hide
Free keywords:
-
Abstract:
The surface wind variability is a key factor inducing changes in the circulation, biogeochemistry, and ecosystems over continental shelves. Wind-induced changes in sea surface height modulate the cross-shore pressure gradient and lead to changes in the along-shore geostrophic flow. In the western South Atlantic continental shelf north of about 42 ºS, the wind variability modulates the northward advection of cold, low-salinity, high-nutrient waters. We analyze the impact of surface meridional wind variations from the ERA5 reanalysis on sea satellite-derived sea surface temperature (SST) and sea level anomaly (SLA) from microwave optimum interpolation SST and AVISO/Copernicus, respectively over the South Atlantic continental shelf between 35 and 55 °S in the past 20 years. The results indicate that the meridional wind variations modulate the temperature changes over the continental shelf at synoptic and interannual scales. South of about 50 ºS other processes appear to control the SLA variations. At the interannual scale, a significant correlation (r ∼ 0.64) is observed between the first EOF of the meridional wind anomalies and the second EOF of sea level anomalies, respectively. This mode of SLA variability shows a meridional dipole pattern on the Patagonian shelf between 35 and 55 °S. Our results suggest that future variations in wind patterns may have a significant impact on the circulation and the water mass properties over the western South Atlantic shelf.
