Processing Steps |
- Parameter or Variable: Dissolved Inorganic Carbon; Abbreviation: DIC_UMOL_KG; Unit: micromoles/kg; Observation type: discrete water sample; In-situ / Manipulation / Response variable: in-situ observation; Measured or calculated: Measured; Calculation method and parameters: none; Sampling instrument: Niskin bottle - transferred to Borosilicate bottle; Analyzing instrument: SOMMA (Single Operator Multiparameter Metabolic Analyzer) systems, PMEL1 and PMEL2, each utilizing a 5011 coulometer (UIC, Inc.). The SOMMA systems were originally developed by Ken Johnson (Johnson et al.,1985,1987,1993; Johnson,1992; Wilke et al., 1993) of Brookhaven National Laboratory (BNL). For a portion of the samples (SAMPLE_ID's #4120-4212) two systems consisting of a coulometer (UIC Inc.) coupled with a Dissolved Inorganic Carbon Extractor (DICE) inlet system were used. DICE was developed by Esa Peltola and Denis Pierrot of NOAA/AOML and Dana Greeley of NOAA/PMEL to modernize a carbon extractor called SOMMA (Johnson et al. 1985, 1987, 1993, and 1999; Johnson 1992).; Detailed sampling and analyzing information: Analyses conducted at NOAA PMEL. Measurements drawn according to procedures in the Guide to Best Practices for Ocean CO2 Measurements (Dickson et al., 2007). Borosilicate bottle were rinsed and filled from bottom, leaving a minimal amount of headspace while making sure no bubbles were introduced. Then 0.2 ml of saturated HgCl2 solution was added, bottles were sealed with glass stoppers lightly covered with Apiezon-L grease, and were stored at room temperature to be sent to PMEL for analysis.; Standardization description: Each coulometer was calibrated by injecting aliquots of pure CO2 (99.999%) by means of an 8-port valve (Wilke et al. 1993) outfitted with two calibrated sample loops of different sizes (~1 mL and ~2 mL). The instruments were each separately calibrated at the beginning of each cell with a minimum of two sets of these gas loop injections.; Standardization frequency: 1) Gas loops were run near the beginning of each cell; 2) CRMs supplied by Dr. A. Dickson of SIO, were also measured near the beginning; and 3) Duplicate samples were typically run throughout the life of the cell solution.; CRM manufacturer: Andrew Dickson's lab at Scripps Institute of Oceanography; Preservation method: Saturated Mercuric Chloride (HgCl2) Solution; Preservative volume: 0.2 ml; Preservative correction: The DIC values were corrected for dilution by 0.2 ml of saturated HgCl2 used for sample preservation. The total water volume of the sample bottles was 540 ml. The correction factor used for dilution was 1.00037.; Uncertainty: +/- 0.1%; Quality flag convention: WOCE water sample quality flag; Method reference: Dickson, A.G., Sabine, C.L. and Christian, J.R. (Eds.) 2007. Guide to best practices for ocean CO2 measurements. PICES Special Publication 3, 191 pp.; Researcher name: Dana Greeley, Julian Herndon, and Morgan Ostendorf (contact PI Simone Alin for all inquiries); Researcher institution: Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration; and Cooperative Institute for Climate, Ocean, and Ecosystem Studies, University of Washington.
