Análise espacial e temporal dos centros de ressurgência e de suas forçantes na região sudeste brasileira

Abstract

This work aims to investigate the interannual variability of upwelling in the Southeast Brazilian region, where it was found that atmospheric drivers alone is not sufficient to explain the interannual variations of the South Atlantic Central Water (SACW) upwelling. Ten years of results from the LSE24 hydrodynamic database were used, an oceanic reanalysis developed by the Physical Oceanography Laboratory - LOF/COPPE of UFRJ, employing simulations with the HYCOM model, within the scope of the REMO - Oceanographic Modeling and Observation Network. EOF (Empirical Orthogonal Functions) analysis of the circulation indicates that the variation in the intensity of the Brazil Current flow over the continental shelf plays an important role as a driving factor of the upwelling in the Southeast region as whole. Quantification and analysis of ekman transport in the surface layer, due to wind drive, and in the bottom layer, due to current intrusion on the shelf, show that, for the Cabo Frio region, the interannual variability of upwelling is modulated by the variation in the intensity of the Brazil Current on the shelf. However, in the Cabo de São Tomé region, in addition to these driving factors, the availability of the South Atlantic Central Water (SACW) on the shelf shows to be relevant to the interannual variability of upwelling.