Sources of low-frequency variability in observed Antarctic sea ice
Antarctic sea ice has exhibited significant variability over the satellite record, including a period of prolonged and gradual expansion, as well as a period of sudden decline. A number of mechanisms have been proposed to explain this variability, but how each mechanism manifests spatially and tempo...
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ftethz:oai:www.research-collection.ethz.ch:20.500.11850/673624 2024-06-23T07:45:29+00:00 Sources of low-frequency variability in observed Antarctic sea ice Bonan, David B. Dörr, Jakob Wills, Robert C.J. Thompson, Andrew F. Årthun, Marius 2024 application/application/pdf https://hdl.handle.net/20.500.11850/673624 https://doi.org/10.3929/ethz-b-000673624 en eng Copernicus info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-18-2141-2024 info:eu-repo/semantics/altIdentifier/wos/001216164300001 info:eu-repo/grantAgreement/SNF/Eccellenza/PCEFP2_203376/1 http://hdl.handle.net/20.500.11850/673624 doi:10.3929/ethz-b-000673624 info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International The Cryosphere, 18 (4) info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2024 ftethz https://doi.org/20.500.11850/67362410.3929/ethz-b-00067362410.5194/tc-18-2141-2024 2024-05-29T08:01:17Z Antarctic sea ice has exhibited significant variability over the satellite record, including a period of prolonged and gradual expansion, as well as a period of sudden decline. A number of mechanisms have been proposed to explain this variability, but how each mechanism manifests spatially and temporally remains poorly understood. Here, we use a statistical method called low-frequency component analysis to analyze the spatiotemporal structure of observed Antarctic sea ice concentration variability. The identified patterns reveal distinct modes of low-frequency sea ice variability. The leading mode, which accounts for the large-scale, gradual expansion of sea ice, is associated with the Interdecadal Pacific Oscillation and resembles the observed sea surface temperature trend pattern that climate models have trouble reproducing. The second mode is associated with the central Pacific El Ni & ntilde;o-Southern Oscillation (ENSO) and the Southern Annular Mode and accounts for most of the sea ice variability in the Ross Sea. The third mode is associated with the eastern Pacific ENSO and Amundsen Sea Low and accounts for most of the pan-Antarctic sea ice variability and almost all of the sea ice variability in the Weddell Sea. The third mode is also related to periods of abrupt Antarctic sea ice decline that are associated with a weakening of the circumpolar westerlies, which favors surface warming through a shoaling of the ocean mixed layer and decreased northward Ekman heat transport. Broadly, these results suggest that climate model biases in long-term Antarctic sea ice and large-scale sea surface temperature trends are related to each other and that eastern Pacific ENSO variability is a key ingredient for abrupt Antarctic sea ice changes. ISSN:1994-0416 ISSN:1994-0424 Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Ross Sea Sea ice The Cryosphere Weddell Sea ETH Zürich Research Collection Amundsen Sea Antarctic Pacific Ross Sea Weddell Weddell Sea |
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Open Polar |
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ETH Zürich Research Collection |
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ftethz |
language |
English |
description |
Antarctic sea ice has exhibited significant variability over the satellite record, including a period of prolonged and gradual expansion, as well as a period of sudden decline. A number of mechanisms have been proposed to explain this variability, but how each mechanism manifests spatially and temporally remains poorly understood. Here, we use a statistical method called low-frequency component analysis to analyze the spatiotemporal structure of observed Antarctic sea ice concentration variability. The identified patterns reveal distinct modes of low-frequency sea ice variability. The leading mode, which accounts for the large-scale, gradual expansion of sea ice, is associated with the Interdecadal Pacific Oscillation and resembles the observed sea surface temperature trend pattern that climate models have trouble reproducing. The second mode is associated with the central Pacific El Ni & ntilde;o-Southern Oscillation (ENSO) and the Southern Annular Mode and accounts for most of the sea ice variability in the Ross Sea. The third mode is associated with the eastern Pacific ENSO and Amundsen Sea Low and accounts for most of the pan-Antarctic sea ice variability and almost all of the sea ice variability in the Weddell Sea. The third mode is also related to periods of abrupt Antarctic sea ice decline that are associated with a weakening of the circumpolar westerlies, which favors surface warming through a shoaling of the ocean mixed layer and decreased northward Ekman heat transport. Broadly, these results suggest that climate model biases in long-term Antarctic sea ice and large-scale sea surface temperature trends are related to each other and that eastern Pacific ENSO variability is a key ingredient for abrupt Antarctic sea ice changes. ISSN:1994-0416 ISSN:1994-0424 |
format |
Article in Journal/Newspaper |
author |
Bonan, David B. Dörr, Jakob Wills, Robert C.J. Thompson, Andrew F. Årthun, Marius |
spellingShingle |
Bonan, David B. Dörr, Jakob Wills, Robert C.J. Thompson, Andrew F. Årthun, Marius Sources of low-frequency variability in observed Antarctic sea ice |
author_facet |
Bonan, David B. Dörr, Jakob Wills, Robert C.J. Thompson, Andrew F. Årthun, Marius |
author_sort |
Bonan, David B. |
title |
Sources of low-frequency variability in observed Antarctic sea ice |
title_short |
Sources of low-frequency variability in observed Antarctic sea ice |
title_full |
Sources of low-frequency variability in observed Antarctic sea ice |
title_fullStr |
Sources of low-frequency variability in observed Antarctic sea ice |
title_full_unstemmed |
Sources of low-frequency variability in observed Antarctic sea ice |
title_sort |
sources of low-frequency variability in observed antarctic sea ice |
publisher |
Copernicus |
publishDate |
2024 |
url |
https://hdl.handle.net/20.500.11850/673624 https://doi.org/10.3929/ethz-b-000673624 |
geographic |
Amundsen Sea Antarctic Pacific Ross Sea Weddell Weddell Sea |
geographic_facet |
Amundsen Sea Antarctic Pacific Ross Sea Weddell Weddell Sea |
genre |
Amundsen Sea Antarc* Antarctic Ross Sea Sea ice The Cryosphere Weddell Sea |
genre_facet |
Amundsen Sea Antarc* Antarctic Ross Sea Sea ice The Cryosphere Weddell Sea |
op_source |
The Cryosphere, 18 (4) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-18-2141-2024 info:eu-repo/semantics/altIdentifier/wos/001216164300001 info:eu-repo/grantAgreement/SNF/Eccellenza/PCEFP2_203376/1 http://hdl.handle.net/20.500.11850/673624 doi:10.3929/ethz-b-000673624 |
op_rights |
info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International |
op_doi |
https://doi.org/20.500.11850/67362410.3929/ethz-b-00067362410.5194/tc-18-2141-2024 |
_version_ |
1802639900999155712 |