- Parameter or Variable: Total alkalinity; Abbreviation: TALK_UMOL_KG; Unit: micromoles/kg; Observation type: Discrete measurements from samples collected on CTD casts; In-situ / Manipulation / Response variable: in-situ observation; Measured or calculated: Measured; Calculation method and parameters: none; Sampling instrument: Niskin bottle - transferred to Borosilicate bottle; Analyzing instrument: Custom instrument, built at PMEL and modeled after an earlier generation of those made in Dr. Andrew Dickson's laboratory at Scripps Oceanographic Institution.; Type of titration: Two-stage, potentiometric, open-cell titration using coulometrically analyzed hydrochloric acid.; Cell type (open or closed): Open; Curve fitting method: Non-linear least squares; Detailed sampling and analyzing information: Analyses conducted at PMEL. Samples run using remaining water from the same sample bottles used for DIC. Seawater total alkalinity (TA) was measured by acidimetric titration. The specific method used was based upon the open-cell method described by Dickson et al (2003). This method involves first acidifying the sample to reduce the sample pH of just over 3.5 followed by bubbling CO2-free air through the sample to facilitate removal of the CO2 evolved by the acid addition. After removal of the carbonate species from solution, the titration proceeds until a pH of just below 3.0 is attained, and the equivalence point evaluated from titration points in the pH region 3.0 - 3.5 using a non-linear least squares procedure that corrects for the reactions with sulfate and fluoride ions (Dickson et al. 2003). Titration progress is monitored by measuring the electromotive force (E) of a combination glass-reference electrode. Samples were drawn from the Niskin-type bottles into cleaned 500-ml borosilicate glass bottles using Tygon tubing with silicone ends. Bottles were rinsed three times and filled from the bottom, overflowing half a volume and taking care not to entrain any bubbles. The sample tube was closed off and withdrawn from the sample bottle, creating a 5 ml headspace. Samples were preserved by poisoning with 0.2 ml of a saturated HgCl2 solution. Sample bottles were sealed with glass stoppers lightly coated with Apiezon-L grease, and were stored in an air-conditioned laboratory on the research vessel. Samples were shipped to PMEL following cruise completion, and were stored at room temperature (21 - 25 degC) for a maximum of 12 hours prior to analysis. Titrations were carried out in water-jacketed, 250-ml beakers. The beakers were kept at 24.0 +/- 0.2 degC with water from a constant temperature bath. Prior to analysis, samples were placed in the water bath to bring them to the same temperature as the reaction beakers. Seawater samples were dispensed into the water-jacketed beaker using a fixed-volume glass syringe. A Metrohm Dosimat 765 was used to deliver acid to the sample beaker in increments of 0.040 ml. The acid titrant used was 0.1 mol/kg HCl prepared in 0.6 mol/kg NaCl background to approximate the ionic strength of seawater (0.7 mol/kg). Instrument control and data acquisition was with custom software developed in Andrew Dickson's laboratory at Scripps Institution of Oceanography and modified by a former employee of the NOAA/PMEL Carbon Group using the National Instruments LabView programming environment. Typical titrations were completed in 10-14 minutes and required 20-24 acid additions to reach a pH of 3.0.; Standardization description: Duplicate samples are run in addition to Certified Reference Material (CRM), supplied by Dr. A. Dickson of UCSD; Standardization frequency: Along with duplicate samples being run throughout, CRMs are run at the beginning and end of each sampling period; CRM manufacturer: Andrew Dickson's lab at Scripps Institute of Oceanography; Preservation method: Saturated Mercuric Chloride (HgCl2) Solution; Preservative volume: 0.2 ml; Preservative correction: The TA values were corrected for the resulting dilution of the added 0.2 ml of saturated HgCl2 used for sample preservation.; TA blank correction: NA; Uncertainty: +/- 0.1%; Quality flag convention: WOCE water sample quality flag; Method reference: Bates, R.G. Determination of pH. Theory and Practice. A Wiley-Interscience Publication, Second Edition. Dickson A.G. (1981). An exact definition of total alkalinity, and a procedure for the estimation of alkalinity and total inorganic carbon from titration data. Deep-Sea Res. 28, 609-623. Dickson A.G. (1992). The development of the alkalinity concept in marine chemistry. Marine chemistry 40:1-21-2, 49-63. Dickson, A. G., Afghan, J. D. and Anderson, G. C. (2003). Reference materials for oceanic CO2 analysis: A method for the certification of total alkalinity. Marine Chemistry 80, 185-197 Gran G. (1952). Determination of the equivalence point in potentiometric titrations. Part II. The analyst, 77, 661-671. Wolf-Gladrow, D.A. et al. (2007). Total alkalinity: The explicit conservative expression and its application to biogeochemical process.; Researcher name: Morgan Ostendorf and Julian Herndon; PIs: Simone Alin and Richard Feely; Researcher institution: Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration; and Cooperative Institute for Climate, Ocean, and Ecosystem Studies, University of Washington.
- Parameter or Variable: pH; Abbreviation: pH_TS_CALCULATED; pH scale: Total scale; Observation type: discrete water sample; In-situ / Manipulation / Response variable: in-situ observation; Measured or calculated: calculated; Calculation method and parameters: R package - seacarb. DIC, TALK, T, S, P; Sampling instrument: NA; Analyzing instrument: NA; Temperature of pH measurement: in-situ observation; Detailed sampling and analyzing information: Refer to DIC for more information on sampling and conservation of samples.; Standardization description: NA - calculated; Standardization frequency: NA - calculated; pH standard values: NA - calculated; Temperature of standardization: NA - calculated; Temperature correction method: NA - calculated; At what temperature was pH reported: in-situ temperature; Method reference: Refer to DIC for more information on sampling and conservation of samples.; Researcher name: Hannah Barkley; Researcher institution: NMFS/PIFSC/ESD.
