Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling
Abstract Declining atmospheric CO 2 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...
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ftoslouniv:oai:www.duo.uio.no:10852/94324 2023-05-15T13:38:27+02:00 Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling Sauermilch, Isabel Whittaker, Joanne M. Klocker, Andreas Munday, David R. Hochmuth, Katharina Bijl, Peter K. Lacasce, Joseph Henry 2021-11-24T23:33:57Z http://hdl.handle.net/10852/94324 http://urn.nb.no/URN:NBN:no-96874 https://doi.org/10.1038/s41467-021-26658-1 EN eng Nature Portfolio http://urn.nb.no/URN:NBN:no-96874 Sauermilch, Isabel Whittaker, Joanne M. Klocker, Andreas Munday, David R. Hochmuth, Katharina Bijl, Peter K. Lacasce, Joseph Henry . Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling. Nature Communications. 2021, 12, 1-8 http://hdl.handle.net/10852/94324 1958698 info:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Nature Communications&rft.volume=12&rft.spage=1&rft.date=2021 Nature Communications 12 1 https://doi.org/10.1038/s41467-021-26658-1 URN:NBN:no-96874 Fulltext https://www.duo.uio.no/bitstream/handle/10852/94324/1/Sauermilchetal41467-021-26658-1.pdf Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ CC-BY 2041-1723 Journal article Tidsskriftartikkel Peer reviewed PublishedVersion 2021 ftoslouniv https://doi.org/10.1038/s41467-021-26658-1 2022-06-15T22:34:03Z Abstract Declining atmospheric CO 2 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 CO 2 . Article in Journal/Newspaper Antarc* Antarctic Antarctica Southern Ocean Universitet i Oslo: Digitale utgivelser ved UiO (DUO) Antarctic Southern Ocean The Antarctic Nature Communications 12 1 |
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Universitet i Oslo: Digitale utgivelser ved UiO (DUO) |
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ftoslouniv |
language |
English |
description |
Abstract Declining atmospheric CO 2 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 CO 2 . |
format |
Article in Journal/Newspaper |
author |
Sauermilch, Isabel Whittaker, Joanne M. Klocker, Andreas Munday, David R. Hochmuth, Katharina Bijl, Peter K. Lacasce, Joseph Henry |
spellingShingle |
Sauermilch, Isabel Whittaker, Joanne M. Klocker, Andreas Munday, David R. Hochmuth, Katharina Bijl, Peter K. Lacasce, Joseph Henry Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling |
author_facet |
Sauermilch, Isabel Whittaker, Joanne M. Klocker, Andreas Munday, David R. Hochmuth, Katharina Bijl, Peter K. Lacasce, Joseph Henry |
author_sort |
Sauermilch, Isabel |
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 Portfolio |
publishDate |
2021 |
url |
http://hdl.handle.net/10852/94324 http://urn.nb.no/URN:NBN:no-96874 https://doi.org/10.1038/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_source |
2041-1723 |
op_relation |
http://urn.nb.no/URN:NBN:no-96874 Sauermilch, Isabel Whittaker, Joanne M. Klocker, Andreas Munday, David R. Hochmuth, Katharina Bijl, Peter K. Lacasce, Joseph Henry . Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling. Nature Communications. 2021, 12, 1-8 http://hdl.handle.net/10852/94324 1958698 info:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Nature Communications&rft.volume=12&rft.spage=1&rft.date=2021 Nature Communications 12 1 https://doi.org/10.1038/s41467-021-26658-1 URN:NBN:no-96874 Fulltext https://www.duo.uio.no/bitstream/handle/10852/94324/1/Sauermilchetal41467-021-26658-1.pdf |
op_rights |
Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ |
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 |
_version_ |
1766106423953981440 |