gov.noaa.nodc:0317020 eng utf8 dataset NOAA National Centers for Environmental Information ncei.info@noaa.gov https://www.ncei.noaa.gov/contact HTTPS NOAA Contact Information Information for contacts at NCEI. information custodian 2026-07-31T13:25:36Z ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) Nitrous Oxide and Nitrate Isotope discrete, profile measurements obtained during the NOAA Ship Ronald H. Brown cruise WCOA2021 (EXPOCODE 33RO20210613) in the North Pacific Ocean, US West Coast from 2021-06-13 to 2021-07-26 (NCEI Accession 0317020) 2026-07-23 publication 2026-07-23 creation International DOI Foundation (IDF) 10.25921/ds45-5y17 NOAA National Centers for Environmental Information gov.noaa.nodc:0317020 NCEI Archive Management System 0317020 NOAA National Centers for Environmental Information ncei.info@noaa.gov https://www.ncei.noaa.gov/contact HTTPS NCEI Contact Information Information for contacts at NCEI. information publisher Noah Gluschankoff Stanford University noahglu@gmail.com http://www.stanford.edu/ HTTP Stanford University website Institution web page information resourceProvider Stanford University http://www.stanford.edu/ HTTP Stanford University website Institution web page information resourceProvider Noah Gluschankoff Stanford University noahglu@gmail.com http://www.stanford.edu/ HTTP Stanford University website Institution web page information principalInvestigator Karen Casciotti Stanford University kcasciot@stanford.edu http://www.stanford.edu/ HTTP Stanford University website Institution web page information principalInvestigator Jen Karolewski Stanford University http://www.stanford.edu/ HTTP Stanford University website Institution web page information principalInvestigator Gluschankoff, Noah Stanford University http://www.stanford.edu/ HTTP Stanford University website Institution web page information author Casciotti, Karen Stanford University http://www.stanford.edu/ HTTP Stanford University website Institution web page information author Karolewski, Jen Stanford University http://www.stanford.edu/ HTTP Stanford University website Institution web page information author Stanford University http://www.stanford.edu/ HTTP Stanford University website Institution web page information contributor tableDigital This data package contains the discrete bottle (CTD profile) data of nitrous oxide (N2O) and nitrate (NO3) isotopes from the 2021 West Coast Ocean Acidification cruise. The cruise took place June 13 - July 26, 2021 aboard the NOAA Ship Ronald H. Brown. Samples were collected from Dana Point, California to Haida Gwaii, Canada. In this dataset, 70 unique stations were analyzed for N2O and NO3 isotopes. The dataset here was designed to obtain the first region-wide observations of N2O and NO3 isotopes throughout the California Current System (CCS) to understand the source of N2O in the CCS. This effort was conducted with the support of the coastal monitoring and research objectives of the NOAA Ocean Acidification Program (OAP). This dataset is available to the public for a wide variety of uses including scientific research and analysis. Funding Information: NOAA's Ocean Acidification Program (PMEL Sustained Ocean Acidification Biogeochemical and Ecological Survey Observations (PLS)) Funding Information: PMEL Sustained Ocean Acidification Large-Scale Survey Observations completed historicalArchive NOAA National Centers for Environmental Information ncei.info@noaa.gov https://www.ncei.noaa.gov/contact HTTPS NCEI Contact Information Information for contacts at NCEI. information pointOfContact asNeeded https://www.ncei.noaa.gov/access/metadata/landing-page/bin/gfx?id=gov.noaa.nodc:0317020 Preview graphic PNG 0317020 NCEI ACCESSION NUMBER 2026-07-22 publication DELTA NITROGEN-15 Delta Oxygen-18 DISSOLVED OXYGEN HYDROSTATIC PRESSURE nitrous oxide (N2O) SALINITY SIGMA-THETA WATER TEMPERATURE theme NODC DATA TYPES THESAURUS CTD Niskin bottle oxygen sensor salinometer temperature sensor instrument NODC INSTRUMENT TYPES THESAURUS chemical discrete sample physical profile theme NODC OBSERVATION TYPES THESAURUS NOAA Ship Ronald H. Brown platform NODC PLATFORM NAMES THESAURUS Stanford University dataCentre NODC COLLECTING INSTITUTION NAMES THESAURUS Stanford University dataCentre NODC SUBMITTING INSTITUTION NAMES THESAURUS Ocean Carbon and Acidification Data System (OCADS) US DOC; NOAA; Office of Oceanic and Atmospheric Research; Ocean Acidification Program (OAP) project NODC PROJECT NAMES THESAURUS Channel Islands National Marine Sanctuary Chumash Heritage National Marine Sanctuary Coastal