Variability of the Brazil Current and its impacts on the South American climate during the last 30,000 years: assessing sea-surface temperatures via Mg/Ca analyses

Abstract

The Brazil Current (BC) represents the southern branch of the bifurcation of the South Equatorial Current that interacts with the eastern and southern Brazilian continental margins. The BC plays an important role in controlling the intensity of the South American Monsoon System that, in turn, is responsible for summer precipitation in a large sector of South America. Moreover, the BC is influenced by the Atlantic Meridional Overturning Circulation whose past oscillations generated marked global abrupt climatic changes. Presently, the few paleoceanographic records available from the western South Atlantic do not allow a detailed reconstruction of the changes that happened in the BC during the last glacial period. This research internship proposal aims at reconstructing the variability in sea-surface temperatures of the BC around 32°S from 19,000 until 33,000 years before the present based on Mg/Ca analyses in planktonic foraminiferal tests. Therefore, we will investigate a marine sediment core collected in the southern Brazilian continental margin, in a site under the influence of the BC. (AU)