Dataset Overview | National Centers for Environmental Information (NCEI)

Discrete profile measurements of dissolved inorganic carbon, total alkalinity, pH on total scale and other hydrographic and chemical parameters obtained during R/V Nathaniel B. Palmer Repeat Hydrography and SOCCOM Cruise NBP18_02 in the Pacific Sector of Southern Ocean: GO-SHIP Section S04P (EXPOCODE 320620180309), from 2018-03-09 to 2018-05-14 (NCEI Accession 0225497)

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This dataset includes discrete profile measurements of dissolved inorganic carbon, total alkalinity, pH (on total scale), water temperature, salinity, dissolved oxygen, nitrate, nitrite, silicate, phosphate, chlorofluorocarbons and other chemical measurements during the R/V Nathaniel B. Palmer Repeat Hydrography and SOCCOM Cruise NBP18_02 in the Pacific Sector of Southern Ocean: GO-SHIP Section S04P (EXPOCODE 320620180309), from 2018-03-09 - 2018-05-14. The Pacific Ocean S04P repeat hydrographic line was reoccupied for the US Global Ocean Carbon and Repeat Hydrography Program. The survey of S04P 2018 consisted of CTDO, rosette, LADCP, UVP, water samples and underway measurements. The ship departed from the port of Hobart on the island of Tasmania, Australia and completed the cruise in the port of Punta Arenas, Chile.

Dataset Citation

Cite as: Macdonald, Alison M.; Wanninkhof, Rik; Dickson, Andrew G.; Swift, James H.; Carlson, Craig A.; Key, Robert M.; McNichol, Ann; Warner, Mark J.; Straneo, Fiamma (2021). Discrete profile measurements of dissolved inorganic carbon, total alkalinity, pH on total scale and other hydrographic and chemical parameters obtained during R/V Nathaniel B. Palmer Repeat Hydrography and SOCCOM Cruise NBP18_02 in the Pacific Sector of Southern Ocean: GO-SHIP Section S04P (EXPOCODE 320620180309), from 2018-03-09 to 2018-05-14 (NCEI Accession 0225497). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.25921/8arx-2058. Accessed [date].

Dataset Identifiers

ISO 19115-2 Metadata

gov.noaa.nodc:0225497

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Ordering Instructions	Contact NCEI for other distribution options and instructions.
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	2018-03-09 to 2018-05-14
Spatial Bounding Box Coordinates	West: 159.15 East: -73.5 South: -75.29 North: 59.62
Spatial Coverage Map

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Associated Resources

CLIVAR/GO-SHIP Repeat Section S04P
- https://www.ncei.noaa.gov/access/ocean-carbon-acidification-data-system/oceans/RepeatSections/clivar_S04P.html
  related resource
NOAA National Centers for Environmental Information (2022). Ocean Carbon and Acidification Data System (OCADS). NOAA National Centers for Environmental Information. https://www.ncei.noaa.gov/products/ocean-carbon-acidification-data-system
- https://www.ncei.noaa.gov/products/ocean-carbon-acidification-data-system
  OCADS website

