Age model determination, stable oxygen isotope record, and XRF ln(Ti/Ca) and ln(Fe/K) of piston core M125-95-3

It is the first core off eastern South America and the southernmost from the Atlantic continental margin of South America that unequivocally records HS-related positive precipitation anomalies. Based on our new data, model results and the compilation of available marine records, we propose a new mechanism for the positive precipitation anomalies over tropical South America during HS. The new mechanism involves austral summer precipitation increases only over eastern South America while the rest of tropical South America experienced precipitation increases during the winter, challenging the widely held assumption of a strengthened monsoon.

South American precipitation changes were triggered by dynamic and thermodynamic processes including a stronger moisture supply from the equatorial North Atlantic (tropical South Atlantic) in austral winter (summer).