Century-scale perspectives on observed and simulated Southern Ocean sea ice trends from proxy reconstructions
Since 1979 when continuous satellite observations began, Southern Ocean sea ice cover has increased, whilst global coupled climate models simulate a decrease over the same period. It is uncertain whether the observed trends are anthropogenically forced or due to internal variability, or whether the...
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Online Access: | https://doi.org/10.1002/2016JC012111 http://ecite.utas.edu.au/112179 |
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ftunivtasecite:oai:ecite.utas.edu.au:112179 2023-05-15T13:49:03+02:00 Century-scale perspectives on observed and simulated Southern Ocean sea ice trends from proxy reconstructions Hobbs, W Curran, M Abram, N Thomas, ER 2016 application/pdf https://doi.org/10.1002/2016JC012111 http://ecite.utas.edu.au/112179 en eng Wiley-Blackwell Publishing, Inc. http://ecite.utas.edu.au/112179/1/112179 final.pdf http://dx.doi.org/10.1002/2016JC012111 Hobbs, W and Curran, M and Abram, N and Thomas, ER, Century-scale perspectives on observed and simulated Southern Ocean sea ice trends from proxy reconstructions, Journal of Geophysical Research: Oceans, 121, (10) pp. 7804-7818. ISSN 2169-9275 (2016) [Refereed Article] http://ecite.utas.edu.au/112179 Earth Sciences Oceanography Physical Oceanography Refereed Article PeerReviewed 2016 ftunivtasecite https://doi.org/10.1002/2016JC012111 2019-12-13T22:12:28Z Since 1979 when continuous satellite observations began, Southern Ocean sea ice cover has increased, whilst global coupled climate models simulate a decrease over the same period. It is uncertain whether the observed trends are anthropogenically forced or due to internal variability, or whether the apparent discrepancy between models and observations can be explained by internal variability. The shortness of the satellite record is one source of this uncertainty, and a possible solution is to use proxy reconstructions, which extend the analysis period but at the expense of higher observational uncertainty. In this work, we evaluate the utility for change detection of 20th century Southern Ocean sea ice proxies. We find that there are reliable proxies for the East Antarctic, Amundsen, Bellingshausen and Weddell sectors in late winter, and for the Weddell Sea in late autumn. Models and reconstructions agree that sea ice extent in the East Antarctic, Amundsen and Bellingshausen Seas has decreased since the early 1970s, consistent with an anthropogenic response. However, the decrease is small compared to internal variability, and the change is not robustly detectable. We also find that optimal fingerprinting filters out much of the uncertainty in proxy reconstructions. The Ross Sea is a confounding factor, with a significant increase in sea ice since 1979 that is not captured by climate models; however, existing proxy reconstructions of this region are not yet sufficiently reliable for formal change detection. Article in Journal/Newspaper Antarc* Antarctic Ross Sea Sea ice Southern Ocean Weddell Sea eCite UTAS (University of Tasmania) Antarctic Ross Sea Southern Ocean Weddell Weddell Sea Journal of Geophysical Research: Oceans 121 10 7804 7818 |
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English |
topic |
Earth Sciences Oceanography Physical Oceanography |
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Earth Sciences Oceanography Physical Oceanography Hobbs, W Curran, M Abram, N Thomas, ER Century-scale perspectives on observed and simulated Southern Ocean sea ice trends from proxy reconstructions |
topic_facet |
Earth Sciences Oceanography Physical Oceanography |
description |
Since 1979 when continuous satellite observations began, Southern Ocean sea ice cover has increased, whilst global coupled climate models simulate a decrease over the same period. It is uncertain whether the observed trends are anthropogenically forced or due to internal variability, or whether the apparent discrepancy between models and observations can be explained by internal variability. The shortness of the satellite record is one source of this uncertainty, and a possible solution is to use proxy reconstructions, which extend the analysis period but at the expense of higher observational uncertainty. In this work, we evaluate the utility for change detection of 20th century Southern Ocean sea ice proxies. We find that there are reliable proxies for the East Antarctic, Amundsen, Bellingshausen and Weddell sectors in late winter, and for the Weddell Sea in late autumn. Models and reconstructions agree that sea ice extent in the East Antarctic, Amundsen and Bellingshausen Seas has decreased since the early 1970s, consistent with an anthropogenic response. However, the decrease is small compared to internal variability, and the change is not robustly detectable. We also find that optimal fingerprinting filters out much of the uncertainty in proxy reconstructions. The Ross Sea is a confounding factor, with a significant increase in sea ice since 1979 that is not captured by climate models; however, existing proxy reconstructions of this region are not yet sufficiently reliable for formal change detection. |
format |
Article in Journal/Newspaper |
author |
Hobbs, W Curran, M Abram, N Thomas, ER |
author_facet |
Hobbs, W Curran, M Abram, N Thomas, ER |
author_sort |
Hobbs, W |
title |
Century-scale perspectives on observed and simulated Southern Ocean sea ice trends from proxy reconstructions |
title_short |
Century-scale perspectives on observed and simulated Southern Ocean sea ice trends from proxy reconstructions |
title_full |
Century-scale perspectives on observed and simulated Southern Ocean sea ice trends from proxy reconstructions |
title_fullStr |
Century-scale perspectives on observed and simulated Southern Ocean sea ice trends from proxy reconstructions |
title_full_unstemmed |
Century-scale perspectives on observed and simulated Southern Ocean sea ice trends from proxy reconstructions |
title_sort |
century-scale perspectives on observed and simulated southern ocean sea ice trends from proxy reconstructions |
publisher |
Wiley-Blackwell Publishing, Inc. |
publishDate |
2016 |
url |
https://doi.org/10.1002/2016JC012111 http://ecite.utas.edu.au/112179 |
geographic |
Antarctic Ross Sea Southern Ocean Weddell Weddell Sea |
geographic_facet |
Antarctic Ross Sea Southern Ocean Weddell Weddell Sea |
genre |
Antarc* Antarctic Ross Sea Sea ice Southern Ocean Weddell Sea |
genre_facet |
Antarc* Antarctic Ross Sea Sea ice Southern Ocean Weddell Sea |
op_relation |
http://ecite.utas.edu.au/112179/1/112179 final.pdf http://dx.doi.org/10.1002/2016JC012111 Hobbs, W and Curran, M and Abram, N and Thomas, ER, Century-scale perspectives on observed and simulated Southern Ocean sea ice trends from proxy reconstructions, Journal of Geophysical Research: Oceans, 121, (10) pp. 7804-7818. ISSN 2169-9275 (2016) [Refereed Article] http://ecite.utas.edu.au/112179 |
op_doi |
https://doi.org/10.1002/2016JC012111 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
121 |
container_issue |
10 |
container_start_page |
7804 |
op_container_end_page |
7818 |
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1766250678679764992 |