Determination of millennial-scale climate variability based on alkenones in the western Atlantic Ocean ...

• Main Authors: Jaeschke, Andrea, Rühlemann, Carsten, Arz, Helge Wolfgang, Heil, Gerrit M N, Lohmann, Gerrit
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2007
• Subjects: Gravity corer Kiel type; M34/4; Meteor 1986; Geosciences, University of Bremen GeoB; Antarc*; Antarctic; North Atlantic
• Online Access: https://dx.doi.org/10.1594/pangaea.667499; https://doi.pangaea.de/10.1594/PANGAEA.667499

High-resolution records of alkenone-derived sea surface temperatures and elemental Ti/Ca ratios from a sediment core retrieved off northeastern Brazil (4° S) reveal short-term climate variability throughout the past 63,000 a. Large pulses of terrigenous sediment discharge, caused by increased precipitation in the Brazilian hinterland, coincide with Heinrich events and the Younger Dryas period. Terrigenous input maxima related to Heinrich events H6–H2 are characterized by rapid cooling of surface water ranging between 0.5 and 2° C. This signature is consistent with a climate model experiment where a reduction of the Atlantic meridional overturning circulation (AMOC) and related North Atlantic cooling causes intensification of NE trade winds and a southward movement of the Intertropical Convergence Zone, resulting in enhanced precipitation off northeastern Brazil. During deglaciation the surface temperature evolution at the core site predominantly followed the Antarctic warming trend, including a cooling, ... : Supplement to: Jaeschke, Andrea; Rühlemann, Carsten; Arz, Helge Wolfgang; Heil, Gerrit M N; Lohmann, Gerrit (2007): Coupling of millennial-scale changes in sea surface temperature and precipitation off northeastern Brazil with high-latitude climate shifts during the last glacial period. Paleoceanography, 22(4), PA4206 ...