Influence of the tropics on the climate of the South Atlantic

Abstract

The climate of the tropical Atlantic is shown to undergo slow basinwide changes with time-scales of five years that include changes in surface winds, SST, and sea level. Further south in the Agulhas eddy corridor 35°S-25°S there are sea level fluctuations (superimposed on the dominant mesoscale eddies) on a similar timescale with amplitudes of 10 cm and with westward phase propagation of 4 cm s-1, giving rise to phase variations between the western and eastern sides of the basin. In the eastern basin sea level anomalies are accompanied by 0.5°C SST variations, while in the west the relationship is more complex. Here we explore the possibility that these subtropical sea level fluctuations are produced by the poleward propagation of the tropical sea level anomalies. Copyright 2006 by the American Geophysical Union.