| Contributors | Affiliation | Role |
|---|---|---|
| Sedwick, Peter N. | Old Dominion University (ODU) | Principal Investigator |
| Anderson, Robert F. | Lamont-Doherty Earth Observatory (LDEO) | Co-Principal Investigator |
| Lam, Phoebe J. | University of California-Santa Cruz (UCSC) | Co-Principal Investigator |
| Sherrell, Robert M. | Rutgers University | Co-Principal Investigator |
Water column samples were collected using seven different sampling systems, each of which is detailed below. Wherever feasible, methods adhered to protocols described in the GEOTRACES Cookbook (Aguilar-Islas et al., 2024)
(1) Conventional CTD rosette ("ODF rosette") system deployments. The ODF rosette casts were performed with a package consisting of a 36-bottle rosette frame, a 36-place carousel and 36 x 10.6 liter (L) Bullister-style Niskin sampler bottles. The carousel was provided by the NOAA PMEL, with primary underwater electronic components consisting of a SeaBird Electronics housing unit with a pressure sensor, temperature sensors, conductivity sensors, and a membrane oxygen sensor, as well as a transmissometer, chlorophyll-a fluorometer, altimeter, and turbidity sensor. The package was deployed on a conducting steel hydrowire using the winch in the Baltic Room of RVIB Nathaniel B. Palmer. Further details are provided in the Instruments section and the ODF cruise report (Scripps Institution of Oceanography Ocean Data Facility team, 2024).
(2) Trace-metal clean CTD rosette ("GTC rosette") system deployments. The GTC rosette casts were performed using the U.S. GEOTRACES trace-element rosette sampling system with a SeaBird custom-built frame and carousel (newly purchased) and 24 x 12 L GoFlo sampler bottles. The system included a SeaBird Electronics CTD unit with a pressure sensor, temperature sensors, conductivity sensors, and a membrane oxygen sensor, as well as a transmissometer, chlorophyll-a fluorometer, altimeter, and turbidity sensor. The package was deployed on sheathed conducting cable with Vectran strength member using a Dynacon winch mounted on the 02 deck of RVIB Nathaniel B. Palmer. Further details are provided in the Instruments section and the GP17-ANT cruise report (Sedwick et al., 2024).
(3) McLane in-situ pump deployments. During deep casts of the McLane in-situ pumps, which were deployed on Hytrel-coated, non-conducting Vectran line using a MASH4k winch mounted on the 02 deck of RVIB Nathaniel B. Palmer, 30 L Niskin samplers were attached to the Vectran line ~1-2 meters above each McLane pump, and were closed using Teflon-coated messengers. Sample depths are estimated using data collected by a SeaBird Electronics 19-plus v2 Seacat self-recording CTD that was shackled to the end of the Vectran wire for each pump cast. Further details are provided in the GP17-ANT cruise report (Sedwick et al., 2024).
(4) Multicorer deployments. During sediment collections using a Bowers and Connelly Mega Corer ("multicorer"), an external-closure Niskin-type sampler modified and cleaned for trace metal use was attached to the multicorer frame in a position ~1 meter above the seafloor, and was closed by means of a cable released upon initial descent of the multicorer tubes and associated weights. Sample depths are estimated from seafloor depths as indicated by the shipboard multibeam sonar system. The Niskin sampler closed successfully and returned samples for 8 of the 9 multicorer deployments, at Stations 7, 10, 14, 15, 17, 21, 25, and 27. Further details are provided in the GP17-ANT cruise report (Sedwick et al., 2024).
(5) Towfish deployments. Near-surface (~2 meters depth) seawater was collected while underway on approach to or departure from each station using an overboard towed-fish ("towfish") sampling system deployed outside of the ship's wake. Using a deckboard pneumatic Teflon diaphragm pump, seawater from the towfish was pumped into a shipboard clean-air laboratory van. Further details are provided in the GP17-ANT cruise report (Sedwick et al., 2024).
(6) Radium surface pump deployments. Near-surface (~3 meters depth) seawater samples for analysis of radium isotopes were collected using a surface pump deployed by hand over the starboard quarter of RVIB Nathaniel B. Palmer.
(7) Beryllium-7 pump deployments. Upper water-column (<200 meters depth) seawater samples for analysis of beryllium-7 were collected using a deckboard pump system and overboard weighted inlet tube. Sample depths are estimated from an in-situ logging pressure sensor.
Dissolved nutrients (nitrate+nitrite, nitrite, phosphate and silicate) were determined shipboard in unfiltered seawater samples using a Seal Analytical continuous-flow AutoAnalyzer 3 following methods described in the nutrient section of the updated GO-SHIP repeat hydrography manual (Becker et al., 2019; 2020). Accuracy and precision were assessed from the analysis of Reference Materials for Nutrients in Seawater (RMNS) batch CM at every station, which yielded concentrations ± one standard deviation of 33.12 ± 0.18 micromoles per kilogram (µmol/kg) nitrate, 2.39 ± 0.02 µmol/kg phosphate, 100.8 ± 1.0 µmol/kg silicate, and 0.025 ± 0.005 µmol/kg nitrite, versus RMNS assigned concentrations of 33.2 µmol/kg, 2.28 µmol/kg, 100.5 µmol/kg and 0.02 µmol/kg, respectively. Further methodological details are provided in the ODF cruise report (Scripps Institution of Oceanography Ocean Data Facility team, 2024).
Salinity was measured in discrete samples using the Guildline 8410A "Portasal" salinometer aboard RVIB Nathaniel B. Palmer. The salinometer was standardized for each group of samples analyzed (normally 2 to 6 casts, up to ~95 samples) using two bottles of standard seawater: one at the beginning and one at the end of each set of measurements. IAPSO Standard Seawater Batch P-167 was used for all calibrations: K15 = 0.99988, salinity 34.994, expiration 2026-02-21. PSS-78 salinity was calculated for each sample from the measured conductivity ratios. The offset between the initial standard seawater value and its reference value was applied to each sample. Then the difference (if any) between the initial and final vials of standard seawater was applied to each sample as a function of elapsed run time. Further methodological details are provided in the ODF cruise report (Scripps Institution of Oceanography Ocean Data Facility team, 2024).
