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    • Surface Ocean CO2 Atlas Database Version 2025 (SOCATv2025) (NCEI Accession 0304549)

    Metadata Updated: September 2, 2025

    The ocean absorbs one quarter of the global CO2 emissions from human activity. The community-led Surface Ocean CO2 Atlas (www.socat.info) is key for the quantification of ocean CO2 uptake and its variation, now and in the future. SOCAT version 2025 has quality-controlled in situ surface ocean fCO2 (fugacity of CO2) measurements on ships, moorings, sailing yachts, autonomous and drifting surface platforms for the global ocean and coastal seas from 1957 to 2025. The main SOCAT synthesis and gridded products contain fCO2 values with an estimated accuracy of better than 5 μatm. Sensor fCO2 data with an estimated accuracy of better than 10 μatm are separately available. During secondary quality control, marine scientists assign a flag to each data set, as well as WOCE flags of 2 (good), 3 (questionable) or 4 (bad) to individual fCO2 values. Data sets are assigned flags of A and B for an estimated accuracy of better than 2 μatm, flag of C (and D) for an accuracy of better than 5 μatm and a flag of E for an accuracy of better than 10 μatm. Bakker et al. (2016) describe the quality control criteria used from SOCAT version 3 onward. SOCAT quality control cookbooks provide quality control updates (www.socat.info), with (Gkritzalis et al., 2024) used for version 2025. Quality control comments for individual data sets can be accessed via the SOCAT Data Set Viewer (www.socat.info). All data sets, where data quality has been deemed acceptable, have been made public. The main SOCAT synthesis files and the gridded products contain all data sets with an estimated accuracy of better than 5 µatm (data set flags of A to D) and fCO2 values with a WOCE flag of 2. Access to data sets with an estimated accuracy of better than 10 µatm (flag of E) and fCO2 values with flags of 3 and 4 is via additional data products and the Data Set Viewer (Table 8 in Bakker et al., 2016). SOCAT publishes a global gridded product with a 1° longitude by 1° latitude resolution without gap filling. A second product with a higher resolution of 0.25° longitude by 0.25° latitude is available for the coastal seas. The gridded products contain all data sets with an estimated accuracy of better than 5 µatm (data set flags of A to D) and fCO2 values with a WOCE flag of 2. Gridded products are available monthly, per year and per decade. Two powerful, interactive, online viewers, the Data Set Viewer and the Gridded Data Viewer (www.socat.info), enable investigation of the SOCAT synthesis and gridded data products. SOCAT data products can be downloaded. Matlab code is available for reading these files. Ocean Data View also provides access to the SOCAT data products (www.socat.info). SOCAT data products are discoverable, accessible and citable. The SOCAT Data Use Statement (www.socat.info) asks users to generously acknowledge the contribution of SOCAT scientists by invitation to co-authorship, especially for data providers in regional studies, and/or reference to relevant scientific articles. It also asks users to cite the relevant SOCAT data set, the relevant methods paper(s), and to use acknowledgement text (https://socat.info/index.php/citing-socat/). The SOCAT website (www.socat.info) provides a single access point for online viewers, downloadable data sets, the Data Use Statement, a list of contributors and an overview of scientific publications on SOCAT and using SOCAT. Automation of data upload and initial data checks have allowed annual releases of SOCAT from version 4 onwards. Automation of metadata upload is ongoing. SOCAT is used for quantification of ocean CO2 uptake and ocean acidification and for evaluation of earth system models and sensor data. SOCAT products inform on ocean CO2 uptake in the annual Global Carbon Budget since 2013. SOCAT is a key element of the World Meteorological Organization’s (WMO) Global Greenhouse Gas Watch (G3W) program and is a key resource for Copernicus’ evaluations. The annual SOCAT releases by the SOCAT scientific community contribute to United Nations (UN) Sustainable Development Goal (SDG) 13 and SDG 14 (Life Below Water), and to the UN Decade of Ocean Science for Sustainable Development. However, since 2022 SOCAT critically relies on support provided by the Pacific Marine Environmental Laboratory of the National Oceanic and Atmospheric Administration in the US. This has been sufficient to keep the basic operation running, however this limited support has resulted in SOCAT data architecture not being updated, leading to a system with limited resilience that is highly vulnerable to external factors. Hundreds of peer-reviewed scientific publications and high-impact reports cite SOCAT. The SOCAT community-led synthesis product is a key step in the value chain based on in situ surface ocean carbon measurements, which provides policy makers with critical information on ocean CO2 uptake for policy makers. The need for accurate knowledge of global ocean CO2 uptake and its (future) variation makes sustained funding of in situ surface ocean CO2 observations and their synthesis imperative.