Waters of Southeast Alaska and British Columbia Columbia River estuary - Washington/Oregon Greater Farallones National Marine Sanctuary Monterey Bay National Marine Sanctuary North Pacific Ocean Olympic Coast National Marine Sanctuary West Coast - US/Canada place NODC SEA AREA NAMES THESAURUS oceanography theme WMO_CategoryCode 2012-09-15 publication WCOA2021 project Cruise ID 33RO20210613 project EXPOCODE Ocean Acidification Program (OAP) Ocean Carbon and Acidification Data System (OCADS) Project project Ocean Acidification Search Keywords Coastal project Reference Section ID NOAA Ocean Acidification Observing Network PMEL Sustained Ocean Acidification Large-Scale Survey Observations project Research Projects EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > NITROGEN EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > OXYGEN EARTH SCIENCE > OCEANS > OCEAN PRESSURE > WATER PRESSURE EARTH SCIENCE > OCEANS > OCEAN TEMPERATURE > WATER TEMPERATURE EARTH SCIENCE > OCEANS > SALINITY/DENSITY > DENSITY EARTH SCIENCE > OCEANS > SALINITY/DENSITY > SALINITY theme Global Change Master Directory (GCMD) Science Keywords 2026 revision 24 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) Greenbelt MD https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords HTTPS GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian Discrete Sample Profile theme OCADS Study Type CTDOXYGEN_UMOL_KG CTDPRESSURE_DBAR CTDSAL_PSS78 CTDTMP_ITS90_DEG_C Pot_density d15n_alpha d15n_alpha_std d15n_beta d15n_beta_std d15n_bulk d15n_bulk_std d15n_no3 d15n_no3_std d17o_N2O d17o_N2O_std d18o_N2O d18o_N2O_std d18o_no3 d18o_no3_std n2o_conc n2o_conc_error sp sp_std theme Provider Variable Abbreviations CTD > Conductivity, Temperature, Depth NISKIN BOTTLES OXYGEN METERS > OXYGEN METERS SALINOMETERS TEMPERATURE SENSORS > TEMPERATURE SENSORS instrument Global Change Master Directory (GCMD) Instrument Keywords 2026 revision 24 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) Greenbelt MD https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords HTTPS GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian Ships platform Global Change Master Directory (GCMD) Platform Keywords 2026 revision 24 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) Greenbelt MD https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords HTTPS GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian Ronald H. Brown (call sign: WTEC, ICES code: 33RO, 1997-) platform ICES/SeaDataNet Ship Codes OCEAN > PACIFIC OCEAN > NORTH PACIFIC OCEAN place Global Change Master Directory (GCMD) Location Keywords 2026 revision 24 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) Greenbelt MD https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords HTTPS GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian British Columbia California Current Ecosystem Canada North Pacific Ocean Southern California Bight U.S. West Coast place Provider Geographic Names accessLevel: public otherRestrictions Cite as: Gluschankoff, Noah; Casciotti, Karen; Karolewski, Jen (2026). Nitrous Oxide and Nitrate Isotope discrete, profile measurements obtained during the NOAA Ship Ronald H. Brown cruise WCOA2021 (EXPOCODE 33RO20210613) in the North Pacific Ocean, US West Coast from 2021-06-13 to 2021-07-26 (NCEI Accession 0317020). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.25921/ds45-5y17. Accessed [date]. 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. otherRestrictions 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. license This dataset is licensed under the Creative Commons Attribution 4.0 International (CC BY 4.0) License. SPDX License: Creative Commons Attribution 4.0 International (CC-BY-4.0) Dissolved inorganic carbon (DIC), total alkalinity (TA), pH, temperature, salinity, oxygen, and nutrient data collected from discrete profile measurements during the National Oceanic and Atmospheric Administration Ocean Acidification Program (OAP) program cruise WCOA2021 (EXPOCODE 33RO20210613) in the northeast Pacific marine waters on NOAA Ship Ronald H. Brown from 2021-06-13 to 2021-07-26 (NCEI Accession 0260718) 2022-10-06 publication International DOI Foundation (IDF) https://doi.org/10.25921/tzxh-n954 NOAA National Centers for Environmental Information gov.noaa.nodc:0260718 https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0260718.html HTTPS https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0260718.html Related dataset information Feely, Richard A. NOAA Pacific Marine Environmental Laboratory https://www.pmel.noaa.gov/ HTTPS NOAA Pacific