15 páginas, 4 figuras, 4 tablas. ; Regional air-sea fluxes, ocean transport, and storage of anthropogenic carbon (Canth) are quantified. Observation-based Canth data from the ocean interior are assimilated into the Bern3D dynamic ocean model using an Ensemble Kalman Filter. Global uptake of Canth is estimated to be 131 ± 18 GtC over the period 1770 to 2000. Uncertainties from systematic biases in the reconstruction of Canth are assessed by assimilating data from four global and six Atlantic reconstructions and found to be comparable or larger than uncertainties from ocean transport. Aggregated fluxes for the southern high-latitude, tropical and midlatitude, and northern high-latitude ocean agree within 0.11 GtC a(-1) for the two reconstructions with the highest skill score, whereas regional uptake rates are up to a factor of three different. Results indicate that uptake and regional partitioning of anthropogenic carbon in the Southern Ocean remains uncertain. ; This study was financially supported by the European Union through the Integrated Project CarboOcean (511106-2), the Swiss National Science Foundation, and the Swiss Staatsekretariat für Bildung und Forschung (C07.0068; COST Action 735). ; Peer reviewed
This is the final version of the article. Available from the publisher via the DOI in this record. ; The Surface Ocean CO2 Atlas (SOCAT) is a synthesis of quality-controlled fCO2 (fugacity of carbon dioxide) values for the global surface oceans and coastal seas with regular updates. Version 3 of SOCAT has 14.7 million fCO2 values from 3646 data sets covering the years 1957 to 2014. This latest version has an additional 4.6 million fCO2 values relative to version 2 and extends the record from 2011 to 2014. Version 3 also significantly increases the data availability for 2005 to 2013. SOCAT has an average of approximately 1.2 million surface water fCO2 values per year for the years 2006 to 2012. Quality and documentation of the data has improved. A new feature is the data set quality control (QC) flag of E for data from alternative sensors and platforms. The accuracy of surface water fCO2 has been defined for all data set QC flags. Automated range checking has been carried out for all data sets during their upload into SOCAT. The upgrade of the interactive Data Set Viewer (previously known as the Cruise Data Viewer) allows better interrogation of the SOCAT data collection and rapid creation of high-quality figures for scientific presentations. Automated data upload has been launched for version 4 and will enable more frequent SOCAT releases in the future. Highprofile scientific applications of SOCAT include quantification of the ocean sink for atmospheric carbon dioxide and its long-term variation, detection of ocean acidification, as well as evaluation of coupled-climate and ocean-only biogeochemical models. Users of SOCAT data products are urged to acknowledge the contribution of data providers, as stated in the SOCAT Fair Data Use Statement. This ESSD (Earth System Science Data) "living data" publication documents the methods and data sets used for the assembly of this new version of the SOCAT data collection and compares these with those used for earlier versions of the data collection (Pfeil et al., 2013; Sabine et al., 2013; Bakker et al., 2014). Individual data set files, included in the synthesis product, can be downloaded here: doi:10.1594/PANGAEA.849770. The gridded products are available here: doi:10.3334/CDIAC/OTG.SOCAT-V3-GRID. ; Research vessel Tiglax in Columbia Bay, Alaska, is shown on the website for SOCAT version 3. The Columbia Glacier can be seen at the head of the bay, as well as calved ice from the glacier. The photo was taken by Wiley Evans. Pete Brown (National Oceanography Centre Southampton, UK) designed the SOCAT logo. IOCCP (via a US National Science Foundation grant (OCE-124 3377) to the Scientific Committee on Oceanic Research), IOC-UNESCO (International Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization), SOLAS and IMBER provided travel and meeting support. Funding was received from the University of East Anglia (UK), the Bjerknes Centre for Climate Research (Norway), the Geophysical Institute at the University of Bergen (Norway) and the University of Washington (US). The US National Oceanic and Atmospheric Administration (NOAA) made important financial contributions via the Climate Observation Division of the Climate Program Office, the NOAA Ocean Acidification Program, the NOAA Pacific Marine Environmental Laboratory (PMEL), the NOAA Atlantic Oceanographic and Meteorological Laboratory (AOML) and the NOAA Earth System Research Laboratory. Funding was also received from Oak Ridge National Laboratory (US), PANGAEA® Data Publisher for Earth and Environmental Science (Germany), the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (Germany), the Antarctic Climate and Ecosystems Cooperative Research Centre (Australia), the National Institute for Environmental Studies (Japan) and Uni Research (Norway). Research projects making SOCAT possible included the European Union projects CarboChange (FP7 264879), GEOCARBON (FP7 283080) and AtlantOS (633211), the UK Ocean Acidification Research Programme (NE/H017046/1; funded by the Natural Environment Research Council (NERC) and the Departments for Energy and Climate Change and for Environment, Food and Rural Affairs (Defra)) and the UK Shelf Sea Biogeochemistry Blue Carbon project (NE/K00168X/1; funded by NERC and Defra). Numerous government and funding agencies financially supported SOCAT, notably the Australian International Marine Observing System, the U.S. Geological Survey, the National Aeronautics and Space Administration (NASA) (US), the European Space Agency, the German Federal Ministry of Education and Research (BMBF projects 01LK1224J, 01LK1101C, 01LK1101E, ICOS-D), the Japanese Ministry of the Environment, the Royal Society of New Zealand via the New Zealand–Germany Science and Technology Programme, the Norwegian Research Council (SNACS, 229752), the Swedish Research Council (project 2004-4034) and the Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (Formas, project 2004- 797). This is PMEL contribution number 4441. Finally, we thank the two anonymous reviewers for their thoughtful, constructive and insightful reviews
