The influence of the Brazil and Malvinas Currents on the Southwestern Atlantic Shelf Circulation

MATANO, R. P.; PALMA, E. D.; PIOLA, A. R.

OCEAN SCIENCE (OS)

COPERNICUS PUBLICATIONS

Lugar: Gottingen; Año: 2010 vol. 6 p. 983 - 995

1812-0784

The oceanic circulation over the southwesternAtlantic shelf is influenced by large tidal amplitudes, substantialfreshwater discharges, high wind speeds and – mostimportantly – by its proximity to two of the largest westernboundary currents of the world ocean: the Brazil and Malvinascurrents. This review article aims to discriminate thedynamical processes controlling the interaction between thisextensive shelf region and the deep-ocean. The discussion isfocused on two broad regions: the South Brazil Bight to thenorth, and Patagonia to the south. The exchanges betweenthe Brazil Current and the South Brazil Bight are characterizedby the intermittent development of eddies and meandersof the Brazil Current at the shelfbreak. However, it is arguedthat this is not the only – nor the most important – influenceof the Brazil Current on the shelf. Numerical simulationsshow that the thermohaline structure of the South BrazilBight can be entirely ascribed to steady state, bottom boundarylayer interactions between the shelf and the Brazil Current.The Malvinas Current does not show the developmentof eddies and meanders, but its influence on the Patagonianshelf is not less important. Models and observations indicatethat the Malvinas Current not only controls the shelfbreakdynamics and cross-shelf exchanges but also influences thecirculation in the shelf’s interior.