Changes in latitudinal sea surface temperature gradients along the Southern Chilean margin since the last glacial

• Published in: Quaternary Science Reviews
• Main Authors: Haddam, Naoufel Abdeldjalyl, Siani, Giuseppe, Michel, Elisabeth, Kaiser, Jérôme, Lamy, Frank, Duchamp-Alphonse, Stéphanie, Hefter, Jens, Braconnot, Pascale, Dewilde, Fabien, Isguder, Gulay, Tisnerat-Laborde, Nadine, Thil, François, Durand, Nicolas, Kissel, Catherine
• Other Authors: Géosciences Paris Sud (GEOPS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Paléocéanographie (PALEOCEAN), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Modelling the Earth Response to Multiple Anthropogenic Interactions and Dynamics (MERMAID), Géochrononologie Traceurs Archéométrie (GEOTRAC), Laboratoire de mesure du carbone 14 (LMC14 - UMS 2572), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Radioprotection et de Sûreté Nucléaire (IRSN)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS), Climat et Magnétisme (CLIMAG)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; Antarctic; Pacific; Antarc*; Ice Sheet
• Online Access: https://hal.science/hal-01890530; https://doi.org/10.1016/j.quascirev.2018.06.023

International audience The comparison between different climate model simulations of water hosing experiments under glacial conditions points toward diverging responses in Sea Surface Temperature changes (SST) especially in the Southeast Pacific (SEP). This suggests that reconstituting the latitudinal SST gradient in the SEP is a critical parameter for a better understanding of the mechanisms behind the abrupt climatic events since the last glacial period. Here we present, high-resolution records of SST, using planktonic foraminiferal assemblages and alkenone temperature reconstructions and stable oxygen and carbon isotopes from three deep-sea sediment cores along a latitudinal transect off the southern Chilean coast. This allowed us to reconstruct the variations of the latitudinal SST gradient and the Subtropical Front movements in the SEP. The SST results suggest a clear Antarctic timing consistent with the bipolar seesaw control, especially during the late glacial and the deglaciation. Our records do not suggest a complete oceanic heat transfer signal, highlighting the implication of an atmospheric component in the heat transfers between the two hemispheres, controlled by the latitudinal movements of the intertropical convergence zone in the Atlantic and the associated weaker South Pacific westerly split jet. Furthermore, our records indicate variable conditions during the Holocene, and also emphasize the influence of local fresh water inputs from the Patagonian ice sheet and/or precipitation on the SST fresh water input estimates along the Chilean margin (North and South of 49 degrees S) from the onset of the deglaciation until 8 kyr cal. BP. (C) 2018 Elsevier Ltd. All rights reserved.