Publication Dates	publication: 2021-02-19 revision: 2021-03-18
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	In this accession, NCEI has archived multiple versions of these data. The latest (and best) version of these data has the largest version number.
Purpose	This dataset is available to the public for a wide variety of uses including scientific research and analysis.
Use Limitations	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: Macdonald, Alison M.; Wanninkhof, Rik; Dickson, Andrew G.; Swift, James H.; Carlson, Craig A.; Key, Robert M.; McNichol, Ann; Warner, Mark J.; Straneo, Fiamma (2021). Discrete profile measurements of dissolved inorganic carbon, total alkalinity, pH on total scale and other hydrographic and chemical parameters obtained during R/V Nathaniel B. Palmer Repeat Hydrography and SOCCOM Cruise NBP18_02 in the Pacific Sector of Southern Ocean: GO-SHIP Section S04P (EXPOCODE 320620180309), from 2018-03-09 to 2018-05-14 (NCEI Accession 0225497). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.25921/8arx-2058. Accessed [date].
Cited Authors	Macdonald, Alison M. Woods Hole Oceanographic Institution (WHOI) Wanninkhof, Rik Dickson, Andrew G. Scripps Institution of Oceanography (SIO) Swift, James H. Scripps Institution of Oceanography Carlson, Craig A. UC Santa Barbara Key, Robert M. Princeton University McNichol, Ann Warner, Mark J. Straneo, Fiamma Woods Hole Oceanographic Institution
Principal Investigators	Alison M. Macdonald Woods Hole Oceanographic Institution (WHOI) Rik Wanninkhof US DOC; NOAA; OAR; Atlantic Oceanographic and Meteorological Laboratory (AOML) Craig A. Carlson University of California - Santa Barbara (UCSB) Andrew G. Dickson University of California - San Diego; Scripps Institution of Oceanography (SIO)
Contributors	Princeton University US DOC; NOAA; OAR; Atlantic Oceanographic and Meteorological Laboratory (AOML) Woods Hole Oceanographic Institution (WHOI) US DOC; NOAA; OAR; Pacific Marine Environmental Laboratory (PMEL) University of California - San Diego; Scripps Institution of Oceanography (SIO)
Resource Providers	Robert M. Key Princeton University Princeton University
Publishers	NOAA National Centers for Environmental Information
Acknowledgments	Funding Information: NOAA, NSF (GO-SHIP Program)

Theme keywords	NODC DATA TYPES THESAURUS CHLOROFLUOROCARBON-11 (CFC-11) CHLOROFLUOROCARBON-12 (CFC-12) DELTA CARBON-13 DELTA CARBON-14 DISSOLVED INORGANIC CARBON (DIC) DISSOLVED ORGANIC CARBON DISSOLVED OXYGEN NITRATE NITRITE pH phosphate SALINITY silicate sulfur hexafluoride (SF6) total alkalinity WATER TEMPERATURE NODC OBSERVATION TYPES THESAURUS chemical discrete sample physical profile WMO_CategoryCode oceanography Global Change Master Directory (GCMD) Science Keywords EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > ALKALINITY EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > INORGANIC CARBON EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > NITRATE EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > NITRITE EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > ORGANIC CARBON EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > OXYGEN EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > PH EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > PHOSPHATE EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > SILICATE EARTH SCIENCE > OCEANS > OCEAN TEMPERATURE > WATER TEMPERATURE EARTH SCIENCE > OCEANS > SALINITY/DENSITY > SALINITY OCADS Study Type Discrete measurement Profile Provider Keywords GO-SHIP Nathaniel B. Palmer Repeat Hydrographic Sections S04P SOCCOM Provider Variable Abbreviations ALKALI CFC-11 CFC-12 CHLORA CTDOXY CTDSAL CTDTMP DELC13 DELC14 DOC NITRAT NITRIT OXYGEN PHSPHT PH_TMP PH_TOT SALNTY SF6 SILCAT TCARBN TDN
Data Center keywords	NODC COLLECTING INSTITUTION NAMES THESAURUS Princeton University University of California - San Diego; Scripps Institution of Oceanography US DOC; NOAA; OAR; Atlantic Oceanographic and Meteorological Laboratory US DOC; NOAA; OAR; Pacific Marine Environmental Laboratory Woods Hole Oceanographic Institution NODC SUBMITTING INSTITUTION NAMES THESAURUS Princeton University Global Change Master Directory (GCMD) Data Center Keywords DOC/NOAA/OAR/AOML > Atlantic Oceanographic and Meteorological Laboratory, OAR, NOAA, U.S. Department of Commerce DOC/NOAA/OAR/PMEL > Pacific Marine Environmental Laboratory, OAR, NOAA, U.S. Department of Commerce WHOI > WOODS HOLE OCEANOGRAPHIC INSTITUTION
Platform keywords	NODC PLATFORM NAMES THESAURUS RV Nathaniel B. Palmer Global Change Master Directory (GCMD) Platform Keywords Ships ICES/SeaDataNet Ship Codes NATHANIEL B. PALMER (call sign: WPB3210, ICES code: 3206, 1992)
Instrument keywords	NODC INSTRUMENT TYPES THESAURUS carbon dioxide (CO2) gas analyzer CTD Niskin bottle pH sensor salinometer temperature probe titrator Global Change Master Directory (GCMD) Instrument Keywords CO2 ANALYZERS > CO2 ANALYZERS CTD > Conductivity, Temperature, Depth NISKIN BOTTLES PH METERS > PH METERS SALINOMETERS TEMPERATURE PROBES > TEMPERATURE PROBES
Place keywords	NODC SEA AREA NAMES THESAURUS South Pacific Ocean Southern Ocean Global Change Master Directory (GCMD) Location Keywords OCEAN > PACIFIC OCEAN > SOUTH PACIFIC OCEAN OCEAN > SOUTHERN OCEAN Provider Geographic Names Pacific Ocean Southern Ocean
Project keywords	NODC PROJECT NAMES THESAURUS Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) The Global Ocean Ship-based Hydrographic Investigations Program (GO-SHIP) Cruise ID NBP18_02, SOCCOM EXPOCODE 320620180309 Ocean Acidification Search Keywords Ocean Carbon and Acidification Data System (OCADS) Project Reference Section ID S04P
Keywords	NCEI ACCESSION NUMBER 0225497

