Ocean-atmosphere interactions over the western South Atlantic during Heinrich stadials

Slowdowns of the Atlantic meridional overturning circulation during Heinrich stadials (HS) caused reductions in cross-equatorial heat transport, southward shifts of the Intertropical Convergence Zone and intensification of precipitation over eastern tropical South America. While these changes are well described, the associated spatial sea surface temperature (SST) patterns are still unclear. Here, we analyze proxy data to assess changes in ocean-atmosphere interactions during HS over the western South Atlantic. Our SST proxy records show contrasting patterns between the tropical (warming) and the subtropical (no change) western South Atlantic during HS. We propose that the distinct SST behavior in the subtropics was associated with the cloud cover effect of the South Atlantic Convergence Zone over the upper ocean. •Contrasting changes in sea surface temperature during Heinrich stadials between the tropical and the subtropical Atlantic•Increase in sea surface temperature during Heinrich stadials in the western equatorial Atlantic•Intensification of the South Atlantic Convergence Zone cloud cover causes regional ocean surface cooling