Submesoscale Air-Sea Interactions as Revealed by SWOT

At midlatitudes, air-sea interactions have been documented in numerical models, in situ campaigns and satellite observations down to the ocean mesoscales. However little is known about scales of a few kilometers (the submesoscales). The new satellite mission Surface Water and Ocean Topography (SWOT) provides a global coverage of these scales by measuring sea surface height. Through the radar backscatter coefficient, it also provides surface wind speed at the same resolution. Here, we examine situations in the Gulf Stream and Kuroshio Extension regions where SWOT as well as scatterometer winds and sea surface temperature (SST) at kilometer scale were available. A good correspondence between winds from SWOT and scatterometer is found at the mesoscales. More importantly, the signature of SST anomalies is found in SWOT winds down to 10 km scales, confirming the effect of the ocean on the atmosphere at those scales. SWOT therefore opens new opportunities for the study of submesoscale air-sea interactions from space.