Use Constraints	Cite as: Macdonald, Alison M.; Wanninkhof, Rik; Dickson, Andrew G.; Swift, James H.; Carlson, Craig A.; Key, Robert M.; McNichol, Ann; Warner, Mark J.; Straneo, Fiamma (2021). Discrete profile measurements of dissolved inorganic carbon, total alkalinity, pH on total scale and other hydrographic and chemical parameters obtained during R/V Nathaniel B. Palmer Repeat Hydrography and SOCCOM Cruise NBP18_02 in the Pacific Sector of Southern Ocean: GO-SHIP Section S04P (EXPOCODE 320620180309), from 2018-03-09 to 2018-05-14 (NCEI Accession 0225497). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.25921/8arx-2058. 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.
Fees	In most cases, electronic downloads of the data are free. However, fees may apply for custom orders, data certifications, copies of analog materials, and data distribution on physical media.

Lineage information for: dataset
Processing Steps	2021-02-19T07:36:37Z - NCEI Accession 0225497 v1.1 was published. 2021-03-18T23:12:22Z - NCEI Accession 0225497 was revised and v2.2 was published. Rationale: Updates were received for this dataset. These updates were copied into the data/0-data/ directory of this accession. These updates may provide additional files or replace obsolete files. This version contains the most complete and up-to-date representation of this archival information package. All of the files received prior to this update are available in the preceding version of this accession.
Output Datasets	NCEI Accession 0225497 v1.1 NCEI Accession 0225497 v1.1 (download) published 2021-02-19T07:36:37Z NCEI Accession 0225497 v2.2 NCEI Accession 0225497 v2.2 (download) published 2021-03-18T23:12:22Z

Lineage information for: dataset

Processing Steps

2021-02-19T07:36:37Z - NCEI Accession 0225497 v1.1 was published.
2021-03-18T23:12:22Z - NCEI Accession 0225497 was revised and v2.2 was published.
Rationale: Updates were received for this dataset. These updates were copied into the data/0-data/ directory of this accession. These updates may provide additional files or replace obsolete files. This version contains the most complete and up-to-date representation of this archival information package. All of the files received prior to this update are available in the preceding version of this accession.