Dissolved oxygen was measured in discrete samples using an SIO/ODF-designed automated oxygen titrator using photometric end-point detection based on the absorption of 365-nanometer (nm) wavelength ultraviolet light using a whole-bottle modified-Winkler titration following the technique of Carpenter (1965) with modifications by Culberson (1991), but with higher concentrations of potassium iodate standard (~0.012 N), and thiosulfate solution (~55 grams per liter (g/L)). Further methodological details are provided in the ODF cruise report (Scripps Institution of Oceanography Ocean Data Facility team, 2024).
Instrumentation Details:
ODF CTD rosette system and sensors: ODF rosette casts were performed with a package consisting of a 36-bottle rosette frame and carousel, and 36 (plus spares) x 10.6 L Bullister-style Niskin bottles. Underwater electronic components primarily consisted of an SBE-9plus housing unit with Digiquartz pressure sensor with dual plumbed lines where each line has a pump, SBE-3plus temperature sensor, SBE-4C conductivity sensor, and exhaust line. An SBE-43 membrane oxygen sensor was mounted on the "primary" line. An SBE-35 reference thermometer, JFE-Advantech RINKO oxygen optode, WetLabs C-Star transmissometer and ECO-FL-RTD chlorophyll-a fluorometer, Valeport VA500 altimeter, and SeaPoint turbidity sensor were also mounted on the rosette. The CTD pressure, temperature, conductivity, and oxygen sensors were calibrated prior to the cruise, whereas the transmissometer was calibrated before the start and after the end of science operations. The CTD data acquisition system consisted of an SBE-11plus (V1) deck unit and a networked generic PC workstation running Windows 10. SBE SeaSave7 v.7.26.7.121 software was used for data acquisition and to close bottles on the rosette. Further details are provided in the ODF cruise report (Scripps Institution of Oceanography Ocean Data Facility team, 2024).
GTC CTD rosette system and sensors: GTC rosette casts were performed with a package consisting of the 24-bottle U.S. GEOTRACES SBE trace-element rosette frame and carousel, and 24 (plus spares) x 12 L GoFlo sampler bottles. Underwater electronic components primarily consisted of an SBE 9plus housing unit with a Digiquartz pressure sensor, dual SeaBird SBE-3 temperature sensors and SBE-4C conductivity sensors, an SBE-43 membrane dissolved oxygen sensor, and a WetLabs C-Star transmissometer and ECO-FL-RTD chlorophyll-a fluorometer. Sensors were calibrated during summer 2023, immediately prior to the GP17-ANT cruise, and the transmissometer was calibrated before the start and after the end of science operations. The GTC rosette also included a Benthos altimeter, which ceased functioning during the latter part of the cruise and was replaced with a Valeport altimeter borrowed from the shipboard USAP equipment, and a Seapoint turbidity sensor. The CTD data acquisition system consisted of an SBE-11plus deck unit and a networked generic PC workstation running Windows 10. SBE SeaSave7 v.7.26.7.121 software was used for data acquisition and to close bottles on the rosette. Further details are provided in the GP17-ANT cruise report (Sedwick et al., 2024).
CTD used with McLane in-situ pump deployments: Niskin sampling depths were estimated from data recorded by an SBE 19-plus v2 Seacat self-recording CTD. Further details are provided in the GP17-ANT cruise report (Sedwick et al., 2024).
Dissolved nutrient analysis: Seal Analytical continuous-flow AutoAnalyzer 3. Further details are provided in the ODF cruise report (Scripps Institution of Oceanography Ocean Data Facility team, 2024).
Salinity measurements: Guildline 8410A Portasal salinometer. Further details are provided in the ODF cruise report (Scripps Institution of Oceanography Ocean Data Facility team, 2024).
Dissolved oxygen analyses: SIO-ODF-designed automated oxygen titrator using photometric end-point detection based on the absorption of 365 nm wavelength ultra-violet light. Sample titration and data logging were controlled by PC LabView software. Thiosulfate was dispensed by a Dosimat 665 buret driver fitted with a 1.0 ml burette. Further details are provided in the ODF cruise report (Scripps Institution of Oceanography Ocean Data Facility team, 2024).
CTD data from ODF and GTC rosettes: Shipboard CTD data processing was performed after deployment using SIO/ODF CTD processing software ctdcal v. 0.1.4b. CTD acquisition data were copied onto a Macintosh OS X system, and then processed. CTD data at bottle trips were extracted, and a 2-decibar downcast pressure series created. The pressure series data set was submitted for CTD data distribution after corrections were applied. CTD data were examined at the completion of each deployment for clean corrected sensor response and any calibration shifts. As bottle salinity and oxygen results became available, they were used to refine conductivity and oxygen sensor calibrations. Temperature, salinity, and dissolved oxygen comparisons were made between down and upcasts, as well as between groups of adjacent deployments. Further details are provided in the ODF cruise report (Scripps Institution of Oceanography Ocean Data Facility team, 2024).
Nutrient analyses: Data collection and processing were done with the software provided with the instrument from Seal Analytical (AACE). After each run, the charts were reviewed for any problems during the run, any blank was subtracted, and final concentrations (in micromoles per liter (µmol/L)) were calculated, based on a linear curve fit. Once the run was reviewed and concentrations calculated, a text file was created. That text file was reviewed then converted to another text file with only sample identifiers and nutrient concentrations, then merged with other bottle data.
