Millennial Variability in Intermediate Ocean Circulation and Indian Monsoonal Weathering Inputs During the Last Deglaciation and Holocene

• Published in: Geophysical Research Letters
• Main Authors: Yu, Zhaojie, Colin, Christophe, Wilson, David J., Bayon, Germain, Song, Zehua, Sepulcre, Sophie, Dapoigny, Arnaud, Li, Yuanlong, Wan, Shiming
• Other Authors: Géosciences Paris Saclay (GEOPS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), 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), COMS2019Q07; Natural Environment Research Council, NERC: NE/T011440/1; Agence Nationale de la Recherche, ANR: 6 024 04; National Natural Science Foundation of China, NSFC: 41806060, 91958107; Chinese Academy of Sciences, CAS: XDB42010402; Youth Innovation Promotion Association of the Chinese Academy of Sciences, YIPA CAS: 2020210; Polit National Laboratory for Marine Science and Technology, QNLM: MGQNLM‐TD201902, This study was supported by the Strategic Priority Research Program of Chinese Academy of Sciences (XDB42010402), the National Natural Science Foundation of China (91958107 and 41806060), Youth Innovation Promotion Association, CAS (2020210), Laboratory for Marine Geology, Qingdao Pilot National Laboratory for Marine Science and Technology (MGQNLM-TD201902), National Research Agency MONOPOL project (ANR 2011 Blanc SIMI 5–6 024 04), and the Key Deployment Project of CAS Centre for Ocean Mega-Science (COMS2019Q07). DJW is supported by a Natural Environment Research Council independent research fellowship (NE/T011440/1). We thank Jiaoyang Ruan, Jianghui Du and Xu Zhang for helpful discussions and several reviewers for their insightful comments., This study was supported by the Strategic Priority Research Program of Chinese Academy of Sciences (XDB42010402), the National Natural Science Foundation of China (91958107 and 41806060), Youth Innovation Promotion Association, CAS (2020210), Laboratory for Marine Geology, Qingdao Pilot National Laboratory for Marine Science and Technology (MGQNLM‐TD201902), National Research Agency MONOPOL project (ANR 2011 Blanc SIMI 5–6 024 04), and the Key Deployment Project of CAS Centre for Ocean Mega‐Science (COMS2019Q07). DJW is supported by a Natural Environment Research Council independent research fellowship (NE/T011440/1). We thank Jiaoyang Ruan, Jianghui Du and Xu Zhang for helpful discussions and several reviewers for their insightful comments., ANR-11-BS56-0024,MONOPOL,Paléo-variabilité de la mousson indienne(2011)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: Antarctic Intermediate Water; Indian Summer Monsoon; neodymium (Nd) isotope; [SDU]Sciences of the Universe [physics]; Antarctic; Southern Ocean; Indian; Antarc*
• Online Access: https://hal.science/hal-03888919; https://doi.org/10.1029/2022GL100003

International audience The relationship between ocean circulation and monsoon systems over orbital to sub-millennial timescales is a crucial but poorly constrained component of the climate system. Here, using foraminiferal and detrital neodymium (Nd) isotope records from the intermediate-depth northern Indian Ocean, we provide new evidence revealing that both monsoon-driven weathering inputs and water mass advection from the Southern Ocean influenced past seawater Nd isotope changes in this region. Our results suggest that Indian Summer Monsoon weakening coincided with enhanced northward Antarctic Intermediate Water (AAIW) advection during the last deglaciation, reflecting a strong interhemispheric coupling. In contrast, the Early Holocene was characterized by enhanced monsoon strength but persistently strong AAIW inflow, indicating a relationship in the opposite sense. These differing interhemispheric relationships indicate asynchronous changes in the global atmosphere—ocean—climate system, and may represent a previously unrecognized component of the ocean-atmosphere reorganization during the deglacial to Holocene transition.