Output Datasets

NCEI Accession 0225497 v1.1
- NCEI Accession 0225497 v1.1 (download)
  published 2021-02-19T07:36:37Z

NCEI Accession 0225497 v2.2
- NCEI Accession 0225497 v2.2 (download)
  published 2021-03-18T23:12:22Z

Lineage information for: dataset
Processing Steps	Parameter or Variable: Dissolved Inorganic Carbon; Abbreviation: TCARBN; Unit: UMOL/KG; Observation type: discrete; Measured or calculated: Measured; Sampling instrument: Niskin Bottles; Analyzing instrument: SOMMA; Detailed sampling and analyzing information: DIC analysis was performed via coulometry using two analytical systems (PMEL1 and PMEL2) simultaneously on the cruise. Each system consisted of a coulometer (CM5015-O UIC Inc) coupled with a Dissolved Inorganic Carbon Extractor (DICE). The DICE system 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). In coulometric analysis of DIC, all carbonate species are converted to CO2 (gas) by addition of excess hydrogen ion (acid) to the seawater sample, and the evolved CO2 gas is swept into the titration cell of the coulometer with pure air or compressed nitrogen, where it reacts quantitatively with a proprietary reagent based on ethanolamine to generate hydrogen ions. In this process, the solution changes from blue to colorless, triggering a current through the cell and causing coulometrical generation of OH- ions at the anode. The OH- ions react with the H+, and the solution turns blue again. A beam of light is shone through the solution, and a photometric detector at the opposite side of the cell senses the change in transmission. Once the percent transmission reaches its original value, the coulometric titration is stopped, and the amount of CO2 that enters the cell is determined by integrating the total change during the titration.; Replicate information: Duplicate samples from the same niskin were measured near the beginning; middle and end of each cell.; CRM batch number: 172: Certified Value = 2039.06 μmol/kg; Preservation method: 0.12 ml of saturated HgCl2 used for sample preservation; Uncertainty: The precision of the two DICE systems can be demonstrated via the replicate samples. Approximately 11.5% of the niskins sampled were duplicates taken as a check of our precision. These replicate samples were interspersed throughout the station analysis for quality assurance and integrity of the coulometer cell solutions. The average absolute difference from the mean of these replicates is 0.67 μmol/kg - no major systematic differences between the replicates were observed.; Method reference: Johnson et al. 1985, 1987, 1993, and 1999; Johnson 1992; Researcher name: Rik Wanninkhof, Richard Feely; Researcher institution: NOAA/AOML; NOAA/PMEL. Parameter or Variable: Total alkalinity; Abbreviation: ALKALI; Unit: UMOL/KG; Observation type: discrete; Measured or calculated: Measured; Type of titration: two-stage open cell acidimetric, potentiometric; Cell type (open or closed): open cell titration; Detailed sampling and analyzing information: Seawater samples are analyzed using an open cell two-stage titration procedure using two 250 mL jacketed cells. One sample is undergoing titration while the second is being prepared and equilibrating to 20°C for analysis. The sample of seawater is first acidified to a pH between 3.4 and 4.0 with a single aliquot of standardized hydrochloric acid (~0.1 mol kg-1 HCl in ~0.6 mol kg-1 NaCl solution). The sample is then stirred for five minutes while air is bubbled into the sample at a rate of 200 scc/m to remove any liberated carbon dioxide gas. A Metrohm 876 Dosimat Plus is used for all standardized hydrochloric acid additions. After the five-minute period, the titration is continued until a pH of about 3.0 has been reached. The progress of the titration is monitored using a pH glass electrode/reference electrode cell, and the total alkalinity is computed from the titrant volume and e.m.f. measurements using a non-linear least-squares approach [Dickson2007]. An Agilent 34970A Data Acquisition/Switch Unit with a 34901A multiplexer is used to read the voltage measurements from the electrode and monitor the temperatures from the sample, acid, and room. The calculations for this procedure are performed automatically using LabVIEW 2012.; CRM manufacturer: Dickson laboratory Certified Reference Material (CRM); CRM batch number: Batch 172: 2217.40 ± 0.7 𝜇mol/kg; TA blank correction: N/A; Method reference: Dickson, Andrew G., Chris Sabine and James R. Christian, editors, "Guide to Best Practices for Ocean CO2 Measurements", Pices Special Publication 3, IOCCP Report No. 8, October 2007, SOP 3b, "Determination of total alkalinity in sea water using an open-cell titration"; Researcher name: Andrew