Salinity measurements: Communications with the Portasal were established using a Windows 10 workstation running Salinometer Data Logger v1.2 by Ocean Scientific International. PSS-78 salinity was calculated for each sample from the measured conductivity ratios. The offset between the initial standard seawater value and its reference value was applied to each sample, then the difference (if any) between initial and final analyses of standard seawater was applied to each sample as a function of elapsed run time. The corrected salinity data were then incorporated into the cruise database.
Dissolved oxygen analyses: Sample draw temperatures, measured with an electronic resistance temperature detector embedded in the draw tube, were used to calculate concentrations in µmol/kg, and as a diagnostic check of bottle integrity. Samples were analyzed within 2-24 hours of collection, and the data incorporated into the cruise database. Thiosulfate normalities were calculated for each standardization and corrected to 20 degrees Celsius (°C). The 20°C thiosulfate normalities and blanks were plotted versus time and reviewed for possible problems, and subsequently determined to be stable enough that no smoothing was required.
This section documents curation actions performed prior to publication review with the submitter, and additional information relevant to understanding and reusing this dataset. It distinguishes changes made to the submitted (meta)data from unresolved issues and/or enhancements that improve future reuse and interoperability.
CURATION ACTIONS PERFORMED ON DATA
- Imported original file "Sedwick_GP17-ANT_Bottle_Data_BCO-DMO_07-30-26.xlsx" (sheet 1) into the BCO-DMO data processing system.
- Treated row 12 as header, skipped row 13 (units row).
- Treated "ND" as a missing data value, meaning it was removed. (Missing data are empty/blank in the final CSV file published by BCO-DMO).
- Deleted "Column title" column (empty).
- Renamed columns to comply with BCO-DMO naming conventions.
- Converted Start_Date_UTC (%d/%m/%Y) and Start_Time_UTC (%H:%M:%S) into a combined Start_ISO_DateTime_UTC datetime column (UTC, output format %Y-%m-%dT%H:%M:%SZ).
- Converted End_Date_UTC and End_Time_UTC into a combined End_ISO_DateTime_UTC datetime column (UTC, output format %Y-%m-%dT%H:%M:%SZ).
- Reordered columns.
- Converted Start_Date_UTC and End_Date_UTC into format %Y-%m-%d.
- Saved the final file as "1009991_v1_gp17-ant_bottle_data.csv".
CURATION ACTIONS PERFORMED ON METADATA
- BCO-DMO's standard metadata entry and text formatting steps were performed. See: https://www.bco-dmo.org/how-to/standard-curation-edits
ISSUES POTENTIALLY IMPACTING REUSE
- N/A
| Parameter | Description | Units |
| Station_ID | cruise station identifier | unitless |
| Event_ID | unique identifier for each sampling operation | unitless |
| Gear_ID | sampling device identifier: GF-# = GoFlo bottle #; GSNIS-# = Niskin bottle #; MCLANE-NIS-# = pump cast Niskin bottle #; FISH = towfish underway sampling; BE-PUMP = Beryllium-7 pump sampling; RA-PUMP = Radium pump sampling; MULTICORER = Niskin bottle on multicorer | unitless |
| Gear_ID_flag | sample quality flag (see Problems/Issues for quality flag definitions) | unitless |
| Start_ISO_DateTime_UTC | start date and time (UTC) of sampling operation in ISO 8601 format; Note: For all McLane pump casts, the reported start and end times/dates designate start/end times/dates for actual pumping, not start/end for the entire cast. | unitless |
| Start_Date_UTC | start date of sampling operation (UTC) | unitless |
| Start_Time_UTC | start time of sampling operation (UTC) | unitless |
| End_ISO_DateTime_UTC | end date and time (UTC) of sampling operation in ISO 8601 format; Note: For all McLane pump casts, the reported start and end times/dates designate start/end times/dates for actual pumping, not start/end for the entire cast. | unitless |
| End_Date_UTC | end date of sampling operation (UTC) | unitless |
| End_Time_UTC | end time of sampling operation (UTC) | unitless |
| Start_Latitude | start latitude of sampling operation (negative value = South) | decimal degrees N |
| Start_Longitude | start longitude of sampling operation (negative value = West) | decimal degrees E |
| End_Latitude | end latitude of sampling operation (negative value = South) | decimal degrees N |
| End_Longitude | end longitude of sampling operation (negative value = West) | decimal degrees E |
| Sample_ID | GEOTRACES sample number = unique identifier for each water-column sample | unitless |
| Sample_Depth | water depth of sample (below sea surface) | meters |
| CTDPRS_UP_T_VALUE_SENSOR_ydynbi | sensor pressure from upcast (the 6 trailing letters are GEOTRACES barcode) | decibar |
| SD1_CTDPRS_UP_T_VALUE_SENSOR_ydynbi | standard deviation on sensor pressure from upcast (the 6 trailing letters are GEOTRACES barcode) | decibar |
| Flag_CTDPRS_UP_T_VALUE_SENSOR_ydynbi | data quality flag (see Problems/Issues for quality flag definitions) for CTDPRS_UP_T_VALUE_SENSOR (the 6 trailing letters are GEOTRACES barcode) | unitless |
| NITRATE_D_CONC_BOTTLE_owiemd | nitrate concentration of bottle sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| SD1_NITRATE_D_CONC_BOTTLE_owiemd | standard deviation on nitrate concentration of bottle sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| Flag_NITRATE_D_CONC_BOTTLE_owiemd | data quality flag (see Problems/Issues for quality flag definitions) for NITRATE_D_CONC_BOTTLE (the 6 trailing letters are GEOTRACES barcode) | unitless |
