Role of Asian summer monsoon subsystems in the inter-hemispheric progression of deglaciation

Nilsson-Kerr, K.; Anand, P.; Sexton, P.F.; Leng, M.J. ORCID: https://orcid.org/0000-0003-1115-5166; Misra, S.; Clemens, S.C.; Hammond, S.J.. 2019 Role of Asian summer monsoon subsystems in the inter-hemispheric progression of deglaciation. Nature Geoscience, 12. 290-295. https://doi.org/10.1038/s41561-019-0319-5

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Official URL: http://dx.doi.org/10.1038/s41561-019-0319-5

Abstract/Summary

The responses of Asian monsoon subsystems to both hemispheric climate forcing and external orbital forcing are currently issues of vigorous debate. The Indian summer monsoon is the dominant monsoon subsystem in terms of energy flux, constituting one of Earth’s most dynamic expressions of ocean–atmosphere interactions. Yet, the Indian summer monsoon is grossly under-represented in Asian monsoon palaeoclimate records. Here, we present high-resolution records of Indian summer monsoon-induced rainfall and fluvial runoff recovered in a sediment core from the Bay of Bengal across Termination II, 139–127 thousand years ago, including coupled measurements of the oxygen isotopic composition and Mg/Ca, Mn/Ca, Nd/Ca and U/Ca ratios in surface-ocean-dwelling foraminifera. Our data reveal a millennial-scale transient strengthening of the Asian monsoon that punctuates Termination II associated with an oscillation of the bipolar seesaw. The progression of deglacial warming across Termination II emerges first in the Southern Hemisphere, then the tropics in tandem with Indian summer monsoon strengthening, and finally the Northern Hemisphere. We therefore suggest that the Indian summer monsoon was a conduit for conveying Southern Hemisphere latent heat northwards, thereby promoting subsequent Northern Hemisphere deglaciation.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1038/s41561-019-0319-5
ISSN:	1752-0894
Date made live:	22 Mar 2019 16:00 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/522635

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1038/s41561-019-0319-5

ISSN:

1752-0894

Date made live:

22 Mar 2019 16:00 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/522635