Atlantic Ocean circulation changes preceded millennial tropical South America rainfall events during the last glacial

• DOI: 10.1002/2014gl062512
• Publication Date: 2015-01-06T04:16:19Z
• Authors: Pierre Burckel; Claire Waelbroeck; Jeanne Marie Gher...; Sylvain Pichat; Helge Arz; Joerg Lippold; Trond Dokken; François Thil
• Keywords: Stadial; Tropical Atlantic

Abstract During the last glacial period, Greenland's climate shifted between cold (stadial) and warm (interstadial) phases that were accompanied by ocean circulation changes characterized reduced Atlantic Meridional Overturning Circulation (AMOC) during stadials. Here we present new data from western tropical demonstrating AMOC slowdowns preceded some of large South American rainfall events took place Based on 231 Pa/ 230 Th Ti/Ca measurements in same sediment core, determine started to slowdown 1420 ± 250 690 180 (1 σ ) years before onset two precipitation associated with Heinrich Our results bring unprecedented evidence could be at origin observed America In addition, propose a mechanism explaining differences extent timing shorter longer