Dickson; Researcher institution: SIO. Parameter or Variable: pH; Abbreviation: PH_TOT; pH scale: total hydrogen ion concentration scale (mol/kg-sw); Observation type: discrete; Measured or calculated: Measured; Sampling instrument: Niskin Bottles; Temperature of pH measurement: 25 °C; Detailed sampling and analyzing information: pH was measured spectrophotometrically on the total hydrogen scale using an Agilent 8453 spectrophotometer and in accordance with the methods outlined by Carter et al., 2013. [Carter2013]. A Kloehn V6 syringe pump was used to autonomously fill, mix, and dispense sample through the custom 10cm flow-through jacketed cell. A Thermo NESLAB RTE-7 recirculating water bath was used to maintain the cell temperature at 25.0°C during analyses, and a YSI 4600 precision thermometer and probe were used to monitor and record the temperature of each sample immediately after the spectrophotometric measurements were taken. The indicator meta-cresol purple (mCP) was used to measure the absorbance of light measured at two different wavelengths (434 nm, 578 nm) corresponding to the maximum absorbance peaks for the acidic and basic forms of the indicator dye. A baseline absorbance (Abase) was also measured and subtracted from these wavelengths. The baseline absorbance was determined by averaging the absorbances from 725-735nm. The ratio of the absorbances was then used to calculate pH on the total scale using the equations outlined in Liu et al., 2011 [Liu2011]. The salinity data used was obtained from the conductivity sensor on the CTD. The salinity data was later corroborated by shipboard measurements.; Researcher name: Andrew Dickson; Researcher institution: SIO. Parameter or Variable: PH_TMP; Abbreviation: PH_TMP; Unit: DEG_C; Controlled vocabulary name: pH; In-situ / Manipulation / Response variable: in-situ. Parameter or Variable: CTDTMP; Abbreviation: CTDTMP; Unit: DEG_C; Controlled vocabulary name: WATER TEMPERATURE; In-situ / Manipulation / Response variable: in-situ. Parameter or Variable: CTDSAL; Abbreviation: CTDSAL; Controlled vocabulary name: SALINITY; In-situ / Manipulation / Response variable: in-situ. Parameter or Variable: SALNTY; Abbreviation: SALNTY; Controlled vocabulary name: SALINITY; In-situ / Manipulation / Response variable: in-situ. Parameter or Variable: CTDOXY; Abbreviation: CTDOXY; Unit: UMOL/KG; Controlled vocabulary name: DISSOLVED OXYGEN; In-situ / Manipulation / Response variable: in-situ. Parameter or Variable: OXYGEN; Abbreviation: OXYGEN; Unit: UMOL/KG; Controlled vocabulary name: DISSOLVED OXYGEN; In-situ / Manipulation / Response variable: in-situ. Parameter or Variable: SILCAT; Abbreviation: SILCAT; Unit: UMOL/KG; Controlled vocabulary name: silicate; In-situ / Manipulation / Response variable: in-situ. Parameter or Variable: NITRAT; Abbreviation: NITRAT; Unit: UMOL/KG; Controlled vocabulary name: NITRATE; In-situ / Manipulation / Response variable: in-situ. Parameter or Variable: NITRIT; Abbreviation: NITRIT; Unit: UMOL/KG; Controlled vocabulary name: NITRITE; In-situ / Manipulation / Response variable: in-situ. Parameter or Variable: PHSPHT; Abbreviation: PHSPHT; Unit: UMOL/KG; Controlled vocabulary name: phosphate; In-situ / Manipulation / Response variable: in-situ. Parameter or Variable: CFC-11; Abbreviation: CFC-11; Unit: PMOL/KG; Controlled vocabulary name: CHLOROFLUOROCARBON-11 (CFC-11); In-situ / Manipulation / Response variable: in-situ. Parameter or Variable: CFC-12; Abbreviation: CFC-12; Unit: PMOL/KG; Controlled vocabulary name: CHLOROFLUOROCARBON-12 (CFC-12); In-situ / Manipulation / Response variable: in-situ. Parameter or Variable: SF6; Abbreviation: SF6; Unit: FMOL/KG; Controlled vocabulary name: Sulfur Hexaflouride (SF6); In-situ / Manipulation / Response variable: in-situ. Parameter or Variable: Dissolved Organic Carbon; Abbreviation: DOC; Unit: UMOL/KG; Observation type: Discrete; In-situ / Manipulation / Response variable: in-situ. Parameter or Variable: Total Dissolved Nitrogen; Abbreviation: TDN; Unit: UMOL/KG; Observation type: Discrete; In-situ / Manipulation / Response variable: in-situ. Parameter or Variable: Delta C14; Abbreviation: DELC14; Unit: /MILLE; Observation type: Discrete; In-situ / Manipulation / Response variable: in-situ. Parameter or Variable: Delta C14; Abbreviation: DELC14; Unit: /MILLE; Observation type: Discrete; In-situ / Manipulation / Response variable: in-situ. Parameter or Variable: Delta C13; Abbreviation: DELC13; Unit: /MILLE; Observation type: Discrete; In-situ / Manipulation / Response variable: in-situ. Parameter or Variable: CHLORA; Abbreviation: CHLORA; Unit: UG/KG; Observation type: Discrete; In-situ / Manipulation / Response variable: in-situ .