- Parameter or Variable: pCO2 (fCO2) autonomous; Abbreviation: pCO2_UATM_CALCULATED; Unit: microatmospheres; Observation type: discrete water sample; In-situ / Manipulation / Response variable: in-situ observation; Measured or calculated: calculated; Calculation method and parameters: R package - seacarb. DIC, TALK, T, S, P; Sampling instrument: NA; Location of seawater intake: NA - calculated; Analyzing instrument: NA - calculated; Detailed sampling and analyzing information: NA - calculated; Equilibrator type: NA - calculated; Equilibrator volume: NA - calculated; Is the equilibrator vented or not: NA - calculated; Water flow rate: NA - calculated; Gas flow rate: NA - calculated; How was temperature inside the equilibrator measured: NA - calculated; How was pressure inside the equilibrator measured: NA - calculated; Drying method for gas: NA - calculated; SEA CO2 gas detector manufacturer: NA - calculated; SEA CO2 gas detector model: NA - calculated; SEA CO2 gas detector resolution: NA - calculated; SEA CO2 gas detector uncertainty: NA - calculated; Standardization technique: NA - calculated; Standardization frequency: NA - calculated; Standard gas manufacturer: NA - calculated; Standard gas concentration: NA - calculated; Standard gas uncertainty: NA - calculated; Water vapor correction method: NA - calculated; Temperature correction method: NA - calculated; At what temperature was pCO2 reported: NA - calculated; Method reference: Refer to DIC for more information on sampling and conservation of samples.; Researcher name: Hannah Barkley; Researcher institution: NMFS/PIFSC/ESD.
- Parameter or Variable: Hydrostatic pressure recorded from CTD at the depth where the sample was taken.; Abbreviation: PRESSURE_DB_CTD; Unit: decibar; Observation type: CTD Profile; In-situ / Manipulation / Response variable: in-situ observation; Measured or calculated: measured; Sampling instrument: NA; Analyzing instrument: Seabird Electronics 19+ CTD; Duration: one-time measurement; Uncertainty: +/- 0.1%; Researcher name: Hannah Barkley; Researcher institution: NMFS/PIFSC/ESD.
- Parameter or Variable: Pressure calculated from depth (using the R package "oce") for samples not associated with a CTD cast.; Abbreviation: PRESSURE_DB_CALCULATED; Unit: decibar; Measured or calculated: Pressure was calculated from depth using the R package "oce"; Duration: one-time measurement; Researcher name: Hannah Barkley; Researcher institution: NMFS/PIFSC/ESD.
- Parameter or Variable: Depth at which sample was collected.; Abbreviation: DEPTH_METER; Unit: meters; Measured or calculated: measured; Sampling instrument: Dive computer or marked niskin line.; Duration: one-time measurement; Detailed sampling and analyzing information: Sample depth was measured using either a dive computer (for benthic samples collected on SCUBA) or a marked niskin line (for surface samples collected from a small boat). For benthic samples, depth was recorded off of a wrist-mounted dive computer held adjacent to the niskin as it was triggered. For surface samples, depth was measured using 1m increments marked on the niskin line.; Researcher name: Hannah Barkley; Researcher institution: NMFS/PIFSC/ESD.
- Parameter or Variable: In situ temperature recorded from CTD with the scale of ITS-90.; Abbreviation: TEMPERATURE_ITS90_CTD; Unit: degrees Celsius; Observation type: CTD Profile; In-situ / Manipulation / Response variable: in-situ observation; Measured or calculated: measured; Sampling instrument: Seabird Electronics 19+ CTD; Duration: one-time measurement; Uncertainty: +/- 0.005 degrees Celsius; Quality flag convention: WOCE CTD quality flag; Researcher name: Hannah Barkley; Researcher institution: NMFS/PIFSC/ESD.
- Parameter or Variable: Temperature recorded by the Scientific Computer System (SCS) with the scale of ITS-90.; Abbreviation: TEMPERATURE_ITS90_SCS; Unit: degrees Celsius; Observation type: surface underway; In-situ / Manipulation / Response variable: in-situ observation; Measured or calculated: measured; Analyzing instrument: SeaBird 38 Digital External Thermometer; Duration: one-time measurement; Detailed sampling and analyzing information: Temperature was measured by an externally mounted SBE 38 Digital Oceanographic Thermometer, located on the forward hull of the NOAA ship Hi'ialakai adjacent to the starboard side bow thruster at 2m depth. SCS values for temperature were only used for nearshore water samples if no other in-situ temperature data were available, and were calculated from the SCS time series at the same TIMESTAMP_UTC as the sample.; Uncertainty: +/- 0.001 degrees Celsius (SBE38). Shipboard SCS temperature data, collected offshore of the reef, are spatially separated from the location of nearshore water sample data, collected by small boats, and may not accurately reflect nearshore conditions.; Researcher name: Hannah Barkley; Researcher institution: NMFS/PIFSC/ESD.