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    License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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    Dates

    Metadata Date 2025-07-28T13:03:51Z
    Metadata Created Date June 1, 2025
    Metadata Updated Date September 2, 2025
    Reference Date(s) May 30, 2025 (publication), June 25, 2025 (revision)
    Frequency Of Update asNeeded

    Metadata Source

    Harvested from NOAA/NESDIS/ncei/accessions

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    Additional Metadata

    Resource Type Dataset
    Metadata Date 2025-07-28T13:03:51Z
    Metadata Created Date June 1, 2025
    Metadata Updated Date September 2, 2025
    Reference Date(s) May 30, 2025 (publication), June 25, 2025 (revision)
    Responsible Party (Point of Contact)
    Contact Email
    Guid gov.noaa.nodc:0304549
    Access Constraints Cite as: Bakker, Dorothee C. E.; Alin, Simone R.; Aramaki, Takafumi; Barbero, Leticia; Bates, Nicholas; Gkritzalis, Thanos; Jones, Steve D.; Kozyr, Alex; Lauvset, Siv K.; Macovei, Vlad A.; Metzl, Nicolas; Munro, David R.; Nakaoka, Shin-ichiro; O'Brien, Kevin M.; Olsen, Are; Pierrot, Denis; Steinhoff, Tobias; Sullivan, Kevin F.; Sutton, Adrienne J.; Sweeney, Colm; Wada, Chisato; Wanninkhof, Rik; Akl, John; Arbilla, Lisandro A.; Azetsu-Scott, Kumiko; Battisti, Roman; Beatty, Cory M.; Becker, Meike; Benoit-Cattin, Alice; Berghoff, Carla F.; Bittig, Henry C.; Bonin, Jennifer A.; Bott, Randy; Bozzano, Roberto; Burger, Eugene F.; Brunetti, Fabio; Cantoni, Carolina; Castelli, Giuliano; Chambers, Don P.; Chierici, Melissa; Corbo, Andrea; Cronin, Margot; Cross, Jessica N.; Currie, Kim I.; Dentico, Carlotta; Emerson, Steven R.; Enochs, Ian C.; Enright, Matt P.; Enyo, Kazutaka; Ericson, Ylva; Evans, Wiley; Fay, Amanda R.; Feely, Richard A.; Fragiacomo, Elena; Fransson, Agneta; Gehrung, Martina; Giani, Michele; Glockzin, Michael; Hamnca, Siyabulela; Holodkov, Nikola; Hoppema, Mario; Ibánhez, J. Severino P.; Kadono, Koji; Kamb, Linus; Kralj, Martina; Kristensen, Torstein; Laudicella, V. Alessandro; Lefèvre, Nathalie; Leseurre, Coraline; Lo Monaco, Claire; Maenner Jones, Stacy; Maenza, Reinaldo A.; McAuliffe, Anna M.; Mdokwana, Baxolele; Monacci, Natalie M.; Musielewicz, Sylvia; Neill, Craig; Newberger, Tim; Nojiri, Yukihiro; Ohman, Mark D.; Ólafsdóttir, Sólveig Rósa; Olivier, Léa; Omar, Abdirahman M.; Osborne, John; Pensieri, Sara; Petersen, Wilhelm; Plueddemann, Albert J.; Rehder, Gregor; Roden, Nicholas P.; Rutgersson, Anna; Sallée, Jean-Baptiste; Sanders, Richard; Sarpe, Dirk; Schirnick, Carsten; Schlitzer, Reiner; Send, Uwe; Skjelvan, Ingunn; Sutherland, Stewart C.; T'Jampens, Michiel; Tamsitt, Veronica; Telszewski, Maciej; Theetaert, Hannelore; Tilbrook, Bronte; Trull, Tom; Tsanwani, Mutshutshu; van de Velde, Sebastiaan; van Heuven, Steven M. A. C.; Veccia, Martín H.; Voynova, Yoana G.; Weller, Robert A.; Williams, Nancy L. (2025). Surface Ocean CO2 Atlas Database Version 2025 (SOCATv2025) (NCEI Accession 0304549). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.25921/648f-fv35. Accessed [date]., 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.
    Bbox East Long 180
    Bbox North Lat 90
    Bbox South Lat -90
    Bbox West Long -180
    Coupled Resource
    Frequency Of Update asNeeded
    Graphic Preview Description Preview graphic
    Graphic Preview File https://www.ncei.noaa.gov/access/metadata/landing-page/bin/gfx?id=gov.noaa.nodc:0304549
    Graphic Preview Type PNG
    Harvest Object Id e38f0753-e3dd-4403-a886-2d43411496a5
    Harvest Source Id c084a438-6f6b-470d-93e0-16aeddb9f513
    Harvest Source Title NOAA/NESDIS/ncei/accessions
    Licence accessLevel: Public
    Lineage
    Metadata Language eng
    Metadata Type geospatial
    Old Spatial {"type": "Polygon", "coordinates": [[[-180.0, -90.0], [180.0, -90.0], [180.0, 90.0], [-180.0, 90.0], [-180.0, -90.0]]]}
    Progress completed
    Spatial Data Service Type
    Spatial Reference System
    Spatial Harvester True
    Temporal Extent Begin 1957-10-22
    Temporal Extent End 2025-01-31

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