Marine Environmental Laboratory (PMEL) website Institution web page information author Carter, Brendan R. University of Washington Cooperative Institute for Climate, Ocean and Ecosystem Studies https://cicoes.uw.edu/ HTTPS University of Washington Cooperative Institute for Climate, Ocean and Ecosystem Studies (CICOES) website Institution web page information author Greeley, Dana NOAA Pacific Marine Environmental Laboratory https://www.pmel.noaa.gov/ HTTPS NOAA Pacific Marine Environmental Laboratory (PMEL) website Institution web page information author McCabe, Ryan M. NOAA Pacific Marine Environmental Laboratory ryan.mccabe@noaa.gov https://www.pmel.noaa.gov/ HTTPS NOAA Pacific Marine Environmental Laboratory (PMEL) website Institution web page information author Herndon, Julian University of Washington Joint Institute for the Study of the Atmosphere and Ocean https://cicoes.uw.edu/ HTTPS University of Washington Cooperative Institute for Climate, Ocean and Ecosystem Studies (CICOES) website Institution web page information author NOAA National Centers for Environmental Information (NCEI) publisher tableDigital crossReference project 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 2022-04 publication https://www.ncei.noaa.gov/products/ocean-carbon-acidification-data-system HTTPS https://www.ncei.noaa.gov/products/ocean-carbon-acidification-data-system OCADS website information NOAA National Centers for Environmental Information author NOAA National Centers for Environmental Information (NCEI) publisher documentDigital [accessed 2024-02-08] crossReference program Underway total alkalinity, water temperature, salinity and other variables collected from surface seawater during the NOAA Ship Ronald H. Brown 2021 West Coast Ocean Acidification cruise RBWCOA2021 (EXPOCODE 33RO20210613) in the North Pacific Ocean from 2021-06-14 to 2021-07-20 (NCEI Accession 0288994) 2024-02-16 publication International DOI Foundation (IDF) https://doi.org/10.25921/24h7-8b88 NOAA National Centers for Environmental Information gov.noaa.nodc:0288994 https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0288994.html HTTPS https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0288994.html Related dataset information Hunt, Christopher W. University of New Hampshire author Pierrot, Denis NOAA Atlantic Oceanographic and Meteorological Laboratory https://www.aoml.noaa.gov/ HTTPS NOAA Atlantic Oceanographic and Meteorological Laboratory (AOML) website Institution web page information author Barbero, Leticia Rosenstiel School of Marine, Atmospheric, and Earth Science Cooperative Institute for Marine and Atmospheric Studies https://cimas.earth.miami.edu/ HTTPS Rosenstiel School of Marine, Atmospheric, and Earth Science Cooperative Institute for Marine and Atmospheric Studies (CIMAS) website Institution web page information author Melrose, D. Christopher NOAA NMFS Northeast Fisheries Science Center author Vandemark, Douglas University of New Hampshire doug.vandemark@unh.edu author Wanninkhof, Rik NOAA Atlantic Oceanographic and Meteorological Laboratory https://www.aoml.noaa.gov/ HTTPS NOAA Atlantic Oceanographic and Meteorological Laboratory (AOML) website Institution web page information author NOAA National Centers for Environmental Information (NCEI) publisher tableDigital crossReference project NOAA West Coast Ocean Acidification Cruises (WCOA) and Harmful Algal Blooms cruise (NOAA HABs) 2022 publication https://www.ncei.noaa.gov/access/ocean-carbon-acidification-data-system/oceans/Coastal/WCOA.html HTTPS https://www.ncei.noaa.gov/access/ocean-carbon-acidification-data-system/oceans/Coastal/WCOA.html Related resource information NOAA National Centers for Environmental Information (NCEI) publisher documentDigital crossReference project eng; USA utf8 environment oceans -130.85 -117.75 32.08 52.4 2021-06-25 2021-07-26 This data package (Submission ID: BJ2EV1T6Y) was acquired by NCEI from the Scientific Data Integration System (SDIS) at the NOAA Pacific Marine Environmental Laboratory (PMEL) in accordance with the archival submission agreement between NCEI and PMEL. 