Antarctic Intermediate Water penetration into the Northern Indian Ocean during the last deglaciation

• Published in: Earth and Planetary Science Letters
• Main Authors: Yu, Zhaojie, Colin, Christophe, Ma, Ruifang, Meynadier, Laure, Wan, Shiming, Wu, Qiong, Kallel, Nejib, Sepulcre, Sophie, Dapoigny, Arnaud, Bassinot, Frank
• Other Authors: Géosciences Paris Sud (GEOPS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Key Laboratory of Marine Geology and Environment China, Institute of Oceanology China, Center for Ocean Mega-Science, Chinese Academy of Sciences, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), College of Oceanography, Hohai University, Unité GEOGLOB, Faculté des Sciences de Sfax, Université de Sfax - University of Sfax-Université de Sfax - University of Sfax, 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), Géochrononologie Traceurs Archéométrie (GEOTRAC), 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), Paléocéanographie (PALEOCEAN), This work was supported by the National Natural Science Foundation of China (41622603 and 41576034), National Programme on Global Change and Air–Sea Interaction (GASI-GEOGE-03), Innovation Project (2016ASKJ13) and Aoshan Talents programme (2017ASTCP-ES01) of Qingdao National Laboratory for Marine Science and Technology and CAS Interdisciplinary Innovation Team, Open Fund of the Key Laboratory of Marine Geology and Environment, Chinese Academy of Sciences (No. MGE2018KG01). Z. Yu acknowledges the China Scholarship Council for providing funding for his study in France. This study was supported by the Labex L-IPSL and the MONOPOL projects, which are funded by the ANR (grant nos. ANR-10-LABX-0018 and ANR 2011 Blanc SIMI 5-6 024 04), ANR-10-LABX-0018,L-IPSL,LabEx Institut Pierre Simon Laplace (IPSL): Understand climate and anticipate future changes(2010), ANR-11-BS56-0024,MONOPOL,Paléo-variabilité de la mousson indienne(2011)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: Panoply; [SDU]Sciences of the Universe [physics]; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; Antarctic; Indian; Pacific; Southern Ocean; Antarc*; Planktonic foraminifera
• Online Access: https://hal.science/hal-01897030; https://doi.org/10.1016/j.epsl.2018.08.006

International audience The two-stage increase in atmospheric carbon dioxide (CO2), and the associated decrease in radiocarbon (14C) during the last deglaciation, are thought to have been linked to enhanced Southern Ocean upwelling and the rapid release of sequestered 14C-depleted CO2. Antarctic Intermediate Water (AAIW), originating from the Southern Ocean, reflects variations in the Southern Ocean and, crucially, mirrors the chemical signature of upwelling deep water. However, the penetration of AAIW into the Northern Indian Ocean and its relationship with deglacial climate changes have not been thoroughly elucidated to date. Here, we present the neodymium isotopic composition () of mixed planktonic foraminifera from core MD77-176 from an intermediate depth in the Northern Indian Ocean to reconstruct the past evolution of intermediate water during deglaciation. The record in the Northern Indian Ocean displays two pulse-like shifts towards more radiogenic Southern Ocean values during the deglaciation, and these shifts coincide with excursions in and records in the Pacific and Atlantic Oceans. These results suggest invasion of AAIW into the Northern Hemisphere oceans associated with enhanced Southern Ocean ventilation during deglaciation. Our new record strongly supports the close linkage of AAIW propagation and atmospheric CO2 rise through Southern Ocean ventilation during deglaciation.