- Parameter or Variable: Salinity calculated from conductivity recorded by CTD using the equation of the Practical Salinity Scale of 1978; Abbreviation: SALINITY_PSS78_CTD; Observation type: CTD Profile; In-situ / Manipulation / Response variable: in-situ observation; Measured or calculated: measured; Analyzing instrument: Seabird Electronics 19+ CTD; Duration: one-time measurement; Uncertainty: +/- 0.0005 S/m; Quality flag convention: WOCE CTD quality flag; Researcher name: Hannah Barkley; Researcher institution: NMFS/PIFSC/ESD.
- Parameter or Variable: Salinity calculated from conductivity measured from discrete bottles using the equation of the Practical Salinity Scale of 1978; Abbreviation: SALINITY_PSS78_BOTTLE; Unit: 1978 Practical Salinity Scale; Measured or calculated: Measured and Calculated - see Detailed Sampling Information; Calculation method and parameters: Measured values corrected to average offset of CTD and bottle samples; Sampling instrument: 500ml borosilicate glass bottle; Analyzing instrument: Seabird SBE4, modified to connect with the SOMMA systems PMEL1 and PMEL2.; Detailed sampling and analyzing information: These SBE4 salinity values are designed to be used only for the density correction to the SOMMA pipettes. The numbers provided for these 3 samples (flask 42 to 44) were corrected from the measured value by the average offset which was 0.087.; Replicate information: None; Uncertainty: The uncertainty could be as much as plus or minus 0.5. As an example, if one were to increase salinity by 0.5, then the CO2sys calculated pH would drop by ~0.006, pCO2 rises up by 6, WAragonite goes down by 0.001. Bottle salinity values are only used if CTD salinity data are not available.; Quality flag convention: WOCE water sample quality flag; Researcher name: Dana Greeley, Julian Herndon, and Morgan Ostendorf (contact PI Simone Alin for all inquiries); Researcher institution: Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration; and Joint Institute for the Study of the Atmosphere and Ocean, University of Washington.
- Parameter or Variable: Salinity recorded by the Scientific Computer System (SCS) using the equation of the Practical Salinity Scale of 1978.; Abbreviation: SALINITY_PSS78_SCS; Unit: Practical Salinity Scale of 1978; Observation type: surface underway; In-situ / Manipulation / Response variable: in-situ observation; Measured or calculated: measured; Analyzing instrument: Seabird Electronics 45 MicroTSG Thermosalinograph; Duration: one-time measurement; Detailed sampling and analyzing information: Salinity was measured by a SBE45 MicroTSG Thermosalinograph installed in the wet lab of the NOAA ship Hi'ialakai. The wetlab seawater intake was located ~70m below the wet lab deck near the middle of the ship at depth 2m. SCS values for salinity were only used for nearshore water samples if no other in-situ salinity data were available, and were calculated from the SCS time series at the same TIMESTAMP_UTC as the sample.; Uncertainty: +/- 0.0003 S/m (SBE45). Shipboard SCS salinity data, collected offshore of the reef, are spatially separated from the location of nearshore water sample data, collected by small boats, and may not accurately reflect nearshore conditions.; Researcher name: Hannah Barkley; Researcher institution: NMFS/PIFSC/ESD.
- Parameter or Variable: Aragonite saturation state calculated from DIC and TALK; Abbreviation: ARAGONITE_SAT; In-situ / Manipulation / Response variable: in-situ observation; Measured or calculated: calculated; Calculation method and parameters: R package - seacarb. DIC, TA, T, S, P; Duration: one-time measurement; Researcher name: Hannah Barkley; Researcher institution: NMFS/PIFSC/ESD.
- Parameter or Variable: Best temperature value associated with the sample (degrees Celsius), derived from either TEMPERATURE_ITS90_CTD or TEMPERATURE_ITS90_SCS; Abbreviation: TEMPERATURE_ITS90_BEST.
- Parameter or Variable: Best salinity value associated with the sample (PSU), derived from either SALINITY_PSS78_CTD, SALINITY_PSS78_BOTTLE, or SALINITY_PSS78_SCS.; Abbreviation: SALINITY_PSS78_BEST.
- Parameter or Variable: An identifier for the station at the island or atoll (LOCATION) associated with the sample. Combines a 3-letter island code (derived from LOCATIONCODE) with a 2-4 digit site number.; Abbreviation: STATION_ID.
