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 ????13...
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American Geophysical Union
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ftanucanberra:oai:openresearch-repository.anu.edu.au:1885/247315 2024-01-14T10:02:26+01:00 Poorly ventilated deep ocean at the Last Glacial Maximum inferred from carbon isotopes: A data-model comparison study Menviel, L Yu, Jimin Joos, F. Mouchet, A.T. Meissner, KA England, Matthew Heathcote application/pdf http://hdl.handle.net/1885/247315 https://doi.org/10.1002/2016PA003024 https://openresearch-repository.anu.edu.au/bitstream/1885/247315/4/01_Menviel_Poorly_ventilated_deep_ocean_2017.pdf.jpg en_AU eng American Geophysical Union http://purl.org/au-research/grants/arc/DE150100107 http://purl.org/au-research/grants/arc/FL100100214 http://purl.org/au-research/grants/arc/FT140100993 http://purl.org/au-research/grants/arc/DP140101393 0883-8305 http://hdl.handle.net/1885/247315 doi:10.1002/2016PA003024 https://openresearch-repository.anu.edu.au/bitstream/1885/247315/4/01_Menviel_Poorly_ventilated_deep_ocean_2017.pdf.jpg ©2016. American Geophysical Union Paleoceanography Journal article ftanucanberra https://doi.org/10.1002/2016PA003024 2023-12-15T09:36:09Z 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 ????13C distribution, thereby improving our understanding of glacial/interglacial atmospheric CO2 variations. We find that the mean ocean ????13C change can be explained by a 378 ± 88 Gt C (2????) smaller LGM terrestrial carbon reservoir compared to the Holocene. Critically, in this model, differences in the oceanic ????13C 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. This project was supported by the Australian Research Council. L. Menviel, and M. England acknowledge funding from the Australian Research Council grants DE150100107 and FL100100214, respectively. J. Yu acknowledges funding from the Australian Research Council grants FT140100993, DP140101393, K. Meissner acknowledges support from a UNSW Faculty of Science Silverstar award. F.J. acknowledges funding by the Swiss National Science Foundation. Article in Journal/Newspaper Antarc* Antarctic North Atlantic Deep Water North Atlantic Australian National University: ANU Digital Collections Antarctic Pacific Paleoceanography 32 1 2 17 |
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Australian National University: ANU Digital Collections |
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ftanucanberra |
language |
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 ????13C distribution, thereby improving our understanding of glacial/interglacial atmospheric CO2 variations. We find that the mean ocean ????13C change can be explained by a 378 ± 88 Gt C (2????) smaller LGM terrestrial carbon reservoir compared to the Holocene. Critically, in this model, differences in the oceanic ????13C 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. This project was supported by the Australian Research Council. L. Menviel, and M. England acknowledge funding from the Australian Research Council grants DE150100107 and FL100100214, respectively. J. Yu acknowledges funding from the Australian Research Council grants FT140100993, DP140101393, K. Meissner acknowledges support from a UNSW Faculty of Science Silverstar award. F.J. acknowledges funding by the Swiss National Science Foundation. |
format |
Article in Journal/Newspaper |
author |
Menviel, L Yu, Jimin Joos, F. Mouchet, A.T. Meissner, KA England, Matthew Heathcote |
spellingShingle |
Menviel, L Yu, Jimin Joos, F. Mouchet, A.T. Meissner, KA England, Matthew Heathcote Poorly ventilated deep ocean at the Last Glacial Maximum inferred from carbon isotopes: A data-model comparison study |
author_facet |
Menviel, L Yu, Jimin Joos, F. Mouchet, A.T. Meissner, KA England, Matthew Heathcote |
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 |
publisher |
American Geophysical Union |
url |
http://hdl.handle.net/1885/247315 https://doi.org/10.1002/2016PA003024 https://openresearch-repository.anu.edu.au/bitstream/1885/247315/4/01_Menviel_Poorly_ventilated_deep_ocean_2017.pdf.jpg |
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 |
http://purl.org/au-research/grants/arc/DE150100107 http://purl.org/au-research/grants/arc/FL100100214 http://purl.org/au-research/grants/arc/FT140100993 http://purl.org/au-research/grants/arc/DP140101393 0883-8305 http://hdl.handle.net/1885/247315 doi:10.1002/2016PA003024 https://openresearch-repository.anu.edu.au/bitstream/1885/247315/4/01_Menviel_Poorly_ventilated_deep_ocean_2017.pdf.jpg |
op_rights |
©2016. American Geophysical Union |
op_doi |
https://doi.org/10.1002/2016PA003024 |
container_title |
Paleoceanography |
container_volume |
32 |
container_issue |
1 |
container_start_page |
2 |
op_container_end_page |
17 |
_version_ |
1788057466371571712 |