Lineage information for: dataset

Processing Steps

Parameter or Variable: Dissolved Inorganic Carbon; Abbreviation: TCARBN; Unit: UMOL/KG; Observation type: discrete; Measured or calculated: Measured; Sampling instrument: Niskin Bottles; Analyzing instrument: SOMMA; Detailed sampling and analyzing information: DIC analysis was performed via coulometry using two analytical systems (PMEL1 and PMEL2) simultaneously on the cruise. Each system consisted of a coulometer (CM5015-O UIC Inc) coupled with a Dissolved Inorganic Carbon Extractor (DICE). The DICE system 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). In coulometric analysis of DIC, all carbonate species are converted to CO2 (gas) by addition of excess hydrogen ion (acid) to the seawater sample, and the evolved CO2 gas is swept into the titration cell of the coulometer with pure air or compressed nitrogen, where it reacts quantitatively with a proprietary reagent based on ethanolamine to generate hydrogen ions. In this process, the solution changes from blue to colorless, triggering a current through the cell and causing coulometrical generation of OH- ions at the anode. The OH- ions react with the H+, and the solution turns blue again. A beam of light is shone through the solution, and a photometric detector at the opposite side of the cell senses the change in transmission. Once the percent transmission reaches its original value, the coulometric titration is stopped, and the amount of CO2 that enters the cell is determined by integrating the total change during the titration.; Replicate information: Duplicate samples from the same niskin were measured near the beginning; middle and end of each cell.; CRM batch number: 172: Certified Value = 2039.06 μmol/kg; Preservation method: 0.12 ml of saturated HgCl2 used for sample preservation; Uncertainty: The precision of the two DICE systems can be demonstrated via the replicate samples. Approximately 11.5% of the niskins sampled were duplicates taken as a check of our precision. These replicate samples were interspersed throughout the station analysis for quality assurance and integrity of the coulometer cell solutions. The average absolute difference from the mean of these replicates is 0.67 μmol/kg - no major systematic differences between the replicates were observed.; Method reference: Johnson et al. 1985, 1987, 1993, and 1999; Johnson 1992; Researcher name: Rik Wanninkhof, Richard Feely; Researcher institution: NOAA/AOML; NOAA/PMEL.
Parameter or Variable: Total alkalinity; Abbreviation: ALKALI; Unit: UMOL/KG; Observation type: discrete; Measured or calculated: Measured; Type of titration: two-stage open cell acidimetric, potentiometric; Cell type (open or closed): open cell titration; Detailed sampling and analyzing information: Seawater samples are analyzed using an open cell two-stage titration procedure using two 250 mL jacketed cells. One sample is undergoing titration while the second is being prepared and equilibrating to 20°C for analysis. The sample of seawater is first acidified to a pH between 3.4 and 4.0 with a single aliquot of standardized hydrochloric acid (~0.1 mol kg-1 HCl in ~0.6 mol kg-1 NaCl solution). The sample is then stirred for five minutes while air is bubbled into the sample at a rate of 200 scc/m to remove any liberated carbon dioxide gas. A Metrohm 876 Dosimat Plus is used for all standardized hydrochloric acid additions. After the five-minute period, the titration is continued until a pH of about 3.0 has been reached. The progress of the titration is monitored using a pH glass electrode/reference electrode cell, and the total alkalinity is computed from the titrant volume and e.m.f. measurements using a non-linear least-squares approach [Dickson2007]. An Agilent 34970A Data Acquisition/Switch Unit with a 34901A multiplexer is used to read the voltage measurements from the electrode and monitor the temperatures from the sample, acid, and room. The calculations for this procedure are performed automatically using LabVIEW 2012.; CRM manufacturer: Dickson laboratory Certified Reference Material (CRM); CRM batch number: Batch 172: 2217.40 ± 0.7 𝜇mol/kg; TA blank correction: N/A; Method reference: Dickson, Andrew G., Chris Sabine and James R. Christian, editors, "Guide to Best Practices for Ocean CO2 Measurements", Pices Special Publication 3, IOCCP Report No. 8, October 2007, SOP 3b, "Determination of total alkalinity in sea water using an open-cell titration"; Researcher name: Andrew Dickson; Researcher institution: SIO.
