Efeitos do aumento da tensÃo de cisalhamento do vento no clima do hemisfÉrio sul obtido do modelo acoplado speedo

Abstract

Studies have suggested intensifcation and shift of the wind stress maximum towards the south in the Southern Ocean due to wind intensifcation in extratropical latitudes in the Southern Hemisphere. Considering these evidences, the objective of this study is to investigate the impacts in atmospheric and oceanic circulation due to the increasing wind stress by 50% in the equatorial region and in the extratropical Southern Hemisphere region. Specifcally, changes in the Atlantic Dipole and Antarctic Oscillation are analyzed. For this purpose, a coupled climate model of intermediate complexity (SPEEDO) is employed. The results show that the wind stress intensifcation in the equatorial region causes a decrease in sea surface temperature in the tropical region, due to increased upwelling. This causes changes in Atlantic Dipole and enhanced precipitation over Brazilian northeast. Moreover, the wind stress intensifcation in the extratropical Southern Hemisphere region induces an increase in sea surface temperature and air temperature in high latitudes of the Southern Hemisphere, and a reduction in the Antarctic sea ice thickness, favoring a weakening of positive Antarctic Oscillation phase.