| NITRATE_D_CONC_FISH_pt2a4c | nitrate concentration of towfish sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| SD1_NITRATE_D_CONC_FISH_pt2a4c | standard deviation on nitrate concentration of towfish sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| Flag_NITRATE_D_CONC_FISH_pt2a4c | data quality flag (see Problems/Issues for quality flag definitions) for NITRATE_D_CONC_FISH (the 6 trailing letters are GEOTRACES barcode) | unitless |
| NITRATE_D_CONC_PUMP_pepwzi | nitrate concentration of pumped sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| SD1_NITRATE_D_CONC_PUMP_pepwzi | standard deviation on nitrate concentration of pumped sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| Flag_NITRATE_D_CONC_PUMP_pepwzi | data quality flag (see Problems/Issues for quality flag definitions) for NITRATE_D_CONC_PUMP (the 6 trailing letters are GEOTRACES barcode) | none |
| NITRITE_D_CONC_BOTTLE_xdrz0y | nitrite concentration of bottle sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| SD1_NITRITE_D_CONC_BOTTLE_xdrz0y | standard deviation on nitrite concentration of bottle sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| Flag_NITRITE_D_CONC_BOTTLE_xdrz0y | data quality flag (see Problems/Issues for quality flag definitions) for NITRITE_D_CONC_BOTTLE (the 6 trailing letters are GEOTRACES barcode) | unitless |
| NITRITE_D_CONC_FISH_pu8yik | nitrite concentration of towfish sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| SD1_NITRITE_D_CONC_FISH_pu8yik | standard deviation on nitrite concentration of towfish sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| Flag_NITRITE_D_CONC_FISH_pu8yik | data quality flag (see Problems/Issues for quality flag definitions) for NITRITE_D_CONC_FISH (the 6 trailing letters are GEOTRACES barcode) | unitless |
| NITRITE_D_CONC_PUMP_zt8gpj | nitrite concentration of pumped sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| SD1_NITRITE_D_CONC_PUMP_zt8gpj | standard deviation on nitrite concentration of pumped sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| Flag_NITRITE_D_CONC_PUMP_zt8gpj | data quality flag (see Problems/Issues for quality flag definitions) for NITRITE_D_CONC_PUMP (the 6 trailing letters are GEOTRACES barcode) | unitless |
| PHOSPHATE_D_CONC_BOTTLE_9fzvdv | phosphate concentration of bottle sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| SD1_PHOSPHATE_D_CONC_BOTTLE_9fzvdv | standard deviation on phosphate concentration of bottle sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| Flag_PHOSPHATE_D_CONC_BOTTLE_9fzvdv | data quality flag (see Problems/Issues for quality flag definitions) for PHOSPHATE_D_CONC_BOTTLE (the 6 trailing letters are GEOTRACES barcode) | unitless |
| PHOSPHATE_D_CONC_FISH_y8qlge | phosphate concentration of towfish sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| SD1_PHOSPHATE_D_CONC_FISH_y8qlge | standard deviation on phosphate concentration of towfish sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| Flag_PHOSPHATE_D_CONC_FISH_y8qlge | data quality flag (see Problems/Issues for quality flag definitions) for PHOSPHATE_D_CONC_FISH (the 6 trailing letters are GEOTRACES barcode) | unitless |
| PHOSPHATE_D_CONC_PUMP_4yxu4v | phosphate concentration of pumped sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| SD1_PHOSPHATE_D_CONC_PUMP_4yxu4v | standard deviation on phosphate concentration of pumped sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| Flag_PHOSPHATE_D_CONC_PUMP_4yxu4v | data quality flag (see Problems/Issues for quality flag definitions) for PHOSPHATE_D_CONC_PUMP (the 6 trailing letters are GEOTRACES barcode) | unitless |
| SILICATE_D_CONC_BOTTLE_cqslad | silicate concentration of bottle sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| SD1_SILICATE_D_CONC_BOTTLE_cqslad | standard deviation on silicate concentration of bottle sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| Flag_SILICATE_D_CONC_BOTTLE_cqslad | data quality flag (see Problems/Issues for quality flag definitions) for SILICATE_D_CONC_BOTTLE (the 6 trailing letters are GEOTRACES barcode) | unitless |
| SILICATE_D_CONC_FISH_7bxhe0 | silicate concentration of towfish sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| SD1_SILICATE_D_CONC_FISH_7bxhe0 | standard deviation on silicate concentration of towfish sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| Flag_SILICATE_D_CONC_FISH_7bxhe0 | data quality flag (see Problems/Issues for quality flag definitions) for SILICATE_D_CONC_FISH (the 6 trailing letters are GEOTRACES barcode) | unitless |
| SILICATE_D_CONC_PUMP_llsgvx | silicate concentration of pumped sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| SD1_SILICATE_D_CONC_PUMP_llsgvx | standard deviation on silicate concentration of pumped sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| Flag_SILICATE_D_CONC_PUMP_llsgvx | data quality flag (see Problems/Issues for quality flag definitions) for SILICATE_D_CONC_PUMP (the 6 trailing letters are GEOTRACES barcode) | unitless |
| CTDTMP_UP_T_VALUE_SENSOR_wbop31 | sensor temperature from upcast (the 6 trailing letters are GEOTRACES barcode) | degrees Celsius |
| SD1_CTDTMP_UP_T_VALUE_SENSOR_wbop31 | standard deviation on sensor temperature from upcast (the 6 trailing letters are GEOTRACES barcode) | degrees Celsius |
| Flag_CTDTMP_UP_T_VALUE_SENSOR_wbop31 | data quality flag (see Problems/Issues for quality flag definitions) for CTDTMP_UP_T_VALUE_SENSOR (the 6 trailing letters are GEOTRACES barcode) | unitless |
| CTDSAL_UP_D_CONC_SENSOR_qsismz | sensor salinity from upcast (the 6 trailing letters are GEOTRACES barcode) | unitless |
| SD1_CTDSAL_UP_D_CONC_SENSOR_qsismz | standard deviation on sensor salinity from upcast (the 6 trailing letters are GEOTRACES barcode) | unitless |
