We present here sea surface salinity (SSS) and temperature (SST) datacollected on board the S.A. Agulhas-I and S.A. Agulhas-IIresearch vessels, in the framework of the South African National AntarcticProgramme (SANAP). Onboard Sea-Bird thermosalinographs were regularlycalibrated and continuously monitored in-between cruises, and no appreciablesensor drift emerged. Water samples were taken on a daily basis and lateranalyzed with a Portasal salinometer; some CTD measurements collected alongthe cruises were used to validate the data. No systematic differencesappeared after a rigorous quality control on continuous data. Results showthat salinity measurement error was a few hundredths of a unit on thepractical salinity scale. Quality control included several steps, among whichan automatic detection of unreliable values through selected thresholdcriteria and an attribution of quality flags based on multiple criteria,i.e., analysis of information included in the cruise reports, detection ofinsufficient flow and/or presence of air bubbles and ice crystals in theseawater pipe, visual inspection of individual campaigns, and ex post checkof sea ice maps for confirming ice field locations. This data processing ledus to discard about 36 % of acquired observations, while reliable datashowed an excellent agreement with several independent SSS products.Nevertheless, a sea ice flag has been included for identifying valid datawhich could have been affected by scattered sea ice contamination. In ouropinion, this dataset, available through an unrestricted repository athttps://doi.org/10.7289/V56M3545, contributes to improving theknowledge of surface water features in one of the most important regions forglobal climate. The dataset will be highly valuable for studies focusing onclimate variability in the Atlantic sector of the Southern Ocean, especiallyacross the Antarctic Circumpolar Current and its fronts. Furthermore, weexpect that the collected SSS data will represent a valuable tool for thecalibration and validation of recent satellite observations provided by SMOSand Aquarius missions.
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