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Originator data format 0.428 https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0317020.html HTTPS Web browser Project Metadata Navigate directly to the URL for a descriptive web page with download links. information https://doi.org/10.25921/ds45-5y17 HTTPS Web browser NCEI Dataset Landing Page Navigate directly to the URL for a descriptive web page with download links. information https://www.ncei.noaa.gov/archive/accession/oas/317020 HTTPS Web browser Descriptive Information Navigate directly to the URL for a descriptive web page with download links. information https://www.ncei.noaa.gov/archive/accession/download/317020 HTTPS Web browser HTTPS Navigate directly to the URL for data access and direct download. download ftp://ftp-oceans.ncei.noaa.gov/nodc/archive/arc0246/0317020/ FTP Any FTP client FTP These data are available through the File Transfer Protocol (FTP). FTP is no longer supported by most internet browsers. You may copy and paste the FTP link to the data into an FTP client (e.g., FileZilla or WinSCP). download dataset NCEI Accession 0317020 v1.1 was published. 2026-07-23T18:32:27Z NCEI Accession 0317020 v1.1 publication https://www.ncei.noaa.gov/archive/accession/0317020/1.1 HTTPS NCEI Accession 0317020 v1.1 published 2026-07-23T18:32:27Z download dataset Parameter or Variable: delta nitrogen-15 alpha; Abbreviation: d15n_alpha; Unit: permille; Observation type: Profile (discrete samples); Measured or calculated: MEASURED; Sampling instrument: Niskin bottle; Analyzing instrument: Thermo Fisher Delta V plus IRMS; Detailed sampling and analyzing information: This parameter is the d15N of the alpha (central position) of N2O. N2O sampling was performed at sea using silicone tubing from Niskin bottles into 160 mL borosilicate glass serum bottles (Wheaton). Water was first allowed to flow through the silicone tubing for a few seconds to remove any bubbles from the sampling stream. To begin sampling, sample flow was first paused by pinching the tubing, the tube was then inserted to the bottom of the glass serum bottle, and then flow from the tubing was gradually increased to prevent bubble injection. The glass bottles were filled until overflowing and then allowed to overflow at least two more times. A ~1 mL headspace of air was introduced to the bottle before it was capped with a grey butyl septum. Upon completion of sampling, bottles were immediately poisoned with 100 µL of saturated mercuric chloride solution before the septa were affixed with aluminum crimps. Bottles were mixed by inversion and stored in the dark and at room temperature until analysis. For analysis, a ~50 mL headspace of ultra-high purity nitrogen gas was introduced into each sample bottle. Analytical protocols using a custom on-line purge and trap system followed the methods outlined in McIlvin and Casciotti (2010) with technical updates described in Gluschankoff et al. (2025) that allowed samples to be purged within the sample bottle instead of transferring the seawater sample to a sparging flask. To extract N2O, each sample was purged with high-purity helium gas for 20 minutes at a rate of 60 mL min-1. After passing through a series of chemical and cryogenic traps to isolate and purify the N2O gas, N2O was chromatographically separated from any remaining CO2 and transferred to the IRMS where it was ionized to form N2O+ (m/z 44+, 45+, and 46+) and NO+ fragments (m/z 30+ and 31+), which were analyzed simultaneously using a five-collector array (McIlvin & Casciotti, 2010). Raw N2O data from the IRMS were corrected using pyisotopomer, a streamlined python package (Kelly et al., 2023). Data were normalized to a reference gas, corrected based on N2O quantity, and then underwent a log-log scale normalization to three N2O reference materials. Finally, ‘scrambling coefficients’ were calculated and applied to the data to account for rearrangement of nitrogen atoms that occurs during ionization and fragmentation to produce NO+ ions from the N2O sample (Frame & Casciotti, 2010; Kelly et al., 2021, 2023; Yoshida & Toyoda, 2000).; Uncertainty: 0.66-1.02 permille. Samples with low N2O concentration typically have greater uncertainty.; Quality flag convention: N2O_FLAG; WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn.; Method reference: Frame, C. H., & Casciotti, K. L. (2010). Biogeochemical controls and isotopic signatures of nitrous oxide production by a marine ammonia-oxidizing bacterium. Biogeosciences, 7(9), 2695–2709. https://doi.org/10.5194/bg-7-2695-2010 Gluschankoff, N., McGoran, H. J., & Casciotti, K. L. (2025). The Effects of Biogeochemistry and Water Mass Mixing on the Distribution of Nitrous Oxide in the Tropical South Pacific. Global Biogeochemical Cycles, 39(6), e2024GB008267. https://doi.org/10.1029/2024GB008267 Kelly, C. L., Manning, C., Frey, C., Kaiser, J., Gluschankoff, N., & Casciotti, K. L. (2023). Pyisotopomer: A Python package for obtaining intramolecular isotope ratio differences from mass spectrometric analysis of