Parameter or Variable: pH; Abbreviation: PH_TOT; pH scale: total hydrogen ion concentration scale (mol/kg-sw); Observation type: discrete; Measured or calculated: Measured; Sampling instrument: Niskin Bottles; Temperature of pH measurement: 25 °C; Detailed sampling and analyzing information: pH was measured spectrophotometrically on the total hydrogen scale using an Agilent 8453 spectrophotometer and in accordance with the methods outlined by Carter et al., 2013. [Carter2013]. A Kloehn V6 syringe pump was used to autonomously fill, mix, and dispense sample through the custom 10cm flow-through jacketed cell. A Thermo NESLAB RTE-7 recirculating water bath was used to maintain the cell temperature at 25.0°C during analyses, and a YSI 4600 precision thermometer and probe were used to monitor and record the temperature of each sample immediately after the spectrophotometric measurements were taken. The indicator meta-cresol purple (mCP) was used to measure the absorbance of light measured at two different wavelengths (434 nm, 578 nm) corresponding to the maximum absorbance peaks for the acidic and basic forms of the indicator dye. A baseline absorbance (Abase) was also measured and subtracted from these wavelengths. The baseline absorbance was determined by averaging the absorbances from 725-735nm. The ratio of the absorbances was then used to calculate pH on the total scale using the equations outlined in Liu et al., 2011 [Liu2011]. The salinity data used was obtained from the conductivity sensor on the CTD. The salinity data was later corroborated by shipboard measurements.; Researcher name: Andrew Dickson; Researcher institution: SIO.
Parameter or Variable: PH_TMP; Abbreviation: PH_TMP; Unit: DEG_C; Controlled vocabulary name: pH; In-situ / Manipulation / Response variable: in-situ.
Parameter or Variable: CTDTMP; Abbreviation: CTDTMP; Unit: DEG_C; Controlled vocabulary name: WATER TEMPERATURE; In-situ / Manipulation / Response variable: in-situ.
Parameter or Variable: CTDSAL; Abbreviation: CTDSAL; Controlled vocabulary name: SALINITY; In-situ / Manipulation / Response variable: in-situ.
Parameter or Variable: SALNTY; Abbreviation: SALNTY; Controlled vocabulary name: SALINITY; In-situ / Manipulation / Response variable: in-situ.
Parameter or Variable: CTDOXY; Abbreviation: CTDOXY; Unit: UMOL/KG; Controlled vocabulary name: DISSOLVED OXYGEN; In-situ / Manipulation / Response variable: in-situ.
Parameter or Variable: OXYGEN; Abbreviation: OXYGEN; Unit: UMOL/KG; Controlled vocabulary name: DISSOLVED OXYGEN; In-situ / Manipulation / Response variable: in-situ.
Parameter or Variable: SILCAT; Abbreviation: SILCAT; Unit: UMOL/KG; Controlled vocabulary name: silicate; In-situ / Manipulation / Response variable: in-situ.
Parameter or Variable: NITRAT; Abbreviation: NITRAT; Unit: UMOL/KG; Controlled vocabulary name: NITRATE; In-situ / Manipulation / Response variable: in-situ.
Parameter or Variable: NITRIT; Abbreviation: NITRIT; Unit: UMOL/KG; Controlled vocabulary name: NITRITE; In-situ / Manipulation / Response variable: in-situ.
Parameter or Variable: PHSPHT; Abbreviation: PHSPHT; Unit: UMOL/KG; Controlled vocabulary name: phosphate; In-situ / Manipulation / Response variable: in-situ.
Parameter or Variable: CFC-11; Abbreviation: CFC-11; Unit: PMOL/KG; Controlled vocabulary name: CHLOROFLUOROCARBON-11 (CFC-11); In-situ / Manipulation / Response variable: in-situ.
Parameter or Variable: CFC-12; Abbreviation: CFC-12; Unit: PMOL/KG; Controlled vocabulary name: CHLOROFLUOROCARBON-12 (CFC-12); In-situ / Manipulation / Response variable: in-situ.
Parameter or Variable: SF6; Abbreviation: SF6; Unit: FMOL/KG; Controlled vocabulary name: Sulfur Hexaflouride (SF6); In-situ / Manipulation / Response variable: in-situ.
Parameter or Variable: Dissolved Organic Carbon; Abbreviation: DOC; Unit: UMOL/KG; Observation type: Discrete; In-situ / Manipulation / Response variable: in-situ.
Parameter or Variable: Total Dissolved Nitrogen; Abbreviation: TDN; Unit: UMOL/KG; Observation type: Discrete; In-situ / Manipulation / Response variable: in-situ.
Parameter or Variable: Delta C14; Abbreviation: DELC14; Unit: /MILLE; Observation type: Discrete; In-situ / Manipulation / Response variable: in-situ.
Parameter or Variable: Delta C14; Abbreviation: DELC14; Unit: /MILLE; Observation type: Discrete; In-situ / Manipulation / Response variable: in-situ.
Parameter or Variable: Delta C13; Abbreviation: DELC13; Unit: /MILLE; Observation type: Discrete; In-situ / Manipulation / Response variable: in-situ.
Parameter or Variable: CHLORA; Abbreviation: CHLORA; Unit: UG/KG; Observation type: Discrete; In-situ / Manipulation / Response variable: in-situ .

Acquisition Information (collection)
Instrument	carbon dioxide (CO2) gas analyzer CTD Niskin bottle pH sensor salinometer temperature probe titrator
Platform	RV Nathaniel B. Palmer

Last Modified: 2024-06-10T13:16:30Z
For questions about the information on this page, please email: ncei.info@noaa.gov

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