A REGIONAL STUDY OF THE BRAZILIAN SHELF/SLOPE CIRCULATION (13◦-31◦S) USING CLIMATOLOGICAL OPEN BOUNDARIES

. The oceanic features in the eastern and southeastern Brazilian shelf/slope between 13◦-31◦S are investigated using ROMS (Regional Ocean Model System). The model was integrated for 9 years and it was forced with: i) 6-hourly synoptic atmospheric data from NCEP; ii) initial and boundary conditions from OCCAM (Ocean Climate Circulation Advanced Modelling) monthly mean climatology and iii) tidal forcing from TPXO 7.1 global data set. The model results were compared with observations, which consisted in thermodynamic MDL (Mixed Layer Depth) climatology, satellite data, measurements from tide gauges along the shelf and currents measurements values from literature. The simulated currents represented the BC (Brazil Current)-IWBC (Intermediate Western Boundary Current) System. The BC-IWBC system at 22◦S cross-shelf section represents our simulation capability of reproducing the western boundary currents, it showed poleward BC and a opposing IWBC. At this section, the BC velocity core is in 50 m with 0.41 m.s− 1 and the IWBC core around 800 m with 0.15 m.s− 1. Keywords : Western South Atlantic, ROMS, Western Boundary Currents. RESUMO . A circulacao oceânica na regiao da plataforma/talude do Brasil de 13◦-31◦S e investigada utilizando o modelo ROMS (Regional Ocean Model System). O modelo foi integrado por 9 anos e forcado com: i) dados atmosfericos sinotico a cada 6 horas do NCEP; ii) condicoes iniciais e laterais provenientes da climatologia mensal do modelo global OCCAM (Ocean Climate Circulation Advanced Modelling) e iii) forcamento de mare do modelo global TPXO 7.1. Os resultados do modelo foram comparados com observacoes, estas consistem em dados da profundidade da camada de mistura climatologica, dados de satelite, medicoes de maregrafos ao longo da plataforma e valores de medicoes de correntes disponiveis na literatura. As correntes simuladas representaram o sistema da CB (Corrente do Brasil)-CCI (Corrente de Contorno Intermediaria). O sistema CB-CCI na secao normal a costa em 22◦S representou a capacidade de simulacao das correntes de contorno oeste, mostrando a inversao de direcao das duas correntes. Nesta secao, o nucleo de velocidade da CB em 50 m apresentou valores de 0,41 m.s− 1 e o nucleo da CCI em 800 m apresentou velocidade de 0,15 m.s− 1. Palavras-chave: Sudoeste do Atlântico, ROMS, Correntes de Contorno Oeste.