nitrous oxide isotopocules. Rapid Communications in Mass Spectrometry, 37(11), e9513. https://doi.org/10.1002/rcm.9513 Kelly, C. L., Travis, N. M., Baya, P. A., & Casciotti, K. L. (2021). Quantifying Nitrous Oxide Cycling Regimes in the Eastern Tropical North Pacific Ocean With Isotopomer Analysis. Global Biogeochemical Cycles, 35(2), e2020GB006637. https://doi.org/https://doi.org/10.1029/2020GB006637 McIlvin, M. R., & Casciotti, K. L. (2010). Fully automated system for stable isotopic analyses of dissolved nitrous oxide at natural abundance levels. Limnology and Oceanography: Methods, 8(2), 54–66. https://doi.org/https://doi.org/10.4319/lom.2010.8.54 Yoshida, N., & Toyoda, S. (2000). Constraining the atmospheric N2O budget from intramolecular site preference in N2O isotopomers. Nature, 405(6784), 330–334. https://doi.org/10.1038/35012558; Researcher name: Noah Gluschankoff; Researcher institution: Stanford University Parameter or Variable: delta nitrogen-15 alpha standard deviation; Abbreviation: d15n_alpha_std; Unit: permille; Observation type: Profile (discrete samples); Measured or calculated: CALCULATED; Analyzing instrument: Thermo Fisher Delta V plus IRMS; Detailed sampling and analyzing information: This variable is the standard deviation of duplicate discrete measurements. Methodology is same as for variable above. Parameter or Variable: delta nitrogen-15 beta; Abbreviation: d15n_beta; Unit: permille; Observation type: Profile (discrete samples); Sampling instrument: Niskin bottle; Analyzing instrument: Thermo Fisher Delta V plus IRMS; Detailed sampling and analyzing information: This parameter is the d15N of the beta (outer position) of N2O. Sampling, analysis methodology, and references same as for d15n_alpha (delta nitrogen-15 alpha).; Uncertainty: 0.80-1.47 permille. Samples with low N2O concentration typically have greater uncertainty.; Quality flag convention: N2O_FLAG; WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn.; Researcher name: Noah Gluschankoff; Researcher institution: Stanford University Parameter or Variable: delta nitrogen-15 beta standard deviation; Abbreviation: d15n_beta_std; Unit: permille; Analyzing instrument: Thermo Fisher Delta V plus IRMS; Detailed sampling and analyzing information: This variable is the standard deviation of duplicate discrete measurements. Methodology is same as for variable above. Parameter or Variable: site preference; Abbreviation: sp; Unit: Permille; Observation type: Profile (discrete samples); Sampling instrument: Niskin bottle; Analyzing instrument: Thermo Fisher Delta V plus IRMS; Detailed sampling and analyzing information: This parameter is the site preference (d15n_alpha minus d15n_beta) of N2O. Sampling, analysis methodology, and references same as for d15n_alpha (delta nitrogen-15 alpha).; Uncertainty: 1.09-2.25 permille. Samples with low N2O concentration typically have greater uncertainty.; Quality flag convention: N2O_FLAG; WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn.; Researcher name: Noah Gluschankoff; Researcher institution: Stanford University Parameter or Variable: site preference standard deviation; Abbreviation: sp_std; Unit: permille; Analyzing instrument: Thermo Fisher Delta V plus IRMS; Detailed sampling and analyzing information: This variable is the standard deviation of duplicate discrete measurements. Methodology is same as for variable above. Parameter or Variable: delta nitrogen-15 bulk; Abbreviation: d15n_bulk; Unit: permille; Observation type: Profile (discrete samples); Sampling instrument: Niskin bottle; Analyzing instrument: Thermo Fisher Delta V plus IRMS; Detailed sampling and analyzing information: This parameter is the average d15N of the alpha (central position) and beta (outer position) of N2O. Sampling, analysis methodology, and references same as for d15n_alpha (delta nitrogen-15 alpha).; Uncertainty: 0.49-0.58 permille. Samples with low N2O concentration typically have greater uncertainty.; Quality flag convention: N2O_FLAG; WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn.; Researcher name: Noah Gluschankoff; Researcher institution: Stanford University Parameter or Variable: delta nitrogen-15 bulk standard deviation; Abbreviation: d15n_bulk_std; Unit: permille; Analyzing instrument: Thermo Fisher Delta V plus IRMS; Detailed sampling and analyzing information: This variable is the standard deviation of duplicate discrete measurements. Methodology is same as for variable above.; Quality flag convention: WOCE Flag Parameter or Variable: delta oxygen-17; Abbreviation: d17o_N2O; Unit: