Poorly ventilated deep ocean at the Last Glacial Maximum inferred from carbon isotopes: A data-model comparison study
Atmospheric CO2 was ∼90 ppmv lower at the Last Glacial Maximum (LGM) compared to the late Holocene, but the mechanisms responsible for this change remain elusive. Here we employ a carbon isotope-enabled Earth System Model to investigate the role of ocean circulation in setting the LGM oceanic δ13C d...
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ftpubman:oai:pure.mpg.de:item_2382324 2023-08-20T04:02:28+02:00 Poorly ventilated deep ocean at the Last Glacial Maximum inferred from carbon isotopes: A data-model comparison study Menviel, L. Yu, J. Joos, F. Mouchet, A. Meissner, K. England, M. 2017-01 http://hdl.handle.net/11858/00-001M-0000-002C-3BF0-D eng eng info:eu-repo/semantics/altIdentifier/doi/10.1002/2016PA003024 http://hdl.handle.net/11858/00-001M-0000-002C-3BF0-D Paleoceanography info:eu-repo/semantics/article 2017 ftpubman https://doi.org/10.1002/2016PA003024 2023-08-01T22:19:03Z Atmospheric CO2 was ∼90 ppmv lower at the Last Glacial Maximum (LGM) compared to the late Holocene, but the mechanisms responsible for this change remain elusive. Here we employ a carbon isotope-enabled Earth System Model to investigate the role of ocean circulation in setting the LGM oceanic δ13C distribution, thereby improving our understanding of glacial/interglacial atmospheric CO2 variations. We find that the mean ocean δ13C change can be explained by a 378 ± 88 Gt C(2σ) smaller LGM terrestrial carbon reservoir compared to the Holocene. Critically, in this model, differences in the oceanic δ13C spatial pattern can only be reconciled with a LGM ocean circulation state characterized by a weak (10-15 Sv) and relatively shallow (2000-2500 m) North Atlantic Deep Water cell, reduced Antarctic Bottom Water transport (≤10 Sv globally integrated), and relatively weak (6-8 Sv) and shallow (1000-1500 m) North Pacific Intermediate Water formation. This oceanic circulation state is corroborated by results from the isotope-enabled Bern3D ocean model and further confirmed by high LGM ventilation ages in the deep ocean, particularly in the deep South Atlantic and South Pacific. This suggests a poorly ventilated glacial deep ocean which would have facilitated the sequestration of carbon lost from the terrestrial biosphere and atmosphere. © 2016. American Geophysical Union. All Rights Reserved. Article in Journal/Newspaper Antarc* Antarctic North Atlantic Deep Water North Atlantic Max Planck Society: MPG.PuRe Antarctic Pacific Paleoceanography 32 1 2 17 |
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Max Planck Society: MPG.PuRe |
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ftpubman |
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English |
description |
Atmospheric CO2 was ∼90 ppmv lower at the Last Glacial Maximum (LGM) compared to the late Holocene, but the mechanisms responsible for this change remain elusive. Here we employ a carbon isotope-enabled Earth System Model to investigate the role of ocean circulation in setting the LGM oceanic δ13C distribution, thereby improving our understanding of glacial/interglacial atmospheric CO2 variations. We find that the mean ocean δ13C change can be explained by a 378 ± 88 Gt C(2σ) smaller LGM terrestrial carbon reservoir compared to the Holocene. Critically, in this model, differences in the oceanic δ13C spatial pattern can only be reconciled with a LGM ocean circulation state characterized by a weak (10-15 Sv) and relatively shallow (2000-2500 m) North Atlantic Deep Water cell, reduced Antarctic Bottom Water transport (≤10 Sv globally integrated), and relatively weak (6-8 Sv) and shallow (1000-1500 m) North Pacific Intermediate Water formation. This oceanic circulation state is corroborated by results from the isotope-enabled Bern3D ocean model and further confirmed by high LGM ventilation ages in the deep ocean, particularly in the deep South Atlantic and South Pacific. This suggests a poorly ventilated glacial deep ocean which would have facilitated the sequestration of carbon lost from the terrestrial biosphere and atmosphere. © 2016. American Geophysical Union. All Rights Reserved. |
format |
Article in Journal/Newspaper |
author |
Menviel, L. Yu, J. Joos, F. Mouchet, A. Meissner, K. England, M. |
spellingShingle |
Menviel, L. Yu, J. Joos, F. Mouchet, A. Meissner, K. England, M. Poorly ventilated deep ocean at the Last Glacial Maximum inferred from carbon isotopes: A data-model comparison study |
author_facet |
Menviel, L. Yu, J. Joos, F. Mouchet, A. Meissner, K. England, M. |
author_sort |
Menviel, L. |
title |
Poorly ventilated deep ocean at the Last Glacial Maximum inferred from carbon isotopes: A data-model comparison study |
title_short |
Poorly ventilated deep ocean at the Last Glacial Maximum inferred from carbon isotopes: A data-model comparison study |
title_full |
Poorly ventilated deep ocean at the Last Glacial Maximum inferred from carbon isotopes: A data-model comparison study |
title_fullStr |
Poorly ventilated deep ocean at the Last Glacial Maximum inferred from carbon isotopes: A data-model comparison study |
title_full_unstemmed |
Poorly ventilated deep ocean at the Last Glacial Maximum inferred from carbon isotopes: A data-model comparison study |
title_sort |
poorly ventilated deep ocean at the last glacial maximum inferred from carbon isotopes: a data-model comparison study |
publishDate |
2017 |
url |
http://hdl.handle.net/11858/00-001M-0000-002C-3BF0-D |
geographic |
Antarctic Pacific |
geographic_facet |
Antarctic Pacific |
genre |
Antarc* Antarctic North Atlantic Deep Water North Atlantic |
genre_facet |
Antarc* Antarctic North Atlantic Deep Water North Atlantic |
op_source |
Paleoceanography |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1002/2016PA003024 http://hdl.handle.net/11858/00-001M-0000-002C-3BF0-D |
op_doi |
https://doi.org/10.1002/2016PA003024 |
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Paleoceanography |
container_volume |
32 |
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1 |
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2 |
op_container_end_page |
17 |
_version_ |
1774712919725965312 |