| Flag_CTDSAL_UP_D_CONC_SENSOR_qsismz | data quality flag (see Problems/Issues for quality flag definitions) for CTDSAL_UP_D_CONC_SENSOR (the 6 trailing letters are GEOTRACES barcode) | unitless |
| SALINITY_D_CONC_BOTTLE_7pchb6 | salinity of bottle sample (the 6 trailing letters are GEOTRACES barcode) | unitless |
| SD1_SALINITY_D_CONC_BOTTLE_7pchb6 | standard deviation on salinity of bottle sample (the 6 trailing letters are GEOTRACES barcode) | unitless |
| Flag_SALINITY_D_CONC_BOTTLE_7pchb6 | data quality flag (see Problems/Issues for quality flag definitions) for SALINITY_D_CONC_BOTTLE (the 6 trailing letters are GEOTRACES barcode) | unitless |
| SALINITY_D_CONC_FISH_4vkmjo | salinity of towfish sample (the 6 trailing letters are GEOTRACES barcode) | unitless |
| SD1_SALINITY_D_CONC_FISH_4vkmjo | standard deviation on salinity of towfish sample (the 6 trailing letters are GEOTRACES barcode) | unitless |
| Flag_SALINITY_D_CONC_FISH_4vkmjo | data quality flag (see Problems/Issues for quality flag definitions) for SALINITY_D_CONC_FISH (the 6 trailing letters are GEOTRACES barcode) | unitless |
| SALINITY_D_CONC_PUMP_pjrgvj | salinity of pumped sample (the 6 trailing letters are GEOTRACES barcode) | unitless |
| SD1_SALINITY_D_CONC_PUMP_pjrgvj | standard deviation on salinity of pumped sample (the 6 trailing letters are GEOTRACES barcode) | unitless |
| Flag_SALINITY_D_CONC_PUMP_pjrgvj | data quality flag (see Problems/Issues for quality flag definitions) for SALINITY_D_CONC_PUMP (the 6 trailing letters are GEOTRACES barcode) | unitless |
| CTDOXY_UP_D_CONC_SENSOR_2spkfk | sensor dissolved oxygen concentration from upcast (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| SD1_CTDOXY_UP_D_CONC_SENSOR_2spkfk | standard deviation on sensor dissolved oxygen concentration from upcast (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| Flag_CTDOXY_UP_D_CONC_SENSOR_2spkfk | data quality flag (see Problems/Issues for quality flag definitions) for CTDOXY_UP_D_VALUE_SENSOR (the 6 trailing letters are GEOTRACES barcode) | unitless |
| OXYGEN_D_CONC_BOTTLE_luceph | dissolved oxygen concentration of bottle sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| SD1_OXYGEN_D_CONC_BOTTLE_luceph | standard deviation on dissolved oxygen concentration of bottle sample (the 6 trailing letters are GEOTRACES barcode) | micromoles per kilogram |
| Flag_OXYGEN_D_CONC_BOTTLE_luceph | data quality flag (see Problems/Issues for quality flag definitions) for OXYGEN_D_CONC_BOTTLE (the 6 trailing letters are GEOTRACES barcode) | unitless |
| CTDTURB_UP_RAW_T_VALUE_SENSOR_if7loo | sensor turbidity (raw uncalibrated data) from upcast (the 6 trailing letters are GEOTRACES barcode) | volts |
| SD1_CTDTURB_UP_RAW_T_VALUE_SENSOR_if7loo | standard deviation on sensor turbidity (raw uncalibrated data) from upcast (the 6 trailing letters are GEOTRACES barcode) | volts |
| Flag_CTDTURB_UP_RAW_T_VALUE_SENSOR_if7loo | data quality flag (see Problems/Issues for quality flag definitions) for CTDTURB_UP_RAW_T_VALUE_SENSOR (the 6 trailing letters are GEOTRACES barcode) | unitless |
| CTDXMISS_UP_RAW_T_VALUE_SENSOR_uolrwg | sensor beam transmission (raw uncalibrated data) from upcast (the 6 trailing letters are GEOTRACES barcode) | volts |
| SD1_CTDXMISS_UP_RAW_T_VALUE_SENSOR_uolrwg | standard deviation on sensor beam transmission (raw uncalibrated data) from upcast (the 6 trailing letters are GEOTRACES barcode) | volts |
| Flag_CTDXMISS_UP_RAW_T_VALUE_SENSOR_uolrwg | data quality flag (see Problems/Issues for quality flag definitions) for CTDXMISS_UP_RAW_T_VALUE_SENSOR (the 6 trailing letters are GEOTRACES barcode) | unitless |
| CTDFLUOR_UP_RAW_T_VALUE_SENSOR_1bhbv8 | sensor chlorophyll-a fluorescence (raw uncalibrated data) from upcast (the 6 trailing letters are GEOTRACES barcode) | volts |
| SD1_CTDFLUOR_UP_RAW_T_VALUE_SENSOR_1bhbv8 | standard deviation on sensor chlorophyll-a fluorescence (raw uncalibrated data) from upcast (the 6 trailing letters are GEOTRACES barcode) | volts |
| Flag_CTDFLUOR_UP_RAW_T_VALUE_SENSOR_1bhbv8 | data quality flag (see Problems/Issues for quality flag definitions) for CTDFLUOR_UP_RAW_T_VALUE_SENSOR (the 6 trailing letters are GEOTRACES barcode) | unitless |
| Dataset-specific Instrument Name | Seal Analytical continuous-flow AutoAnalyzer 3 |
| Generic Instrument Name | Bran+Luebbe / SEAL Analytical AutoAnalyzer 3 (AA3) continuous-flow analyzer |
| Dataset-specific Description | Dissolved nutrients (nitrate+nitrite, nitrite, phosphate and silicate) were determined shipboard in unfiltered seawater samples using a Seal Analytical continuous-flow AutoAnalyzer 3. See "Methods & Sampling" and the cruise reports for complete descriptions of this instrument. |
| Generic Instrument Description | The AutoAnalyzer 3 (AA3) is a segmented continuous-flow analyzer (continuous flow analyzer, CFA) used for automated colorimetric analysis of dissolved nutrients and other analytes in environmental, seawater, freshwater, wastewater, soil, and agricultural samples. The AA3 was originally manufactured by Bran+Luebbe and, following acquisition of the product line in 2006, has continued to be manufactured and supported by SEAL Analytical. The AA3 is the third-generation instrument in the Technicon AutoAnalyzer family and is widely used for determination of nitrate, nitrite, ammonium, phosphate, silicate, and other dissolved nutrients. See the description from the manufacturer. |
| Dataset-specific Instrument Name | Towfish |
| Generic Instrument Name | GeoFish-type Near-surface Towfish Sampler |
