Variability of the Brazil Current and South American climate during the last glacial cycle: assessing sea-surface temperatures via Mg/Ca analyses and pulses of terrigenous sediments via X-ray fluorescence analyses
The western boundary currents of the South Atlantic play a fundamental role in the distribution of energy between the hemispheres. The Brazil Current (BC), for instance, stores and redirects towards the mean latitudes of the Southern Hemisphere a significant portion of heat during periods of a weak Atlantic Meridional Overturning Circulation. Additionally, the BC influences the South Atlantic Converge Zone (SACZ), which is responsible for summer precipitation in a large sector of South America. The SACZ is also a crucial source of precipitation to the São Francisco River drainage basin, the largest drainage basin in eastern South America (ESA), whose response to millennial-scale climate events is poorly known. The data so far obtained under the PhD project of the candidate are very promising and will most probably provide a significant improvement on our understanding of millennial-scale changes in the BC and in the climate of ESA. The requested research internship aims at reconstructing (i) the variability in sea-surface temperatures of the BC, and (ii) changes in precipitation over the São Francisco River drainage basin through pulses of terrigenous sediments around 10.5°S for the last glacial cycle based on Mg/Ca analyses in planktonic foraminiferal tests and X-ray fluorescence analyses in bulk sediment samples, respectively. Therefore, we will investigate marine sediment cores M125-95-2/3 collected at a site under the influence of the BC and subject to the delivery of terrigenous sediments from the São Francisco River drainage basin.
News published in Agência FAPESP Newsletter about the scholarship: