Ocean-atmosphere in situ observations at the Brazil-Malvinas Confluence region

Abstract

This paper presents a description of marine atmospheric boundary layer (MABL) and oceanic boundary layer(OBL)interactions at the Brazil-Malvinas Confluence. Although this region is known as one of the most energetic zones of the World Ocean, very few studies have addressed the mechanisms of OA interaction there. Based upon novel, direct in situ simultaneous OA observations, our results show that the OBL-MABL exchanges are closely correlated with the sea surface temperature (SST) field. The heat fluxes range from 110 W.m2 over warm waters down to 18 W.m2 over cold waters. Higher heat fluxes and air-sea temperature differences are associated with stronger near-surface winds. This suggests that the MABL is modulated at the synoptic temporal and spatial scale by the strong surface thermal gradients between the (warm) Brazil and the (cold) Malvinas (Falklands) currents.