The French Sea Surface Salinity Observation Service : Global Observations from Ships of Opportunity

Sea Surface Salinity (SSS) is an essential climate variable that requires long term in situ observation. In this objective, the French SSS Observation Service (SSS-OS) manages a network of ships of opportunity equipped with thermosalinographs (TSG). The network is global though more concentrated in the North Atlantic and tropical Pacific ocean, where it was initiated more than 50 years ago. The acquisition system is autonomous with real time transmission and is regularly serviced at harbor calls. There are distinct real time, near real time and delayed time processing chains. Real time processing includes automatic alerts in case data are outside of climatic limits, to detect potential instrument problems, and produces graphical monitoring tools. Delayed time processing relies on a dedicated software to attribute data quality flags by visual inspection, and correct TSG time series by comparison with daily water samples. The near real time processing relies on automatic algorithms to attribute preliminary quality flags and corrections based on comparison with climatological data and colocated Argo data, respectively. The SSS-OS (near) real time data feed the Coriolis operational oceanography database, while the research-quality delayed time data can be extracted for selected time and geographical ranges through a user-friendly web interface. Delayed time data are also combined with other SSS data sources to produce gridded files for the Pacific and Atlantic oceans. Research conducted with these data includes studies where in situ SSS is used for calibration/validation of models, coral proxies or satellite data, as well as observation-based process-oriented and climate studies from regional to global scale.