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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Online Access: | https://epic.awi.de/id/eprint/54912/ https://hdl.handle.net/10013/epic.3a0ccf87-5eea-465e-baaa-15579d5401a9 |
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ftawi:oai:epic.awi.de:54912 2024-09-15T17:47:06+00:00 Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling Sauermilch, Isabel Whittaker, Joanne M. Klocker, Andreas Munday, David Hochmuth, Katharina Bijl, Peter K LaCasce, J. 2021-11-09 https://epic.awi.de/id/eprint/54912/ https://hdl.handle.net/10013/epic.3a0ccf87-5eea-465e-baaa-15579d5401a9 unknown Nature Sauermilch, I. , Whittaker, J. M. , Klocker, A. , Munday, D. , Hochmuth, K. orcid:0000-0003-2789-2179 , Bijl, P. K. and LaCasce, J. (2021) Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling , Nature Communications, 12 (6465), pp. 1-8 . doi:10.1038/s41467-021-26658-1 <https://doi.org/10.1038/s41467-021-26658-1> , hdl:10013/epic.3a0ccf87-5eea-465e-baaa-15579d5401a9 EPIC3Nature Communications, Nature, 12(6465), pp. 1-8 Article isiRev 2021 ftawi https://doi.org/10.1038/s41467-021-26658-1 2024-06-24T04:27:29Z 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 paleo- bathymetry 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 Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Nature Communications 12 1 |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
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ftawi |
language |
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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 paleo- bathymetry 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, Isabel Whittaker, Joanne M. Klocker, Andreas Munday, David Hochmuth, Katharina Bijl, Peter K LaCasce, J. |
spellingShingle |
Sauermilch, Isabel Whittaker, Joanne M. Klocker, Andreas Munday, David Hochmuth, Katharina Bijl, Peter K LaCasce, J. Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling |
author_facet |
Sauermilch, Isabel Whittaker, Joanne M. Klocker, Andreas Munday, David Hochmuth, Katharina Bijl, Peter K LaCasce, J. |
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 |
publishDate |
2021 |
url |
https://epic.awi.de/id/eprint/54912/ https://hdl.handle.net/10013/epic.3a0ccf87-5eea-465e-baaa-15579d5401a9 |
genre |
Antarc* Antarctic Antarctica Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica Southern Ocean |
op_source |
EPIC3Nature Communications, Nature, 12(6465), pp. 1-8 |
op_relation |
Sauermilch, I. , Whittaker, J. M. , Klocker, A. , Munday, D. , Hochmuth, K. orcid:0000-0003-2789-2179 , Bijl, P. K. and LaCasce, J. (2021) Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling , Nature Communications, 12 (6465), pp. 1-8 . doi:10.1038/s41467-021-26658-1 <https://doi.org/10.1038/s41467-021-26658-1> , hdl:10013/epic.3a0ccf87-5eea-465e-baaa-15579d5401a9 |
op_doi |
https://doi.org/10.1038/s41467-021-26658-1 |
container_title |
Nature Communications |
container_volume |
12 |
container_issue |
1 |
_version_ |
1810495734460448768 |