Last glacial atmospheric CO2 decline due to widespread Pacific deep-water expansion

Yu, J. and Menviel, L. and Jin, Z. D. and Anderson, R. F. and Jian, Z. and Piotrowski, A. M. and Ma, X. and Rohling, E. J. and Zhang, F. and Marino, G. and McManus, J. F. (2020) Last glacial atmospheric CO2 decline due to widespread Pacific deep-water expansion. Nature Geoscience, 13 (9). pp. 628-633. ISSN 1752-0894 DOI https://doi.org/10.1038/s41561-020-0610-5

[img] Text
Yu+et+al+-+2020.pdf - Accepted Version

Download (744kB)
[img] Text
41561_2020_610_MOESM1_ESM.xlsx - Supplemental Material

Download (119kB)
Official URL: https://rdcu.be/b6YFZ

Abstract

Ocean circulation critically affects the global climate and atmospheric carbon dioxide through redistribution of heat and carbon in the Earth system. Despite intensive research, the nature of past ocean circulation changes remains elusive. Here we present deep-water carbonate ion concentration reconstructions for widely distributed locations in the Atlantic Ocean, where low carbonate ion concentrations indicate carbon-rich waters. These data show a low-carbonate-ion water mass that extended northward up to about 20° S in the South Atlantic at 3–4 km depth during the Last Glacial Maximum. In combination with radiocarbon ages, neodymium isotopes and carbon isotopes, we conclude that this low-carbonate-ion signal reflects a widespread expansion of carbon-rich Pacific deep waters into the South Atlantic, revealing a glacial deep Atlantic circulation scheme different than commonly considered. Comparison of high-resolution carbonate ion records from different water depths in the South Atlantic indicates that this Pacific deep-water expansion developed from approximately 38,000 to 28,000 years ago. We infer that its associated carbon sequestration may have contributed critically to the contemporaneous decline in atmospheric carbon dioxide, thereby helping to initiate the glacial maximum.

Item Type: Article
Uncontrolled Keywords: 2020AREP; IA76
Subjects: 01 - Climate Change and Earth-Ocean Atmosphere Systems
Divisions: 01 - Climate Change and Earth-Ocean Atmosphere Systems
08 - Green Open Access
Journal or Publication Title: Nature Geoscience
Volume: 13
Page Range: pp. 628-633
Identification Number: https://doi.org/10.1038/s41561-020-0610-5
Depositing User: Sarah Humbert
Date Deposited: 09 Sep 2020 16:54
Last Modified: 20 Feb 2021 01:01
URI: http://eprints.esc.cam.ac.uk/id/eprint/4871

Actions (login required)

View Item View Item

About cookies