Sea Surface Salinity In Situ Data in the North Atlantic and Western Mediterranean Sea during Fall 2021

Sea Surface Salinity (SSS) values were obtained from in situ water samples collected at the surface and at a depth of 4.5 m in the North Atlantic and Western Mediterranean Sea during fall 2021. Sampling was conducted from the vessel St. Helena between 13 September and 3 October 2021, starting in Kangerlussuaq Fjord (Greenland) and ending in Cagliari (Sardinia, Italy), covering approximately 4,000 nautical miles. Water samples were collected at regular intervals, with a sampling frequency of 4–6 hours. Fieldwork was carried out as part of the Italian PNRA SWIMMING project, hosted onboard by the Extreme-E racing series organization during the paddock transfer from Greenland to Sardinia. Laboratory analyses were performed at CNR-ISMAR La Spezia (Italy) using an Autosal Portable Salinometer. The instrument was carefully calibrated with standard salinity solutions suitable for the different oceanic regions sampled (Greenland, Atlantic Ocean, and Mediterranean Sea). Each salinity measurement was repeated three times per water sample to ensure data accuracy. // Column 1 : ID (station number)// Column 2 : Date (day/mon/yr)// Column 3 : Time (hh:mm)// Column 4 : Latitude [degrees_north]// Column 5 : Longitude [degrees_east]// Column 6 : In situ Sea surface Temperature [°C] // Column 7 : Salinometer bath Temperature [°C] // Column 8 : Salinometer Salinity [psu] // Column 9 : Depth of in situ water samples collection (surface / -4.5 m)