Contrasting evolution of sea surface temperature in the Benguela upwelling system under natural and anthropogenic climate forcings: BENGUELA UPWELLING EVOLUTION

• Published in: Geophysical Research Letters
• Main Authors: Leduc, Guillaume, Herbert, Caren T, Blanz, Thomas, Martinez, Philippe, Schneider, Ralph
• Format: Article in Journal/Newspaper
• Language: English
• Published: Faculty of Science 2010
• Subjects: ice-age calibration sediments alkenone atlantic africa; Antarctic; The Antarctic; Antarc*; Antarctica; North Atlantic
• Online Access: http://hdl.handle.net/11427/34432; https://open.uct.ac.za/bitstream/11427/34432/1/LeducGuillaume_Contrasting_evo_2010.pdf

We present alkenone-derived Sea Surface Temperature (SST) records from three marine cores collected within the southern Benguela Upwelling System (BUS) spanning the last 3 ka. The SST evolution over the last 3 millennia is marked by aperiodic millennial-scale oscillations that broadly correspond to climatic anomalies identified over the North Atlantic region. The BUS SST data further suggest cooling and warming trends opposite to the temperature evolution in the Moroccan upwelling region and in Antarctica. In contrast, the last decades are marked by a cooling of unprecedented magnitude in both the Benguela and Moroccan upwelling systems, which is not observed in the Antarctic record. These contrasted responses in Atlantic upwelling systems triggered by natural and anthropogenic forcings shed light on how different climatic mechanisms are mediated by ocean-atmosphere interactions and transmitted to the geological records of past and present climate changes.