permille; Observation type: Profile (discrete samples); Sampling instrument: Niskin bottle; Analyzing instrument: Thermo Fisher Delta V plus IRMS; Detailed sampling and analyzing information: This parameter is the d17O of N2O. Sampling, analysis methodology, and references same as for d15n_alpha (delta nitrogen-15 alpha).; Uncertainty: 1.02; Quality flag convention: N2O_FLAG; WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn.; Researcher name: Noah Gluschankoff; Researcher institution: Stanford University Parameter or Variable: delta oxygen-17 standard deviation; Abbreviation: d17o_N2O_std; Unit: permille; Analyzing instrument: Thermo Fisher Delta V plus IRMS; Detailed sampling and analyzing information: This variable is the standard deviation of duplicate discrete measurements. Methodology is same as for variable above. Parameter or Variable: delta Oxygen-18 - nitrous oxide; Abbreviation: d18o_N2O; Unit: permille; Observation type: Profile (discrete samples); Sampling instrument: Niskin bottle; Analyzing instrument: Thermo Fisher Delta V plus IRMS; Detailed sampling and analyzing information: This parameter is the d18O of N2O. Sampling, analysis methodology, and references same as for d15n_alpha (delta nitrogen-15 alpha).; Uncertainty: 0.71-1.10 permille. Samples with low N2O concentration typically have greater uncertainty.; Quality flag convention: N2O_FLAG; WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn.; Researcher name: Noah Gluschankoff; Researcher institution: Stanford University Parameter or Variable: delta Oxygen-18 - nitrous oxide standard deviation; Abbreviation: d18o_N2O_std; Unit: permille; Analyzing instrument: Thermo Fisher Delta V plus IRMS; Detailed sampling and analyzing information: This variable is the standard deviation of duplicate discrete measurements. Methodology is same as for variable above. Parameter or Variable: Nitrous oxide (N2O) concentration; Abbreviation: n2o_conc; Unit: nanomoles per liter; Observation type: Profile (discrete samples); Sampling instrument: Niskin bottle; Analyzing instrument: Thermo Fisher Delta V plus IRMS; Detailed sampling and analyzing information: A 50 mL headspace of N2 was introduced into each 160 mL Wheaton glass bottle. Afterward, each sample bottle was weighed to determine the total weight of sample, glass bottle, septum, and crimp. By comparison, an empty glass bottle, septum, and crimp consistently weighed 110 +/- 1 g. Therefore, to determine the seawater sample weight, 110 g was subtracted from the total weight, and the difference was converted to volume (L) using a constant density (1.026 kg L-1) for all seawater samples with salinity >30. For samples with salinities <30, sample-specific densities were calculated using the Gibbs-SeaWater (GSW) Toolbox (T. J. McDougall & Barker, 2011) and used to calculate sample volume. The quantity of N2O in each sample (nanomoles) was calculated using the integrated m/z=44 peak area in Volt-seconds (Vs) from the IRMS, multiplied by an empirically derived conversion factor of 0.460 ± 0.042 nmol (Vs)-1. Determining N2O concentrations using IRMS relies on robust calibration, but is a routine procedure that has been applied across multiple laboratories (e.g., Bourbonnais et al., 2023; Frey et al., 2024). In this study, the conversion factor was determined nine separate times throughout the timeframe of analyses (November 2022 – April 2024) to ensure no significant shifts in instrument sensitivity occurred. Finally, the quantity of N2O was divided by the volume of sample analyzed to determine the N2O concentration in nmol L-1. The N2O concentration error was determined using the uncertainty in the nmol (Vs)-1 conversion factor described above.; Quality flag convention: N2O_FLAG; WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn.; Method reference: McIlvin, M. R., & Casciotti, K. L. (2010). Fully automated system for stable isotopic analyses of dissolved nitrous oxide at natural abundance levels. Limnology and Oceanography: Methods, 8(2), 54–66. https://doi.org/https://doi.org/10.4319/lom.2010.8.54; Gluschankoff, N., McGoran, H. J., & Casciotti, K. L. (2025). The Effects of Biogeochemistry and Water Mass Mixing on the Distribution of Nitrous Oxide in the Tropical South Pacific. Global Biogeochemical Cycles, 39(6), e2024GB008267. https://doi.org/10.1029/2024GB008267; Bourbonnais, A., Chang, B. X., Sonnerup, R. E., Doney, S. C., & Altabet, M. A. (2023). Marine N2O cycling from high spatial resolution concentration, stable isotopic and isotopomer measurements along a meridional transect in the eastern