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

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 pr...

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Bibliographic Details
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
Format: Report
Language:English
Published: AMER GEOPHYSICAL UNION 2022
Subjects:
neodymium (Nd) isotope
Indian Summer Monsoon
Antarctic Intermediate Water
Geology
Geosciences
Multidisciplinary
Antarc*
Antarctic
Southern Ocean
Online Access:http://ir.qdio.ac.cn/handle/337002/180219
http://ir.qdio.ac.cn/handle/337002/180220
https://doi.org/10.1029/2022GL100003
Description
Summary: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.

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