Anomalies in the western boundary system of the tropical Atlantic ocean associated with the inter-ocean exchanges variability

Outputs of a numerical assimilation with the Hybrid Coordinate Ocean Model (1/12 degree resolution) in the South Atlantic from 1970-2010, forced my monthly NCEP wind data are assessed and used to study the variations of the Agulhas System and their impact into the tropical Atlantic ocean, focusing in the western boundary system. The assimilation represents well the large scale circulation in the South and tropical Atlantic. The 1/12 degree model resolves the mesoscale processes, with the South Atlantic having two important regions of high energy, the Brazil/Malvinas Confluence and the Agulhas Retroflection. Principally, the Agulhas system plays an important role in global climate, by its contribution to the “warm water route” of the thermohaline circulation. Results show an increase in the North Brazil Current (NBC) and decrease of the Brazil Current since the last decade (1990-2010), while that the transport of the Agulhas leakage increased. This study also reveals that the increase in the volumen transport of the NBC impact the latent heat flux and the precipitation in the Brazilian coast.