Surface Ocean CO2 Atlas Database Version 2024 (SOCATv2024) (NCEI Accession 0293257)

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 2024 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 oceans and coastal seas from 1957 to 2023. The main 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 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, flags 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 in SOCAT versions 3 to 2024. 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. 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 and using SOCAT. Automation of data upload and initial data checks allows annual releases of SOCAT from version 4 onward. SOCAT is used for quantification of ocean CO2 uptake and ocean acidification and for evaluation of climate models and sensor data. SOCAT products inform the annual Global Carbon Budget since 2013. The annual SOCAT releases by the SOCAT scientific community are a Voluntary Commitment for United Nations Sustainable Development Goal 14.3 (Reduce Ocean Acidification) (#OceanAction20464). More broadly the SOCAT releases contribute to UN SDG 13 (Climate Action) and SDG 14 (Life Below Water), and to the UN Decade of Ocean Science for Sustainable Development. 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 inorganic carbon measurements of the oceans, which provides policy makers with critical information on ocean CO2 uptake in climate negotiations. 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.

海洋吸收了人类活动产生的全球二氧化碳排放量的四分之一。由科研社区主导的海洋表面二氧化碳图集（Surface Ocean CO2 Atlas, SOCAT，官网www.socat.info）是量化当前及未来海洋二氧化碳吸收量及其变化的核心数据集。2024版SOCAT包含1957年至2023年间，全球海洋及近岸海域中，由船舶、锚系观测平台、帆船、自主及漂流式表面观测平台获取的、经过质量控制的原位表层海水二氧化碳逸度（fugacity of CO2, fCO2）实测数据。其核心合成产品与网格化产品所包含的fCO2数据，估算精度优于5微大气压（μatm）；而估算精度优于10μatm的传感器fCO2数据则单独发布。在质量控制环节，海洋科学家会为每个数据集赋予质量标记，并为单个fCO2值标注世界海洋环流实验（World Ocean Circulation Experiment, WOCE）标记：2代表合格、3代表存疑、4代表不合格。数据集标记规则如下：精度优于2μatm的数据集标记为A与B，精度优于5μatm的标记为C与D，精度优于10μatm的标记为E。Bakker等人（2016）阐述了SOCAT第3版至2024版所采用的质量控制标准。单个数据集的质量控制注释可通过SOCAT数据集查看器（www.socat.info）查询。所有质量合格的数据集均已对外公开。SOCAT核心合成文件与网格化产品包含的是：估算精度优于5μatm（数据集标记为A至D）且WOCE标记为2的fCO2数据。而估算精度优于10μatm（标记为E）的数据集，以及WOCE标记为3和4的fCO2数据，需通过额外数据产品及数据集查看器获取（详见Bakker等人2016年发表论文中的表8）。SOCAT发布的全球网格化产品分辨率为1°经度×1°纬度，未进行数据间隙填补。另有一款适用于近岸海域的高分辨率网格化产品，分辨率为0.25°经度×0.25°纬度。网格化产品包含所有估算精度优于5μatm（数据集标记为A至D）且WOCE标记为2的数据集。网格化产品支持按月、按年及按十年周期获取。SOCAT官网设有两款功能强大的交互式在线查看器：数据集查看器与网格化数据查看器（www.socat.info），可用于探究SOCAT合成数据与网格化数据产品。SOCAT数据产品支持下载，同时提供用于读取相关文件的Matlab代码。Ocean Data View软件同样可访问SOCAT数据产品（www.socat.info）。SOCAT数据产品具备可发现性、可访问性与可引用性。SOCAT数据使用声明（www.socat.info）要求用户通过邀请合著（尤其针对区域研究中的数据提供者）及/或引用相关学术论文的方式，充分致谢SOCAT科研团队的贡献。SOCAT官网（www.socat.info）提供了在线查看器、可下载数据集、数据使用声明、贡献者列表以及关于SOCAT及使用SOCAT的学术出版物概览的统一入口。自SOCAT第4版起，数据上传自动化与初步数据检查功能实现了年度更新发布。SOCAT可用于量化海洋二氧化碳吸收量与海洋酸化，以及评估气候模型与传感器数据。自2013年起，SOCAT产品被用于编制年度全球碳预算。SOCAT科研团队的年度数据发布是联合国可持续发展目标14.3（减缓海洋酸化）（#OceanAction20464）的自愿承诺。更广泛而言，SOCAT数据发布助力联合国可持续发展目标13（气候行动）、14（水下生物），以及联合国海洋科学促进可持续发展十年计划。数百篇同行评议学术论文与高影响力报告均引用了SOCAT数据。SOCAT由科研社区主导的合成产品，是基于海洋原位无机碳测量数据的价值链中的关键环节，可为政策制定者在气候谈判中提供关于海洋二氧化碳吸收量的关键信息。精准掌握全球海洋二氧化碳吸收量及其（未来）变化的需求，使得持续资助原位表层海水二氧化碳观测及其合成工作成为当务之急。