Interhemispheric asymmetry in transient global warming: The role of Drake Passage
Climate models predict that the Northern Hemisphere (NH) will warm faster than the Southern Hemisphere (SH) in response to increasing greenhouse gases, and observations show that this trend has already begun to occur. This interhemispheric asymmetry has largely been attributed to land-ocean differen...
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ftunswworks:oai:unsworks.library.unsw.edu.au:1959.4/53692 2023-05-15T13:52:09+02:00 Interhemispheric asymmetry in transient global warming: The role of Drake Passage Hutchinson, David England, Matthew Santoso, Agus Hogg, A 2013 application/pdf http://hdl.handle.net/1959.4/53692 https://unsworks.unsw.edu.au/bitstreams/e7c93823-d390-4ecc-b8b5-1305c9f479b8/download https://doi.org/10.1002/grl.50341 EN eng http://purl.org/au-research/grants/nhmrc/CE110001028 http://purl.org/au-research/grants/arc/CE110001028 http://hdl.handle.net/1959.4/53692 https://unsworks.unsw.edu.au/bitstreams/e7c93823-d390-4ecc-b8b5-1305c9f479b8/download http://dx.doi.org/10.1002/grl.50341 open access https://purl.org/coar/access_right/c_abf2 CC BY-NC-ND 3.0 https://creativecommons.org/licenses/by-nc-nd/3.0/au/ free_to_read Copyright (2013) American Geophysical Union. Published version available at: http://dx.doi.org/10.1002/grl.50341 CC-BY-NC-ND urn:ISSN:0094-8276 Geophysical Research Letters, 40, 8, 1587-1593 journal article http://purl.org/coar/resource_type/c_6501 2013 ftunswworks https://doi.org/10.1002/grl.50341 2022-08-09T07:40:53Z Climate models predict that the Northern Hemisphere (NH) will warm faster than the Southern Hemisphere (SH) in response to increasing greenhouse gases, and observations show that this trend has already begun to occur. This interhemispheric asymmetry has largely been attributed to land-ocean differences between the hemispheres and Arctic sea ice melt, while the role of ocean currents in setting this asymmetry is less well understood. This study isolates the impact of an open Southern Ocean gateway upon the interhemispheric asymmetry in transient global warming by forcing a fully coupled climate model with an increasing CO2 scenario with and without a land bridge across Drake Passage (DP). It is found that over the transient warming period, the NH-SH surface warming asymmetry is reduced in the DP closed case, by approximately 41% for sea surface temperature and approximately 6% for surface air temperature. In the DP open case, sea ice extent is far greater in the SH than in the DP closed case, whereas the sea ice response to warming in the NH is insensitive to whether or not DP is closed. These results illustrate that part of the interhemispheric asymmetry in surface warming is due to the Antarctic Circumpolar Current (ACC) thermally isolating Antarctica. The ACC limits ocean heat transport across the DP latitudes and allows a much greater coverage of sea ice in the Southern Ocean than would be the case in the absence of a circumpolar ocean. Article in Journal/Newspaper Antarc* Antarctic Antarctica Arctic Drake Passage Global warming Sea ice Southern Ocean UNSW Sydney (The University of New South Wales): UNSWorks Antarctic Arctic Drake Passage Southern Ocean The Antarctic Geophysical Research Letters 40 8 1587 1593 |
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Open Polar |
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UNSW Sydney (The University of New South Wales): UNSWorks |
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ftunswworks |
language |
English |
description |
Climate models predict that the Northern Hemisphere (NH) will warm faster than the Southern Hemisphere (SH) in response to increasing greenhouse gases, and observations show that this trend has already begun to occur. This interhemispheric asymmetry has largely been attributed to land-ocean differences between the hemispheres and Arctic sea ice melt, while the role of ocean currents in setting this asymmetry is less well understood. This study isolates the impact of an open Southern Ocean gateway upon the interhemispheric asymmetry in transient global warming by forcing a fully coupled climate model with an increasing CO2 scenario with and without a land bridge across Drake Passage (DP). It is found that over the transient warming period, the NH-SH surface warming asymmetry is reduced in the DP closed case, by approximately 41% for sea surface temperature and approximately 6% for surface air temperature. In the DP open case, sea ice extent is far greater in the SH than in the DP closed case, whereas the sea ice response to warming in the NH is insensitive to whether or not DP is closed. These results illustrate that part of the interhemispheric asymmetry in surface warming is due to the Antarctic Circumpolar Current (ACC) thermally isolating Antarctica. The ACC limits ocean heat transport across the DP latitudes and allows a much greater coverage of sea ice in the Southern Ocean than would be the case in the absence of a circumpolar ocean. |
format |
Article in Journal/Newspaper |
author |
Hutchinson, David England, Matthew Santoso, Agus Hogg, A |
spellingShingle |
Hutchinson, David England, Matthew Santoso, Agus Hogg, A Interhemispheric asymmetry in transient global warming: The role of Drake Passage |
author_facet |
Hutchinson, David England, Matthew Santoso, Agus Hogg, A |
author_sort |
Hutchinson, David |
title |
Interhemispheric asymmetry in transient global warming: The role of Drake Passage |
title_short |
Interhemispheric asymmetry in transient global warming: The role of Drake Passage |
title_full |
Interhemispheric asymmetry in transient global warming: The role of Drake Passage |
title_fullStr |
Interhemispheric asymmetry in transient global warming: The role of Drake Passage |
title_full_unstemmed |
Interhemispheric asymmetry in transient global warming: The role of Drake Passage |
title_sort |
interhemispheric asymmetry in transient global warming: the role of drake passage |
publishDate |
2013 |
url |
http://hdl.handle.net/1959.4/53692 https://unsworks.unsw.edu.au/bitstreams/e7c93823-d390-4ecc-b8b5-1305c9f479b8/download https://doi.org/10.1002/grl.50341 |
geographic |
Antarctic Arctic Drake Passage Southern Ocean The Antarctic |
geographic_facet |
Antarctic Arctic Drake Passage Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Antarctica Arctic Drake Passage Global warming Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica Arctic Drake Passage Global warming Sea ice Southern Ocean |
op_source |
urn:ISSN:0094-8276 Geophysical Research Letters, 40, 8, 1587-1593 |
op_relation |
http://purl.org/au-research/grants/nhmrc/CE110001028 http://purl.org/au-research/grants/arc/CE110001028 http://hdl.handle.net/1959.4/53692 https://unsworks.unsw.edu.au/bitstreams/e7c93823-d390-4ecc-b8b5-1305c9f479b8/download http://dx.doi.org/10.1002/grl.50341 |
op_rights |
open access https://purl.org/coar/access_right/c_abf2 CC BY-NC-ND 3.0 https://creativecommons.org/licenses/by-nc-nd/3.0/au/ free_to_read Copyright (2013) American Geophysical Union. Published version available at: http://dx.doi.org/10.1002/grl.50341 |
op_rightsnorm |
CC-BY-NC-ND |
op_doi |
https://doi.org/10.1002/grl.50341 |
container_title |
Geophysical Research Letters |
container_volume |
40 |
container_issue |
8 |
container_start_page |
1587 |
op_container_end_page |
1593 |
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1766256416372293632 |