml) collected for suspended sediment samples was filtered on board ship through (pre-combusted, pre-weighed) GF/F filters and rinsed with distilled water. The filters were placed in Petri dishes and frozen for later analysis. Suspended sediment filters were dried overnight at 60°C and weighed. The filters were then combusted at 400°C for 12 hours and weighed. The weights of the total suspended, organic and inorganic materials were derived.; Data Quality Method: Suspended sediment concentrations were supervised and quality controlled by Nancy Rabalais. Visual inspection was conducted on all data for values +/- 2 SD of mean and inconsistent with others in a continuous string..
  • Parameter or Variable: Total Suspended Sediments (measured); Units: mg/L; Observation Category: laboratory analysis; Sampling Instrument: GF/F Filter; Sampling and Analyzing Method: Water for suspended sediment analyses was collected from the surface by twice-rinsed bucket and given the depth value of "0". Water (approximately 50 to 1500 ml) collected for suspended sediment samples was filtered on board ship through (pre-combusted, pre-weighed) GF/F filters and rinsed with distilled water. The filters were placed in Petri dishes and frozen for later analysis. Suspended sediment filters were dried overnight at 60°C and weighed. The filters were then combusted at 400°C for 12 hours and weighed. The weights of the total suspended, organic and inorganic materials were derived.; Data Quality Method: Suspended sediment concentrations were supervised and quality controlled by Nancy Rabalais. Visual inspection was conducted on all data for values +/- 2 SD of mean and inconsistent with others in a continuous string..
  • Parameter or Variable: Surface Photosynthetic Active Radiation (PAR) (measured); Units: microEinsteins/meter^2*sec; Observation Category: in situ; Sampling Instrument: Biospherical Instruments Surface PAR QSR2200; Sampling and Analyzing Method: The SeaBird CTD number of scans to average in the deck unit was set to one. At the beginning of each hydrocast, the entire CTD/Rosette package was soaked while submerged 0.5m to 1.0m below the surface until pump flow and oxygen values observed via the Sea-Bird deck unit indicated the system was operating correctly. Sensor packages are located below the Niskin bottle rosette sampler. In order to minimize the effect of delays in oxygen sensor response time caused by temperature, sensor condition and plumbing configuration, the CTD package was lowered and raised as close to dead slow as possible. The sensor packages were located below the Niskin bottles and rosette. Sea-Bird CTD data were acquired using Seasoft and processed using SBE Data Processing-Win32 software. All scans were processed without averaging or interpolation with a bin size of one scan. In order to compensate for the delay in oxygen sensor response time and improve the alignment between oxygen sensor values and temperature and conductivity sensor values, the Seasoft module ALIGNCTD was used. Stations used for alignment were those where the structure of the oxygen profile contained dominant features. After alignment, the DERIVE function was used to calculate Depth (m), Salinity (psu), Density sigma-t (kg/m3), Oxygen concentration (mg/L), and Oxygen percent saturation (%). Final data were exported as ascii files. A MATLAB program was then used to select a water column profile made up of scans from the downcast of discrete 1-meter (or 0.1-m) measurements from the ascii files. The MATLAB program selected scans as follows: 1) Data from Seabird warm up period sitting on the surface were removed; 2) Upcast data were removed; 3) Data scans were selected at 1.0 meter increments through the water column; 3) When D.O. values changed significantly (> 1.0 mgO2/L) within 1-meter, scans at 0.1-m intervals were selected within that meter; 4) Minimum oxygen and maximum depth scans were selected.; Data Quality Method: The Biospherical Instruments Surface PAR sensor was factory tested and calibrated at manufacturer recommended intervals and maintained and serviced by RV Pelican Electronic Technical support staff. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of the range of the instrument. N.B. Operations were conducted 24-hrs a day and as such, some irradiance values reflect nighttime values. In order to make this clear, irradiance values are provided as in-water and surface PAR data as well as the calculated % Irradiance calculated as the percentage of light from the surface observed at that depth in the water column (in-water PAR / surface PAR * 100)..
