C-SWOT2023: a Mediterranean intensive field experiment in the framework of the SWOT fast sampling phase

The field experiment C-SWOT-2023 was carried out in North-Western Mediterranean Sea and aimed to support the new-generation SWOT altimeter (NASA/CNES) calibration and validation during its fast sampling phase. The daily overflight of the satellite between Marseille and Menorca was the opportunity to revisit the main aspects of the ocean circulation in the North-Western Mediterranean sub-basin such as the North Current, the Balearic Front or the eddy soup in the winter convection area.  The originality of the field experiment lies in the deployment of two research vessels (the R/V Thetys II for IFREMER and the R/V Atalante for the SHOM) that sailed along together to explore statistics of the surface ocean dynamics (vorticity, strain, divergence) that are seldomly accessible in fine scale observations. High resolution transects recording velocities, temperature and salinity in the first four hundred meters under the SWOT swaths were performed in order to disentangle the geostrophic and the ageostrophic part of the circulation. Dozens of drifting buoys have been dropped to assess the lagrangian aspect of the dynamics. A short overview of the 3D observations dataset will be proposed before focusing on the comparison between the dynamics experienced in situ and those observed remotely by SWOT.