CoAuthors

Boris Dewitte (LEGOS, France); Abderrahim Bentamy (LOPS, France); Frédéric Frappart (LEGOS, France)

The near-shore surface mesoscale atmospheric circulation in the upwelling systems off Peru and Chile is influential on the Sea Surface Temperature through Ekman transport and pumping. There has been a debate whether or not the so-called “wind drop-off”, that is a shoreward decrease of the surfacewind speed near the coast, can act as an effective forcing of upwelling through Ekman pumping. Although the wind drop-off has been simulated by high-resolution atmospheric models, it has not been well documented due to uncertainties in the scatterometry-derived wind estimates associated with land contamination. A preivous study used along-track altimetry-derived surface wind speed data from ENVISAT, Jason-1, Jason-2, and SARAL satellites, to document the spatial variability of the mean wind drop-off near the coast as estimated from the inversion of the radar backscattering coefficient. In this study, we analyzed the performances of the recently launched Jason-3 and Sentinel-3A altimetry missions to analyze the surface wind speed in the Peru-Chile Equatorial boundary upwelling system.