Last glacial atmospheric CO2 decline due to widespread Pacific deep-water expansion
Last glacial atmospheric CO2 decline due to widespread Pacific deep-water expansion
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.
628-633
Yu, J.
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Menviel, L.
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Jin, Z. D.
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Anderson, R. F.
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Jian, Z.
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Piotrowski, A. M.
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Ma, X.
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Rohling, E. J.
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Zhang, F.
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Marino, G.
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Mcmanus, J. F.
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Yu, J.
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Menviel, L.
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Jin, Z. D.
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Anderson, R. F.
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Jian, Z.
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Piotrowski, A. M.
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Ma, X.
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Rohling, E. J.
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Zhang, F.
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Marino, G.
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Mcmanus, J. F.
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Yu, J., Menviel, L., Jin, Z. D., Anderson, R. F., Jian, Z., Piotrowski, A. M., Ma, X., Rohling, E. J., Zhang, F., Marino, G. and Mcmanus, J. F.
(2020)
Last glacial atmospheric CO2 decline due to widespread Pacific deep-water expansion.
Nature Geoscience, 13 (9), .
(doi:10.1038/s41561-020-0610-5).
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.
Text
Yu et al Nature Geocience - Main text_Incl ALL
- Accepted Manuscript
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Accepted/In Press date: 11 June 2020
e-pub ahead of print date: 20 July 2020
Identifiers
Local EPrints ID: 443373
URI: http://eprints.soton.ac.uk/id/eprint/443373
ISSN: 1752-0894
PURE UUID: 18c76ab8-2e30-4fe1-a23e-96d6e61153ef
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Date deposited: 24 Aug 2020 16:30
Last modified: 23 Jul 2022 04:57
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Contributors
Author:
J. Yu
Author:
L. Menviel
Author:
Z. D. Jin
Author:
R. F. Anderson
Author:
Z. Jian
Author:
A. M. Piotrowski
Author:
X. Ma
Author:
F. Zhang
Author:
G. Marino
Author:
J. F. Mcmanus
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