| Dataset-specific Description | Near-surface (~2 meters depth) seawater was collected while underway on approach to or departure from each station using an overboard towed-fish ("towfish") sampling system deployed outside of the ship’s wake. The towfish system employed was loaned by Jessica Fitzsimmons (Texas A&M), and was a scaled-up version of a previous design employed by Co-Chief Sherrell, modified in minor ways from that used on GP17-OCE to better fit the specifics of deployment using the ship's starboard A-frame. See "Methods & Sampling" and the cruise reports for complete descriptions of this instrument. |
| Generic Instrument Description | This term describes a family of custom-designed, trace-metal-clean, near-surface seawater sampling systems based on the 'GeoFish' design developed by Geoffrey Smith and Ken Bruland at the University of California, Santa Cruz (UCSC). The systems consist of a weighted towed body or torpedo, clean intake tubing, a shipboard pneumatic pump, and a sampling manifold. They are deployed alongside a moving vessel, outside the ship's wake, with the intake typically positioned approximately 1 to 3 meters below the sea surface. Seawater is continuously pumped through the clean tubing to the ship for filtered and unfiltered sampling and, in some applications, direct connection to analytical instruments.
This term includes the original GeoFish sampler, Super-GeoFISH variants, and subsequent modified towfish systems used on U.S. GEOTRACES cruises. These systems share the same basic sampling principle but may differ in body construction, depressor or stabilization design, deployment hardware, tubing, pump configuration, flow rate, and sampling manifold. The systems have been used for trace-metal, nutrient, biological, and other chemical measurements in both GEOTRACES and non-GEOTRACES studies, including Bruland et al. (2005). |
| Dataset-specific Instrument Name | GoFlo sampler bottles |
| Generic Instrument Name | GO-FLO Bottle |
| Dataset-specific Description | The GTC rosette casts were performed using the U.S. GEOTRACES trace-element rosette sampling system with a SeaBird custom-built frame and carousel (newly purchased) and 24 x 12 L GoFlo sampler bottles. |
| Generic Instrument Description | GO-FLO bottle cast used to collect water samples for pigment, nutrient, plankton, etc. The GO-FLO sampling bottle is specially designed to avoid sample contamination at the surface, internal spring contamination, loss of sample on deck (internal seals), and exchange of water from different depths. |
| Dataset-specific Instrument Name | Guildline 8410A "Portasal" salinometer |
| Generic Instrument Name | Guildline Portasal 8410 series salinometer |
| Dataset-specific Description | Salinity was measured in discrete samples using the Guildline 8410A "Portasal" salinometer aboard RVIB Nathaniel B. Palmer. See "Methods & Sampling" and the cruise reports for complete descriptions of this instrument. |
| Generic Instrument Description | The Guildline Portasal 8410 series salinometer is a portable instrument for laboratory or field use that determines salinity of a water sample by comparison of its electrical conductivity with a standard solution. The system employs a continuous flow system, where the sample is drawn into the unit under low air pressure. A high stability temperature control bath and heat exchanger maintain the sample at a precisely defined, user selected temperature during analysis. The instrument can operate over a conductivity range of 0.004 to 76 mS/cm with a resolution of 0.0003 mS/cm (15 deg C and 35 PSU) or 0.0003 Equivalent PSU, and an accuracy of ± 0.003 Equivalent PSU (same set point temperature as standardization and within -2 deg C and +4 deg C of ambient).
The series consists of 2 known models: 8410 and 8410A. The models have the same specifications although the 8410A has an RS232 interface. The reference number 8410N refers to an operational manual update only. |
| Dataset-specific Instrument Name | McLane in-situ pumps |
| Generic Instrument Name | McLane Large Volume Pumping System WTS-LV |
| Dataset-specific Description | The WHOI UNOLS pump pool provided 8 dual-flow, battery-operated McLane pumps (5 WTS-LVDF, 3 modified WTS-LV-upright). Daniel Ohnemus provided 4 additional WTS-LVDF pumps. See "Methods & Sampling" and the cruise reports for complete descriptions of these instruments and associated sensors. |
| Generic Instrument Description | The WTS-LV is a Water Transfer System (WTS) Large Volume (LV) pumping instrument designed and manufactured by McLane Research Labs (Falmouth, MA, USA). It is a large-volume, single-event sampler that collects suspended and dissolved particulate samples in situ.
Ambient water is drawn through a modular filter holder onto a 142-millimeter (mm) membrane without passing through the pump. The standard two-tier filter holder provides prefiltering and size fractioning. Collection targets include chlorophyll maximum, particulate trace metals, and phytoplankton. It features different flow rates and filter porosity to support a range of specimen collection. Sampling can be programmed to start at a scheduled time or begin with a countdown delay. It also features a dynamic pump speed algorithm that adjusts flow to protect the sample as material accumulates on the filter. Several pump options range from 0.5 to 30 liters per minute, with a max volume of 2,500 to 36,000 liters depending on the pump and battery pack used. The standard model is depth rated to 5,500 meters, with a deeper 7,000-meter option available. The operating temperature is -4 to 35 degrees Celsius.