Pacific Ocean. Frontiers in Marine Science, 10. https://www.frontiersin.org/articles/10.3389/fmars.2023.1137064; Frey, C., Tang, W., Ward, B. B., & Lehmann, M. F. (2024). Sample preservation methods for nitrous oxide concentration and isotope ratio measurements in aquatic environments. Limnology and Oceanography: Methods, 22(10), 771–788. https://doi.org/10.1002/lom3.10638; McDougall, T. J., & Barker, P. M. (2011). Getting started with TEOS-10 and the Gibbs Seawater (GSW) Oceanographic Toolbox. Trevor J McDougall.; Researcher name: Noah Gluschankoff; Researcher institution: Stanford University Parameter or Variable: Calculated uncertainty nitrous oxide (N2O) concentration; Abbreviation: n2o_conc_error; Unit: nanomoles per liter; Analyzing instrument: Thermo Fisher Delta V plus IRMS; Detailed sampling and analyzing information: Methodology and references same as n2o concentration measurement above. The N2O concentration error was determined using the uncertainty in the nmol (Vs)-1 conversion factor described above. Parameter or Variable: nitrate delta oxygen-18; Abbreviation: d18o_no3; Unit: permille; Observation type: Profile (discrete samples); Sampling instrument: Niskin bottle; Analyzing instrument: Thermo Fisher Delta V plus IRMS; Detailed sampling and analyzing information: This parameter is the d18O of NO3. Sampling for NO3- isotopes first involved triple rinsing and then filling 500 mL polycarbonate Nalgene bottles using silicone tubing from the same Niskin bottles sampled for N2O. After the bottles were filled, they were returned to the lab where a 60 mL plastic syringe was triple rinsed with seawater sample and passed through a 0.2 µm Sterivex filter before finally filtering seawater into a 60 mL HDPE bottles. This last step was repeated for each Niskin bottle sampled, resulting in two 60 mL subsamples per depth. Sample bottles were filled to the shoulder and then immediately frozen and stored upright at -20ºC. Samples remained frozen until preparation for analysis. The δ15N and δ18O of NO3- were determined using the ‘denitrifier method’, where sufficient [NO3-] was observed, typically above 0.3 µmol kg-1. Briefly, NO3- samples were converted to N2O followed by isotopic analysis on a Thermo Fisher Delta V Plus IRMS (Casciotti et al., 2002; McIlvin & Casciotti, 2011; Sigman et al., 2001; Weigand et al., 2016). Six aliquots of the NO3- isotope calibration standards USGS 32, 34, and 35 were analyzed alongside each batch of samples to correct for drift and blanks. Samples with NO2- concentrations greater than 1% of the sum of [NO3- ] and [NO2-] were treated with sulfamic acid to remove NO2- before the denitrifier method was performed (Granger & Sigman, 2009). Samples were analyzed in duplicate, and the mean sample replicate standard deviation for δ18O-NO3- and δ15N-NO3- were 0.27‰ and 0.21‰, respectively.; Uncertainty: 0.27; Quality flag convention: no3_FLAG; WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn.; Method reference: Casciotti, K. L., Sigman, D. M., Hastings, M. G., Böhlke, J. K., & Hilkert, A. (2002). Measurement of the Oxygen Isotopic Composition of Nitrate in Seawater and Freshwater Using the Denitrifier Method. Analytical Chemistry, 74(19), 4905–4912. https://doi.org/10.1021/ac020113w; Granger, J., & Sigman, D. M. (2009). Removal of nitrite with sulfamic acid for nitrate N and O isotope analysis with the denitrifier method. Rapid Communications in Mass Spectrometry, 23(23), 3753–3762. https://doi.org/10.1002/rcm.4307; McIlvin, M. R., & Casciotti, K. L. (2011). Technical Updates to the Bacterial Method for Nitrate Isotopic Analyses. Analytical Chemistry, 83(5), 1850–1856. https://doi.org/10.1021/ac1028984; Sigman, D. M., Casciotti, K. L., Andreani, M., Barford, C., Galanter, M., & Böhlke, J. K. (2001). A Bacterial Method for the Nitrogen Isotopic Analysis of Nitrate in Seawater and Freshwater. Analytical Chemistry, 73(17), 4145–4153. https://doi.org/10.1021/ac010088e; Weigand, M. A., Foriel, J., Barnett, B., Oleynik, S., & Sigman, D. M. (2016). Updates to instrumentation and protocols for isotopic analysis of nitrate by the denitrifier method. Rapid Communications in Mass Spectrometry, 30(12), 1365–1383. https://doi.org/10.1002/rcm.7570; Researcher name: Noah Gluschankoff; Jen Karolewski; Researcher institution: Stanford University Parameter or Variable: nitrate delta oxygen-18 standard deviation; Abbreviation: d18o_no3_std; Unit: permille; Analyzing instrument: Thermo Fisher Delta V plus IRMS; Detailed sampling and analyzing information: This value represents a calculated standard deviation