  • Parameter or Variable: LIGHT PENETRATION (calculated); Units: %; Observation Category: in situ; Sampling Instrument: Biospherical Instruments QSP-2300 and QSR2200; Sampling and Analyzing Method: The SeaBird CTD number of scans to average in the deck unit was set to one. At the beginning of each hydrocast, the entire CTD/Rosette package was soaked while submerged 0.5m to 1.0m below the surface until pump flow and oxygen values observed via the Sea-Bird deck unit indicated the system was operating correctly. Sensor packages are located below the Niskin bottle rosette sampler. In order to minimize the effect of delays in oxygen sensor response time caused by temperature, sensor condition and plumbing configuration, the CTD package was lowered and raised as close to dead slow as possible. The sensor packages were located below the Niskin bottles and rosette. Sea-Bird CTD data were acquired using Seasoft and processed using SBE Data Processing-Win32 software. All scans were processed without averaging or interpolation with a bin size of one scan. In order to compensate for the delay in oxygen sensor response time and improve the alignment between oxygen sensor values and temperature and conductivity sensor values, the Seasoft module ALIGNCTD was used. Stations used for alignment were those where the structure of the oxygen profile contained dominant features. After alignment, the DERIVE function was used to calculate Depth (m), Salinity (psu), Density sigma-t (kg/m3), Oxygen concentration (mg/L), and Oxygen percent saturation (%). Final data were exported as ascii files. A MATLAB program was then used to select a water column profile made up of scans from the downcast of discrete 1-meter (or 0.1-m) measurements from the ascii files. The MATLAB program selected scans as follows: 1) Data from Seabird warm up period sitting on the surface were removed; 2) Upcast data were removed; 3) Data scans were selected at 1.0 meter increments through the water column; 3) When D.O. values changed significantly (> 1.0 mgO2/L) within 1-meter, scans at 0.1-m intervals were selected within that meter; 4) Minimum oxygen and maximum depth scans were selected.; Data Quality Method: The Biospherical Instruments QSP-2300 in water PAR and QSR2200 Surface PAR sensors were factory tested and calibrated at manufacturer recommended intervals and maintained and serviced by RV Pelican Electronic Technical support staff. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of the range of the instrument. N.B. Operations were conducted 24-hrs a day and as such, some irradiance values reflect nighttime values. In order to make this clear, irradiance values are provided as in-water and surface PAR data as well as the calculated % Irradiance calculated as the percentage of light from the surface observed at that depth in the water column (in-water PAR / surface PAR * 100). Throughout the dataset, Irradiance values > 100% were removed as these values are the result of the sensor breaching the sea surface..
  • Parameter or Variable: pH mV (measured); Units: mV; Observation Category: in situ; Sampling Instrument: YSI - handheld multi-parameter instrument; Sampling and Analyzing Method: The YSI CTD was attached by chain to a lead weight. The weight was lowered to the bottom by hydrowire. With the weight on the bottom, the sonde was positioned approximately 0.5 meters above the bottom. When the oxygen sensor stabilized, a data record of all the sensor values was stored electronically. During the Shelfwide cruise, the sonde was raised in approximately 0.5-meter increments, after D.O. sensor stabilization on the bottom; data records were stored. After storing data for the few meters closest to the bottom, the sonde was raised to two to three meters from the surface and a data record was saved. The sonde was raised and records stored in approximately 0.5-meter increments until finally a record was stored with the sonde submerged but as close as possible to the surface.; Data Quality Method: pH mV data are not included in the 2018 dataset as the data returned were not reliable..
  • Parameter or Variable: pH (measured); Units: unitless; Observation Category: in situ; Sampling Instrument: SBE 27 pH/O.R.P (Redox) sensor; Sampling and Analyzing Method: The SeaBird CTD number of scans to average in the deck unit was set to one. At the beginning of each hydrocast, the entire CTD/Rosette package was soaked while submerged 0.5m to 1.0m below the surface until pump flow and oxygen values observed via the Sea-Bird deck unit indicated the system was operating correctly. Sensor packages are located below the Niskin bottle rosette sampler. In order to minimize the effect of delays in oxygen sensor response time caused by temperature, sensor condition and plumbing configuration, the CTD package was lowered and raised as close to dead slow as possible. The sensor packages were located below the Niskin bottles and rosette. Sea-Bird CTD data were acquired using Seasoft and processed using SBE Data Processing-Win32 software. All scans were processed without averaging or interpolation with a bin size of one scan. In order to compensate for the delay in oxygen sensor response time and improve the alignment between oxygen sensor values and temperature and conductivity sensor values, the Seasoft module ALIGNCTD was used. Stations used for alignment were those where the structure of the oxygen profile contained dominant features. After alignment, the DERIVE function was used to calculate Depth (m), Salinity (psu), Density sigma-t (kg/m3), Oxygen concentration (mg/L), and Oxygen percent saturation (%). Final data were exported as ascii files. A MATLAB program was then used to select a water column profile made up of scans from the downcast of discrete 1-meter (or 0.1-m) measurements from the ascii files. The MATLAB program selected scans as follows: 1) Data from Seabird warm up period sitting on the surface were removed; 2) Upcast data were removed; 3) Data scans were selected at 1.0 meter increments through the water column; 3) When D.O. values changed significantly (> 1.0 mgO2/L) within 1-meter, scans at 0.1-m intervals were selected within that meter; 4) Minimum oxygen and maximum depth scans were selected.; Data Quality Method: The SBE 27 pH/O.R.P (Redox) sensor was factory tested and calibrated at manufacturer recommended intervals and maintained and serviced by RV Pelican Electronic Technical support staff. Visual inspection was conducted on all data for values +/- 2 SD of mean, inconsistent with others in a continuous string, and outside of the range of the instrument. Note O.R.P. data are not included as those values were not reliable..
Acquisition Information (collection)
Instrument
  • multi-parameter water quality sensor
  • Secchi disk
Platform
  • R/V Pelican
Last Modified: 2024-02-28T13:48:22Z
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