The WTS-LV is available in four different configurations: Standard, Upright, Bore Hole, and Dual Filter Sampler. The high-capacity upright WTS-LV model provides three times the battery life of the standard model. The Bore-Hole WTS-LV is designed to fit through a narrow opening such as a 30-centimeter borehole. The dual filter WTS-LV features two vertical intake 142 mm filter holders to allow simultaneous filtering using two different porosities. |
| Dataset-specific Instrument Name | Multicorer |
| Generic Instrument Name | Multi Corer |
| Dataset-specific Description | To supplement investigation of water-column TEIs near the seafloor, a plan was developed for mounting a trace metal-clean external-closure Niskin (Niskin-X) bottle to the stainless steel frame of the multicorer. See "Methods & Sampling" and the cruise reports for complete descriptions of this instrument. |
| Generic Instrument Description | The Multi Corer is a benthic coring device used to collect multiple, simultaneous, undisturbed sediment/water samples from the seafloor. Multiple coring tubes with varying sampling capacity depending on tube dimensions are mounted in a frame designed to sample the deep ocean seafloor. For more information, see Barnett et al. (1984) in Oceanologica Acta, 7, pp. 399-408. |
| Dataset-specific Instrument Name | Niskin sampler bottles |
| Generic Instrument Name | Niskin bottle |
| Dataset-specific Description | The ODF rosette casts were performed with a package consisting of a 36-bottle rosette frame, a 36-place carousel and 36 x 10.6 L Bullister-style Niskin sampler bottles. |
| Generic Instrument Description | A Niskin bottle (a next generation water sampler based on the Nansen bottle) is a cylindrical, non-metallic water collection device with stoppers at both ends. The bottles can be attached individually on a hydrowire or deployed in 12, 24, or 36 bottle Rosette systems mounted on a frame and combined with a CTD. Niskin bottles are used to collect discrete water samples for a range of measurements including pigments, nutrients, plankton, etc. |
| Dataset-specific Instrument Name | Beryllium-7 pump |
| Generic Instrument Name | Pump surface |
| Dataset-specific Description | Upper water-column ( |
| Generic Instrument Description | A source of uncontaminated near-surface seawater pumped onto the deck of the research vessel that can be sampled and analyzed. This pumped seawater supply is from an over-the-side pumping system, and is therefore different from the vessel underway seawater system. |
| Dataset-specific Instrument Name | Radium surface pump |
| Generic Instrument Name | Pump surface |
| Dataset-specific Description | Near-surface (~3 meters depth) seawater samples for analysis of radium isotopes were collected using a surface pump deployed by hand over the starboard quarter of RVIB Nathaniel B. Palmer. See "Methods & Sampling" and the cruise reports for complete descriptions of this instrument. |
| Generic Instrument Description | A source of uncontaminated near-surface seawater pumped onto the deck of the research vessel that can be sampled and analyzed. This pumped seawater supply is from an over-the-side pumping system, and is therefore different from the vessel underway seawater system. |
| Dataset-specific Instrument Name | SIO/ODF-designed automated oxygen titrator |
| Generic Instrument Name | Scripps Institution of Oceanography (SIO) ODF automated oxygen titrator |
| Dataset-specific Description | Dissolved oxygen was measured in discrete samples using an SIO/ODF-designed automated oxygen titrator. See "Methods & Sampling" and the cruise reports for complete descriptions of this system. |
| Generic Instrument Description | A bench-top, oxygen titrator system designed by the Ocean Data Facility (ODF) at the Scripps Institution of Oceanography that is based on the Winkler titration method. It measures dissolved oxygen using photometric end-point detection based on the absorption of 365nm wavelength ultra-violet light. Thiosulphate is typically dispensed from a Dosimat burette. The titration and data logging are controlled by ODF PC software compiled in LabView. |
| Dataset-specific Instrument Name | Trace-Metal Clean (GTC) CTD Rosette and Conventional ODF Rosette |
| Generic Instrument Name | Sea-Bird SBE 911plus CTD |
| Dataset-specific Description | See "Methods & Sampling" and the cruise reports for complete descriptions of these instruments and associated sensors. |
| Generic Instrument Description | [tethered, real-time] The Sea-Bird SBE 911 plus is a type of CTD instrument package for continuous measurement of conductivity, temperature and pressure. The SBE 911 plus includes the SBE 9plus Underwater Unit and the SBE 11plus Deck Unit (for real-time readout using conductive wire) for deployment from a vessel. The combination of the SBE 9 plus and SBE 11 plus is called a SBE 911 plus. The SBE 9 plus uses Sea-Bird's standard modular temperature and conductivity sensors (SBE 3 plus and SBE 4). The SBE 9 plus CTD can be configured with up to eight auxiliary sensors to measure other parameters including dissolved oxygen, pH, turbidity, fluorescence, light (PAR), light transmission, etc.). more information from Sea-Bird Electronics |
| Website | |
| Platform | RVIB Nathaniel B. Palmer |
| Report | |
| Start Date | 2023-11-29 |
| End Date | 2024-01-28 |
| Description | See more information at:
R2R https://www.rvdata.us/search/cruise/NBP2401
BODC https://www.bodc.ac.uk/resources/inventories/cruise_inventory/report/18091/
US GEOTRACES https://usgeotraces.ldeo.columbia.edu/content/gp17-ant
Description:
The U.S. GEOTRACES GP17-ANT expedition departed Punta Arenas, Chile on November 29th, 2023 and arrived in Lyttelton, New Zealand on January 28th, 2024. The cruise took place in the Amundsen Sea aboard the R/V Nathaniel B. Palmer with a team of 35 scientists led by Peter Sedwick (Old Dominion University), Phoebe Lam (University of California, Santa Cruz), and Robert Sherrell (Rutgers University). GP17 was planned as a two-leg expedition, with its first leg (GP17-OCE) as a southward extension of the 2018 GP15 Alaska-Tahiti expedition and this second leg (GP17-ANT) into coastal and shelf waters of Antarctica's Amundsen Sea. |
U.S. GEOTRACES extended its meridional transect, initiated on the 2018 GP15 Alaska-Tahiti expedition, south to the Antarctic ice edge and then east to Chile with GP17-OCE (December 2022 - January 2023). Because of the potentially important trace elements and isotopes (TEIs) inputs and transformations occurring in Antarctic waters and shelves, GP17 also had a second leg, GP17-ANT (November 29, 2023 - January 30, 2024) into coastal and shelf waters of Antarctica’s Amundsen Sea. Further information is available on the US GEOTRACES website.
