Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling
Declining atmospheric CO2 concentrations are considered the primary driver for the Cenozoic Greenhouse-Icehouse transition, ~34 million years ago. A role for tectonically opening Southern Ocean gateways, initiating the onset of a thermally isolating Antarctic Circumpolar Current, has been disputed a...
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Nature Research
2021
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ftnerc:oai:nora.nerc.ac.uk:531383 2023-05-15T13:41:46+02:00 Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling Sauermilch, I. Whittaker, J.M. Klocker, A. Munday, D.R. Hochmuth, K. Bijl, P.K. LaCasce, J.H. 2021-12 text http://nora.nerc.ac.uk/id/eprint/531383/ https://nora.nerc.ac.uk/id/eprint/531383/1/s41467-021-26658-1.pdf https://www.nature.com/articles/s41467-021-26658-1 en eng Nature Research https://nora.nerc.ac.uk/id/eprint/531383/1/s41467-021-26658-1.pdf Sauermilch, I.; Whittaker, J.M.; Klocker, A.; Munday, D.R. orcid:0000-0003-1920-708X Hochmuth, K.; Bijl, P.K.; LaCasce, J.H. 2021 Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling. Nature Communications, 12, 6465. 8, pp. https://doi.org/10.1038/s41467-021-26658-1 <https://doi.org/10.1038/s41467-021-26658-1> cc_by_4 CC-BY Publication - Article PeerReviewed 2021 ftnerc https://doi.org/10.1038/s41467-021-26658-1 2023-02-04T19:52:43Z Declining atmospheric CO2 concentrations are considered the primary driver for the Cenozoic Greenhouse-Icehouse transition, ~34 million years ago. A role for tectonically opening Southern Ocean gateways, initiating the onset of a thermally isolating Antarctic Circumpolar Current, has been disputed as ocean models have not reproduced expected heat transport to the Antarctic coast. Here we use high-resolution ocean simulations with detailed paleobathymetry to demonstrate that tectonics did play a fundamental role in reorganising Southern Ocean circulation patterns and heat transport, consistent with available proxy data. When at least one gateway (Tasmanian or Drake) is shallow (300 m), gyres transport warm waters towards Antarctica. When the second gateway subsides below 300 m, these gyres weaken and cause a dramatic cooling (average of 2–4 °C, up to 5 °C) of Antarctic surface waters whilst the ACC remains weak. Our results demonstrate that tectonic changes are crucial for Southern Ocean climate change and should be carefully considered in constraining long-term climate sensitivity to CO2. Article in Journal/Newspaper Antarc* Antarctic Antarctica Southern Ocean Natural Environment Research Council: NERC Open Research Archive Antarctic Southern Ocean The Antarctic Nature Communications 12 1 |
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Natural Environment Research Council: NERC Open Research Archive |
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ftnerc |
language |
English |
description |
Declining atmospheric CO2 concentrations are considered the primary driver for the Cenozoic Greenhouse-Icehouse transition, ~34 million years ago. A role for tectonically opening Southern Ocean gateways, initiating the onset of a thermally isolating Antarctic Circumpolar Current, has been disputed as ocean models have not reproduced expected heat transport to the Antarctic coast. Here we use high-resolution ocean simulations with detailed paleobathymetry to demonstrate that tectonics did play a fundamental role in reorganising Southern Ocean circulation patterns and heat transport, consistent with available proxy data. When at least one gateway (Tasmanian or Drake) is shallow (300 m), gyres transport warm waters towards Antarctica. When the second gateway subsides below 300 m, these gyres weaken and cause a dramatic cooling (average of 2–4 °C, up to 5 °C) of Antarctic surface waters whilst the ACC remains weak. Our results demonstrate that tectonic changes are crucial for Southern Ocean climate change and should be carefully considered in constraining long-term climate sensitivity to CO2. |
format |
Article in Journal/Newspaper |
author |
Sauermilch, I. Whittaker, J.M. Klocker, A. Munday, D.R. Hochmuth, K. Bijl, P.K. LaCasce, J.H. |
spellingShingle |
Sauermilch, I. Whittaker, J.M. Klocker, A. Munday, D.R. Hochmuth, K. Bijl, P.K. LaCasce, J.H. Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling |
author_facet |
Sauermilch, I. Whittaker, J.M. Klocker, A. Munday, D.R. Hochmuth, K. Bijl, P.K. LaCasce, J.H. |
author_sort |
Sauermilch, I. |
title |
Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling |
title_short |
Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling |
title_full |
Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling |
title_fullStr |
Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling |
title_full_unstemmed |
Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling |
title_sort |
gateway-driven weakening of ocean gyres leads to southern ocean cooling |
publisher |
Nature Research |
publishDate |
2021 |
url |
http://nora.nerc.ac.uk/id/eprint/531383/ https://nora.nerc.ac.uk/id/eprint/531383/1/s41467-021-26658-1.pdf https://www.nature.com/articles/s41467-021-26658-1 |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Antarctica Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica Southern Ocean |
op_relation |
https://nora.nerc.ac.uk/id/eprint/531383/1/s41467-021-26658-1.pdf Sauermilch, I.; Whittaker, J.M.; Klocker, A.; Munday, D.R. orcid:0000-0003-1920-708X Hochmuth, K.; Bijl, P.K.; LaCasce, J.H. 2021 Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling. Nature Communications, 12, 6465. 8, pp. https://doi.org/10.1038/s41467-021-26658-1 <https://doi.org/10.1038/s41467-021-26658-1> |
op_rights |
cc_by_4 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1038/s41467-021-26658-1 |
container_title |
Nature Communications |
container_volume |
12 |
container_issue |
1 |
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1766157648698277888 |