- Parameter or Variable: Cast number, where a cast is the lowering of equipment over the side at one station (STATION_ID). Cast_number is sequential and starts with 1 for each station.; Abbreviation: CAST_NUMBER.
- Parameter or Variable: Unique numeric identifer for each water sample (4-digit number).; Abbreviation: SAMPLE_ID.
- Parameter or Variable: Calendar year in UTC of sample.; Abbreviation: YEAR_UTC.
- Parameter or Variable: Calendar month in UTC of sample.; Abbreviation: MONTH_UTC.
- Parameter or Variable: Calendar day in UTC of sample.; Abbreviation: DAY_UTC.
- Parameter or Variable: Time in UTC (hh:mm:ss) of sample.; Abbreviation: TIME_UTC.
- Parameter or Variable: Day number of sample in an annual cycle.; Abbreviation: YEARDAY_UTC.
- Parameter or Variable: Unique numeric ID of CTD cast (4-digit number).; Abbreviation: CTDCASTID_ESD.
- Parameter or Variable: An identifier for the fixed NCRMP climate site associated with the sample, if any. An OCC_SITEID is a 3-dimensional identifier that describes a location (LATITUDE and LONGITUDE) and depth of a fixed climate site and includes "OCC" prefix, a 3-letter location code (derived from LOCATIONCODE), and a 3-digit site number. A sample is assigned an ASSOC_OCC_SITEID only if its coordinates (LATITUDE and LONGITUDE) are within a 150-m radius of a pre-existing OCC_SITEID; otherwise, no ASSOC_OCC_SITEID is assigned.; Abbreviation: ASSOC_OCC_SITEID.
- Parameter or Variable: The name of the region where the CTD cast was conducted in the Pacific Islands region: American Samoa, Pacific Remote Island Areas, Mariana Archipelago, main Hawaiian Islands, Northwestern Hawaiian Islands.; Abbreviation: REGION.
- Parameter or Variable: Code for REGION.; Abbreviation: REGIONCODE.
- Parameter or Variable: Name of island or atoll where the sample was collected in the Pacific Islands region (REGION).; Abbreviation: LOCATION.
- Parameter or Variable: 3-Letter unique code for LOCATION.; Abbreviation: LOCATIONCODE.
- Parameter or Variable: NCRMP survey design associated with the sample. Survey designs include: samples collected at permanent climate sites (Permanent); samples co-located with fish or benthic stratified random survey sites (Stratified_Random); samples at random sites not associated with climate, benthic, or fish sites (Random); samples conducted offshore to collect end member data (End_member); and samples collected to calibrate underway systems (Calibration).; Abbreviation: SURVEY_DESIGN.
- Parameter or Variable: Indicates if water sample is discrete (Single) or if the sample is part a series of water samples collected ~every 4 hrs in a ~24-hr period at the same STATION_ID using a Programmable Underwater Collector (Diel).; Abbreviation: SAMPLE_FREQUENCY.
- Parameter or Variable: Source of 'TEMPERATURE_ITS90_BEST' measurement: CTD (TEMPERATURE_ITS90_CTD) or SCS (TEMPERATURE_ITS90_SCS); Abbreviation: TEMPERATURE_ITS90_BEST_ORIGIN.
- Parameter or Variable: Source of 'SALINITY_PSS78_BEST' measurement: CTD (SALINITY_PSS78_CTD), discrete bottle sample (SALINITY_PSS78_BOTTLE), or SCS (SALINITY_PSS78_SCS); Abbreviation: SALINITY_PSS78_BEST_ORIGIN.
- Parameter or Variable: Date and time of water sample in UTC; Abbreviation: TIMESTAMP_UTC.
- Parameter or Variable: Latitude in decimal degrees North (negative for southern hemisphere) for sample.; Abbreviation: LATITUDE_DEC.
- Parameter or Variable: Longitude in decimal degrees East (negative for western hemisphere) for sample.; Abbreviation: LONGITUDE_DEC.
- Parameter or Variable: WOCE CTD quality flag; Abbreviation: TEMPERATURE_ITS90_CTD_FLAG.
- Parameter or Variable: WOCE CTD quality flag; Abbreviation: SALINITY_PSS78_CTD_FLAG.
- Parameter or Variable: WOCE water sample quality flag; Abbreviation: SALINITY_PSS78_BOTTLE_FLAG.
- Parameter or Variable: WOCE water sample quality flag; Abbreviation: DIC_UMOL_KG_FLAG.
- Parameter or Variable: WOCE water sample quality flag; Abbreviation: TALK_UMOL_KG_FLAG .
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