Abrupt Ice Age Shifts in Southern Westerlies and Antarctic Climate Forced from the North
The Southern Hemisphere (SH) mid-latitude westerly winds play a central role in the global climate system via Southern Ocean upwelling, carbon exchange with the deep ocean, Agulhas Leakage, and Antarctic ice sheet stability. Meridional shifts in the SH westerlies have been hypothesized in response t...
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Online Access: | https://boris.unibe.ch/142480/1/Buizert_2018_Nature.pdf https://boris.unibe.ch/142480/2/Buizert_2018_Nature_accepted.pdf https://boris.unibe.ch/142480/ |
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ftunivbern:oai:boris.unibe.ch:142480 2023-08-20T04:02:00+02:00 Abrupt Ice Age Shifts in Southern Westerlies and Antarctic Climate Forced from the North Buizert, Christo Sigl, Michael Severi, Mirko Markle, Bradley R. Wettstein, Justin J. McConnell, Joseph R. Pedro, Joel B. Sodemann, Harald Goto-Azuma, Kumiko Kawamura, Kenji Fujita, Shuji Motoyama, Hideaki Hirabayashi, Motohiro Uemura, Ryu Stenni, Barbara Parrenin, Frédéric He, Feng Fudge, T. J. Steig, Eric J. 2018-11-28 application/pdf https://boris.unibe.ch/142480/1/Buizert_2018_Nature.pdf https://boris.unibe.ch/142480/2/Buizert_2018_Nature_accepted.pdf https://boris.unibe.ch/142480/ eng eng Springer Nature https://boris.unibe.ch/142480/ info:eu-repo/semantics/restrictedAccess info:eu-repo/semantics/openAccess Buizert, Christo; Sigl, Michael; Severi, Mirko; Markle, Bradley R.; Wettstein, Justin J.; McConnell, Joseph R.; Pedro, Joel B.; Sodemann, Harald; Goto-Azuma, Kumiko; Kawamura, Kenji; Fujita, Shuji; Motoyama, Hideaki; Hirabayashi, Motohiro; Uemura, Ryu; Stenni, Barbara; Parrenin, Frédéric; He, Feng; Fudge, T. J.; Steig, Eric J. (2018). Abrupt Ice Age Shifts in Southern Westerlies and Antarctic Climate Forced from the North. Nature, 563(7733), pp. 681-685. Springer Nature 10.1038/s41586-018-0727-5 <http://dx.doi.org/10.1038/s41586-018-0727-5> 530 Physics 540 Chemistry 550 Earth sciences & geology info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion PeerReviewed 2018 ftunivbern https://doi.org/10.1038/s41586-018-0727-5 2023-07-31T21:59:13Z The Southern Hemisphere (SH) mid-latitude westerly winds play a central role in the global climate system via Southern Ocean upwelling, carbon exchange with the deep ocean, Agulhas Leakage, and Antarctic ice sheet stability. Meridional shifts in the SH westerlies have been hypothesized in response to abrupt North Atlantic Dansgaard-Oeschger (DO) climatic events of the last ice age, in parallel with the well-documented shifts of the intertropical convergence zone. Shifting moisture pathways to West Antarctica are consistent with this view, but may represent a Pacific teleconnection pattern. The full SH atmospheric-circulation response to the DO cycle, as well as its impact on Antarctic temperature, have so far remained unclear. Here we use five volcanically-synchronized ice cores to show that the Antarctic temperature response to the DO cycle can be understood as the superposition of two modes: a spatially homogeneous oceanic “bipolar seesaw” mode that lags Northern Hemisphere (NH) climate by about 200 years, and a spatially heterogeneous atmospheric mode that is synchronous with NH abrupt events. Temperature anomalies of the atmospheric mode are similar to those associated with present-day Southern Annular Mode (SAM) variability, rather than the Pacific South America (PSA) pattern. Moreover, deuterium excess records suggest a zonally coherent migration of the SH westerlies over all ocean basins in phase with NH climate. Our work provides a simple conceptual framework for understanding the circum-Antarctic temperature response to abrupt NH climate change. We provide observational evidence for abrupt shifts in the SH westerlies, with ramifications for global ocean circulation and atmospheric CO₂. These coupled changes highlight the necessity of a global, rather than a purely North Atlantic, perspective on the DO cycle. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet North Atlantic Southern Ocean West Antarctica BORIS (Bern Open Repository and Information System, University of Bern) Antarctic Pacific Southern Ocean The Antarctic West Antarctica Nature 563 7733 681 685 |
institution |
Open Polar |
collection |
BORIS (Bern Open Repository and Information System, University of Bern) |
op_collection_id |
ftunivbern |
language |
English |
topic |
530 Physics 540 Chemistry 550 Earth sciences & geology |
spellingShingle |
530 Physics 540 Chemistry 550 Earth sciences & geology Buizert, Christo Sigl, Michael Severi, Mirko Markle, Bradley R. Wettstein, Justin J. McConnell, Joseph R. Pedro, Joel B. Sodemann, Harald Goto-Azuma, Kumiko Kawamura, Kenji Fujita, Shuji Motoyama, Hideaki Hirabayashi, Motohiro Uemura, Ryu Stenni, Barbara Parrenin, Frédéric He, Feng Fudge, T. J. Steig, Eric J. Abrupt Ice Age Shifts in Southern Westerlies and Antarctic Climate Forced from the North |
