Atmospheric influences on the anomalous 2016 Antarctic sea ice decay
In contrast to the Arctic, where total sea ice extent (SIE) has been decreasing for the last three decades, Antarctic SIE has shown a small, but significant, increase during the same time period. However, in 2016, an unusually early onset of the melt season was observed; the maximum Antarctic SIE wa...
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ftethz:oai:www.research-collection.ethz.ch:20.500.11850/256143 2023-05-15T13:45:54+02:00 Atmospheric influences on the anomalous 2016 Antarctic sea ice decay Schlosser, Elisabeth Haumann, Alexander Raphael, Marilyn N. 2018 application/application/pdf https://hdl.handle.net/20.500.11850/256143 https://doi.org/10.3929/ethz-b-000256143 en eng Copernicus info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-12-1103-2018 info:eu-repo/semantics/altIdentifier/wos/000428551200001 http://hdl.handle.net/20.500.11850/256143 doi:10.3929/ethz-b-000256143 info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International CC-BY The Cryosphere, 12 (3) info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2018 ftethz https://doi.org/20.500.11850/256143 https://doi.org/10.3929/ethz-b-000256143 https://doi.org/10.5194/tc-12-1103-2018 2022-04-25T13:26:15Z In contrast to the Arctic, where total sea ice extent (SIE) has been decreasing for the last three decades, Antarctic SIE has shown a small, but significant, increase during the same time period. However, in 2016, an unusually early onset of the melt season was observed; the maximum Antarctic SIE was already reached as early as August rather than the end of September, and was followed by a rapid decrease. The decay was particularly strong in November, when Antarctic SIE exhibited a negative anomaly (compared to the 1979–2015 average) of approximately 2 million km2. ECMWF Interim reanalysis data showed that the early onset of the melt and the rapid decrease in sea ice area (SIA) and SIE were associated with atmospheric flow patterns related to a positive zonal wave number three (ZW3) index, i.e., synoptic situations leading to strong meridional flow and anomalously strong southward heat advection in the regions of strongest sea ice decline. A persistently positive ZW3 index from May to August suggests that SIE decrease was preconditioned by SIA decrease. In particular, in the first third of November northerly flow conditions in the Weddell Sea and the Western Pacific triggered accelerated sea ice decay, which was continued in the following weeks due to positive feedback effects, leading to the unusually low November SIE. In 2016, the monthly mean Southern Annular Mode (SAM) index reached its second lowest November value since the beginning of the satellite observations. A better spatial and temporal coverage of reliable ice thickness data is needed to assess the change in ice mass rather than ice area. ISSN:1994-0416 ISSN:1994-0424 Article in Journal/Newspaper Antarc* Antarctic Arctic Sea ice The Cryosphere Weddell Sea ETH Zürich Research Collection Antarctic Arctic Pacific Weddell Weddell Sea |
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Open Polar |
collection |
ETH Zürich Research Collection |
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ftethz |
language |
English |
description |
In contrast to the Arctic, where total sea ice extent (SIE) has been decreasing for the last three decades, Antarctic SIE has shown a small, but significant, increase during the same time period. However, in 2016, an unusually early onset of the melt season was observed; the maximum Antarctic SIE was already reached as early as August rather than the end of September, and was followed by a rapid decrease. The decay was particularly strong in November, when Antarctic SIE exhibited a negative anomaly (compared to the 1979–2015 average) of approximately 2 million km2. ECMWF Interim reanalysis data showed that the early onset of the melt and the rapid decrease in sea ice area (SIA) and SIE were associated with atmospheric flow patterns related to a positive zonal wave number three (ZW3) index, i.e., synoptic situations leading to strong meridional flow and anomalously strong southward heat advection in the regions of strongest sea ice decline. A persistently positive ZW3 index from May to August suggests that SIE decrease was preconditioned by SIA decrease. In particular, in the first third of November northerly flow conditions in the Weddell Sea and the Western Pacific triggered accelerated sea ice decay, which was continued in the following weeks due to positive feedback effects, leading to the unusually low November SIE. In 2016, the monthly mean Southern Annular Mode (SAM) index reached its second lowest November value since the beginning of the satellite observations. A better spatial and temporal coverage of reliable ice thickness data is needed to assess the change in ice mass rather than ice area. ISSN:1994-0416 ISSN:1994-0424 |
format |
Article in Journal/Newspaper |
author |
Schlosser, Elisabeth Haumann, Alexander Raphael, Marilyn N. |
spellingShingle |
Schlosser, Elisabeth Haumann, Alexander Raphael, Marilyn N. Atmospheric influences on the anomalous 2016 Antarctic sea ice decay |
author_facet |
Schlosser, Elisabeth Haumann, Alexander Raphael, Marilyn N. |
author_sort |
Schlosser, Elisabeth |
title |
Atmospheric influences on the anomalous 2016 Antarctic sea ice decay |
title_short |
Atmospheric influences on the anomalous 2016 Antarctic sea ice decay |
title_full |
Atmospheric influences on the anomalous 2016 Antarctic sea ice decay |
title_fullStr |
Atmospheric influences on the anomalous 2016 Antarctic sea ice decay |
title_full_unstemmed |
Atmospheric influences on the anomalous 2016 Antarctic sea ice decay |
title_sort |
atmospheric influences on the anomalous 2016 antarctic sea ice decay |
publisher |
Copernicus |
publishDate |
2018 |
url |
https://hdl.handle.net/20.500.11850/256143 https://doi.org/10.3929/ethz-b-000256143 |
geographic |
Antarctic Arctic Pacific Weddell Weddell Sea |
geographic_facet |
Antarctic Arctic Pacific Weddell Weddell Sea |
genre |
Antarc* Antarctic Arctic Sea ice The Cryosphere Weddell Sea |
genre_facet |
Antarc* Antarctic Arctic Sea ice The Cryosphere Weddell Sea |
op_source |
The Cryosphere, 12 (3) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-12-1103-2018 info:eu-repo/semantics/altIdentifier/wos/000428551200001 http://hdl.handle.net/20.500.11850/256143 doi:10.3929/ethz-b-000256143 |
op_rights |
info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/20.500.11850/256143 https://doi.org/10.3929/ethz-b-000256143 https://doi.org/10.5194/tc-12-1103-2018 |
_version_ |
1766232102034997248 |