value for duplicate measurements of the variable above. Parameter or Variable: nitrate delta oxygen-18; Abbreviation: d15n_no3; Unit: permille; Observation type: Profile (discrete samples); Sampling instrument: Niskin bottle; Analyzing instrument: Thermo Fisher Delta V plus IRMS; Detailed sampling and analyzing information: This parameter is the d15N of NO3. Sampling, analysis, and methodology same as for no3_d18o.; Uncertainty: 0.21; Quality flag convention: no3_FLAG; WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn.; Researcher name: Noah Gluschankoff; Jen Karolewski; Researcher institution: Stanford University Parameter or Variable: nitrate delta nitrogen-15 standard deviation; Abbreviation: d15n_no3_std; Unit: permille; Analyzing instrument: Thermo Fisher Delta V plus IRMS; Detailed sampling and analyzing information: This value represents a calculated standard deviation value for duplicate measurements of the variable above. Parameter or Variable: Sigma-theta (Potential density anomaly); Abbreviation: Pot_density; Unit: kg per m3; Detailed sampling and analyzing information: Potential density anomaly (σθ = potential density minus 1000 kg m-3) was calculated using the python GSW toolbox.; Method reference: McDougall, T. J., & Barker, P. M. (2011). Getting started with TEOS-10 and the Gibbs Seawater (GSW) Oceanographic Toolbox. Trevor J McDougall. Parameter or Variable: CTD temperature, ITS-90 scale; Abbreviation: CTDTMP_ITS90_DEG_C; Unit: °C; Detailed sampling and analyzing information: We refer data users to the primary dataset for this cruise for CTD metadata information. CTD salinity, temperature, oxygen, and density are included for data users to conduct their own calculations with this dataset. https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0260718.html Parameter or Variable: CTD salinity; Abbreviation: CTDSAL_PSS78; Unit: 1978 Practical Salinity Scale; Detailed sampling and analyzing information: We refer data users to the primary dataset for this cruise for CTD metadata information. CTD salinity, temperature, oxygen, and density are included for data users to conduct their own calculations with this dataset. https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0260718.html; Quality flag convention: CTDSAL_flag, WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn. Parameter or Variable: CTD Oxygen; Abbreviation: CTDOXYGEN_UMOL_KG; Unit: micromoles/kg; Detailed sampling and analyzing information: We refer data users to the primary dataset for this cruise for CTD metadata information. CTD salinity, temperature, oxygen, and density are included for data users to conduct their own calculations with this dataset. https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0260718.html; Quality flag convention: CTDOXY_flag, WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value, 5 = value not reported, 6 = mean of replicate measurements, 9 = sample not drawn. Parameter or Variable: CTD pressure; Abbreviation: CTDPRESSURE_DBAR; Unit: decibars; Detailed sampling and analyzing information: We refer data users to the primary dataset for this cruise for CTD metadata information. CTD salinity, temperature, oxygen, and density are included for data users to conduct their own calculations with this dataset. https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0260718.html asNeeded Metadata are developed, maintained and distributed by NCEI. Updates are performed as needed to maintain currentness. NOAA National Centers for Environmental Information custodian CTD CTD Conductivity-Temperature-Depth probe Niskin bottle Niskin bottle Device for obtaining samples of seawater at a specific depth Why special entry for Niskin bottle but no entry for Nansen bottle? oxygen sensor oxygen sensor Any instrument that measures oxygen content in a compound. salinometer salinometer generic salinometer use salinometer when the instrument type used is unclear but the data include salinity measurements temperature sensor temperature sensor A sensor used to measure temperature. NOAA Ship Ronald H. Brown Updated information from ICES for UNITED STATES platform Ronald H. Brown Flag : UNITED STATES - US (ISO Country Code) Call Sign : WTEC Title : NOAA Ship Platform Class : Research vessel IMO : 9105786 Pennant : R 104 Commissioned Date : 1997-07-19 Current Length : 83.5 Built : 1997 Information Source : http://www.moc.noaa.gov/rb/index.html (URL) Lloyds URL : http://www.seasearcher.com/lmiu/vessels/overview.htm?vesselID=277516 *General Comments:* Name RESEARCHER II planned during build was never used.