Ramirez et al.,.xlsx

Here, we present a new paleo-rainfall reconstruction based on a speleothem d¹⁸O record from Colombia, which spans most of the last glacial cycle. Our results suggest that the strength and positioning of the Intertropical Convergence Zone over northern South America were more strongly affected by summer insolation at high northern latitudes than by local insolation during the last glacial cycle, resulting in an antiphased relationship with the climate in Cariaco Basin. New insight into how orbital forcing amplified or dampened Intertropical Convergence Zone precipitation during millennial-scale events, such as Greenland Stadials, Interstadials, and Heinrich events. During Greenland Stadial events, the Intertropical Convergence Zone was positioned close to the latitude of El Peñon, as expressed by very negative d¹⁸O values. Greenland Interstadial events, on the other hand, are marked by relatively high d¹⁸O values and reduced rainfall in the El Peñon record, suggesting a northward withdrawal of the Intertropical Convergence Zone, consistent with wetter conditions to the north at Cariaco. During some Heinrich Stadial events, and Heinrich Stadial 1 in particular, the Intertropical Convergence Zone must have been displaced away from its modern location near El Peñon, as conditions were very dry at both El Peñon and Cariaco.