topic_facet |
530 Physics 540 Chemistry 550 Earth sciences & geology |
description |
The Southern Hemisphere (SH) mid-latitude westerly winds play a central role in the global climate system via Southern Ocean upwelling, carbon exchange with the deep ocean, Agulhas Leakage, and Antarctic ice sheet stability. Meridional shifts in the SH westerlies have been hypothesized in response to abrupt North Atlantic Dansgaard-Oeschger (DO) climatic events of the last ice age, in parallel with the well-documented shifts of the intertropical convergence zone. Shifting moisture pathways to West Antarctica are consistent with this view, but may represent a Pacific teleconnection pattern. The full SH atmospheric-circulation response to the DO cycle, as well as its impact on Antarctic temperature, have so far remained unclear. Here we use five volcanically-synchronized ice cores to show that the Antarctic temperature response to the DO cycle can be understood as the superposition of two modes: a spatially homogeneous oceanic “bipolar seesaw” mode that lags Northern Hemisphere (NH) climate by about 200 years, and a spatially heterogeneous atmospheric mode that is synchronous with NH abrupt events. Temperature anomalies of the atmospheric mode are similar to those associated with present-day Southern Annular Mode (SAM) variability, rather than the Pacific South America (PSA) pattern. Moreover, deuterium excess records suggest a zonally coherent migration of the SH westerlies over all ocean basins in phase with NH climate. Our work provides a simple conceptual framework for understanding the circum-Antarctic temperature response to abrupt NH climate change. We provide observational evidence for abrupt shifts in the SH westerlies, with ramifications for global ocean circulation and atmospheric CO₂. These coupled changes highlight the necessity of a global, rather than a purely North Atlantic, perspective on the DO cycle. |
format |
Article in Journal/Newspaper |
author |
Buizert, Christo Sigl, Michael Severi, Mirko Markle, Bradley R. Wettstein, Justin J. McConnell, Joseph R. Pedro, Joel B. Sodemann, Harald Goto-Azuma, Kumiko Kawamura, Kenji Fujita, Shuji Motoyama, Hideaki Hirabayashi, Motohiro Uemura, Ryu Stenni, Barbara Parrenin, Frédéric He, Feng Fudge, T. J. Steig, Eric J. |
author_facet |
Buizert, Christo Sigl, Michael Severi, Mirko Markle, Bradley R. Wettstein, Justin J. McConnell, Joseph R. Pedro, Joel B. Sodemann, Harald Goto-Azuma, Kumiko Kawamura, Kenji Fujita, Shuji Motoyama, Hideaki Hirabayashi, Motohiro Uemura, Ryu Stenni, Barbara Parrenin, Frédéric He, Feng Fudge, T. J. Steig, Eric J. |
author_sort |
Buizert, Christo |
title |
Abrupt Ice Age Shifts in Southern Westerlies and Antarctic Climate Forced from the North |
title_short |
Abrupt Ice Age Shifts in Southern Westerlies and Antarctic Climate Forced from the North |
title_full |
Abrupt Ice Age Shifts in Southern Westerlies and Antarctic Climate Forced from the North |
title_fullStr |
Abrupt Ice Age Shifts in Southern Westerlies and Antarctic Climate Forced from the North |
title_full_unstemmed |
Abrupt Ice Age Shifts in Southern Westerlies and Antarctic Climate Forced from the North |
title_sort |
abrupt ice age shifts in southern westerlies and antarctic climate forced from the north |
publisher |
Springer Nature |
publishDate |
2018 |
url |
https://boris.unibe.ch/142480/1/Buizert_2018_Nature.pdf https://boris.unibe.ch/142480/2/Buizert_2018_Nature_accepted.pdf https://boris.unibe.ch/142480/ |
geographic |
Antarctic Pacific Southern Ocean The Antarctic West Antarctica |
geographic_facet |
Antarctic Pacific Southern Ocean The Antarctic West Antarctica |
genre |
Antarc* Antarctic Antarctica Ice Sheet North Atlantic Southern Ocean West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet North Atlantic Southern Ocean West Antarctica |
op_source |
Buizert, Christo; Sigl, Michael; Severi, Mirko; Markle, Bradley R.; Wettstein, Justin J.; McConnell, Joseph R.; Pedro, Joel B.; Sodemann, Harald; Goto-Azuma, Kumiko; Kawamura, Kenji; Fujita, Shuji; Motoyama, Hideaki; Hirabayashi, Motohiro; Uemura, Ryu; Stenni, Barbara; Parrenin, Frédéric; He, Feng; Fudge, T. J.; Steig, Eric J. (2018). Abrupt Ice Age Shifts in Southern Westerlies and Antarctic Climate Forced from the North. Nature, 563(7733), pp. 681-685. Springer Nature 10.1038/s41586-018-0727-5 <http://dx.doi.org/10.1038/s41586-018-0727-5> |
op_relation |
https://boris.unibe.ch/142480/ |
op_rights |
info:eu-repo/semantics/restrictedAccess info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1038/s41586-018-0727-5 |
container_title |
Nature |
container_volume |
563 |
container_issue |
7733 |
container_start_page |
681 |
op_container_end_page |
685 |
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1774712377830277120 |