NSF Project Title: Collaborative Research: Management and Implementation of US GEOTRACES GP17 Section: Amundsen Sea Sector of the Antarctic Continental Margin (GP17-ANT)
NSF Award Abstract:
This project will support the management and implementation of a 60-day research cruise to the Amundsen Sea sector of the Antarctic continental margin to collect samples for measurements of a broad suite of trace elements and isotopes ('TEIs'), as part of the U.S. GEOTRACES program. GEOTRACES is a global effort in the field of Chemical Oceanography, the goal of which is to understand the distributions of trace elements and their isotopes in the ocean. Determining the distributions of these elements and isotopes will increase the understanding of processes that shape their distributions and also the processes that depend on these elements. Key TEIs include essential micronutrients such as iron and zinc; 'tracers' such as aluminum, manganese, and isotopes of nitrogen, thorium and neodymium that can be used to investigate modern and ancient ocean processes; and elements such as lead that are indicative of human activities. In the Southern Ocean, the Antarctic continental margins are important as sources of micronutrient trace elements such as iron, which is required to support biological production and carbon export over the Antarctic shelf and in offshore waters of the Antarctic Circumpolar Current. Moreover, these regions are experiencing rapid environmental changes that are expected to impact oceanic circulation and biogeochemical cycles, for which TEIs provide crucial data needed to test and refine numerical models of the Earth system. The Amundsen Sea sector holds particular interest because of the pronounced, decadal-scale increases in the melting rates of glacial ice shelves that border the region, driven by intrusions of warm Circumpolar Deep Water onto the continental shelf. This melting has potentially major impacts on global sea level, on the formation of Antarctic Bottom Water in the Ross Sea, and on the regional ecosystem.
The cruise will comprise essential sampling operations (collection and shipboard processing) and ancillary measurements (hydrography, nutrients, algal pigments) in support of multiple, individual science projects, following the successful model of previous U.S. GEOTRACES cruises in the Atlantic, Pacific and Arctic ocean basins. The cruise will sample the ocean region between 100°W and 135°W, with stations ranging from 67°S in the Antarctic Circumpolar Current southward to the Amundsen Sea continental shelf, including stations adjacent to several rapidly melting ice shelves and in highly-productive shelf polynyas. Water column samples will be collected using conventional and trace-metal clean CTD-rosette systems, in-situ high-volume pumps, and a towed fish sampler or small boat, using established methods. Sampling time will also be provided for collection of sea ice, floating glacial ice, and seafloor sediments. To facilitate coordination with a complementary open-ocean cruise and ensure access to the study region to document the impact of biological processes, the cruise is planned for late austral summer (late January-late March). Beyond the disciplinary contributions, the proposed research will contribute knowledge concerning the cryosphere and its impacts on global sea level and ocean circulation, regional ecosystems and biological processes, ocean-atmosphere interactions, and past and future environmental change. The project will contribute to STEM education and outreach through the participation of an NSF-funded PolarTREC education professional, and a K-12 STEM program for students from underserved and underrepresented schools run by Rutgers University education specialists. To foster public engagement, the investigators will partner with the UCSC Science Communication Program to engage freelance science journalists to profile research in this spectacular and harsh Antarctic environment.
GEOTRACES is a SCOR sponsored program; and funding for program infrastructure development is provided by the U.S. National Science Foundation.
GEOTRACES gained momentum following a special symposium, S02: Biogeochemical cycling of trace elements and isotopes in the ocean and applications to constrain contemporary marine processes (GEOSECS II), at a 2003 Goldschmidt meeting convened in Japan. The GEOSECS II acronym referred to the Geochemical Ocean Section Studies To determine full water column distributions of selected trace elements and isotopes, including their concentration, chemical speciation, and physical form, along a sufficient number of sections in each ocean basin to establish the principal relationships between these distributions and with more traditional hydrographic parameters;
* To evaluate the sources, sinks, and internal cycling of these species and thereby characterize more completely the physical, chemical and biological processes regulating their distributions, and the sensitivity of these processes to global change; and
* To understand the processes that control the concentrations of geochemical species used for proxies of the past environment, both in the water column and in the substrates that reflect the water column.
GEOTRACES will be global in scope, consisting of ocean sections complemented by regional process studies. Sections and process studies will combine fieldwork, laboratory experiments and modelling. Beyond realizing the scientific objectives identified above, a natural outcome of this work will be to build a community of marine scientists who understand the processes regulating trace element cycles sufficiently well to exploit this knowledge reliably in future interdisciplinary studies.
Expand "Projects" below for information about and data resulting from individual US GEOTRACES research projects.
| Funding Source | Award |
|---|---|
| NSF Antarctic Sciences (NSF ANT) | |
| NSF Antarctic Sciences (NSF ANT) | |
| NSF Antarctic Sciences (NSF ANT) |