Can we reconstruct the formation of large open-ocean polynyas in the Southern Ocean using ice core records?
Large open-ocean polynyas, defined as ice-free areas within the sea ice pack, have only rarely been observed in the Southern Ocean over the past decades. In addition to smaller recent events, an impressive sequence occurred in the Weddell Sea in 1974, 1975 and 1976 with openings of more than 300 000...
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ftdoajarticles:oai:doaj.org/article:a78d50268b3a4520a293a9b2ed364716 2023-05-15T13:30:59+02:00 Can we reconstruct the formation of large open-ocean polynyas in the Southern Ocean using ice core records? H. Goosse Q. Dalaiden M. G. P. Cavitte L. Zhang 2021-01-01T00:00:00Z https://doi.org/10.5194/cp-17-111-2021 https://doaj.org/article/a78d50268b3a4520a293a9b2ed364716 EN eng Copernicus Publications https://cp.copernicus.org/articles/17/111/2021/cp-17-111-2021.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-17-111-2021 1814-9324 1814-9332 https://doaj.org/article/a78d50268b3a4520a293a9b2ed364716 Climate of the Past, Vol 17, Pp 111-131 (2021) Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 article 2021 ftdoajarticles https://doi.org/10.5194/cp-17-111-2021 2022-12-31T04:50:01Z Large open-ocean polynyas, defined as ice-free areas within the sea ice pack, have only rarely been observed in the Southern Ocean over the past decades. In addition to smaller recent events, an impressive sequence occurred in the Weddell Sea in 1974, 1975 and 1976 with openings of more than 300 000 km 2 that lasted the full winter. These big events have a huge impact on the sea ice cover, deep-water formation, and, more generally, on the Southern Ocean and the Antarctic climate. However, we have no estimate of the frequency of the occurrence of such large open-ocean polynyas before the 1970s. Our goal here is to test if polynya activity could be reconstructed using continental records and, specifically, observations derived from ice cores. The fingerprint of big open-ocean polynyas is first described in reconstructions based on data from weather stations, in ice cores for the 1970s and in climate models. It shows a signal characterized by a surface air warming and increased precipitation in coastal regions adjacent to the eastern part of the Weddell Sea, where several high-resolution ice cores have been collected. The signal of the isotopic composition of precipitation is more ambiguous; thus, we base our reconstructions on surface mass balance records alone. A first reconstruction is obtained by performing a simple average of standardized records. Given the similarity between the observed signal and the one simulated in models, we also use data assimilation to reconstruct past polynya activity. The impact of open-ocean polynyas on the continent is not large enough, compared with the changes due to factors such as atmospheric variability, to detect the polynya signal without ambiguity, and additional observations would be required to clearly discriminate the years with and without open-ocean polynya. Thus, it is reasonable to consider that, in these preliminary reconstructions, some high snow accumulation events may be wrongly interpreted as the consequence of polynya formation and some years with polynya ... Article in Journal/Newspaper Antarc* Antarctic ice core ice pack Sea ice Southern Ocean Weddell Sea Directory of Open Access Journals: DOAJ Articles Antarctic Southern Ocean The Antarctic Weddell Weddell Sea Climate of the Past 17 1 111 131 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
spellingShingle |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 H. Goosse Q. Dalaiden M. G. P. Cavitte L. Zhang Can we reconstruct the formation of large open-ocean polynyas in the Southern Ocean using ice core records? |
topic_facet |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
description |
Large open-ocean polynyas, defined as ice-free areas within the sea ice pack, have only rarely been observed in the Southern Ocean over the past decades. In addition to smaller recent events, an impressive sequence occurred in the Weddell Sea in 1974, 1975 and 1976 with openings of more than 300 000 km 2 that lasted the full winter. These big events have a huge impact on the sea ice cover, deep-water formation, and, more generally, on the Southern Ocean and the Antarctic climate. However, we have no estimate of the frequency of the occurrence of such large open-ocean polynyas before the 1970s. Our goal here is to test if polynya activity could be reconstructed using continental records and, specifically, observations derived from ice cores. The fingerprint of big open-ocean polynyas is first described in reconstructions based on data from weather stations, in ice cores for the 1970s and in climate models. It shows a signal characterized by a surface air warming and increased precipitation in coastal regions adjacent to the eastern part of the Weddell Sea, where several high-resolution ice cores have been collected. The signal of the isotopic composition of precipitation is more ambiguous; thus, we base our reconstructions on surface mass balance records alone. A first reconstruction is obtained by performing a simple average of standardized records. Given the similarity between the observed signal and the one simulated in models, we also use data assimilation to reconstruct past polynya activity. The impact of open-ocean polynyas on the continent is not large enough, compared with the changes due to factors such as atmospheric variability, to detect the polynya signal without ambiguity, and additional observations would be required to clearly discriminate the years with and without open-ocean polynya. Thus, it is reasonable to consider that, in these preliminary reconstructions, some high snow accumulation events may be wrongly interpreted as the consequence of polynya formation and some years with polynya ... |
format |
Article in Journal/Newspaper |
author |
H. Goosse Q. Dalaiden M. G. P. Cavitte L. Zhang |
author_facet |
H. Goosse Q. Dalaiden M. G. P. Cavitte L. Zhang |
author_sort |
H. Goosse |
title |
Can we reconstruct the formation of large open-ocean polynyas in the Southern Ocean using ice core records? |
title_short |
Can we reconstruct the formation of large open-ocean polynyas in the Southern Ocean using ice core records? |
title_full |
Can we reconstruct the formation of large open-ocean polynyas in the Southern Ocean using ice core records? |
title_fullStr |
Can we reconstruct the formation of large open-ocean polynyas in the Southern Ocean using ice core records? |
title_full_unstemmed |
Can we reconstruct the formation of large open-ocean polynyas in the Southern Ocean using ice core records? |
title_sort |
can we reconstruct the formation of large open-ocean polynyas in the southern ocean using ice core records? |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/cp-17-111-2021 https://doaj.org/article/a78d50268b3a4520a293a9b2ed364716 |
geographic |
Antarctic Southern Ocean The Antarctic Weddell Weddell Sea |
geographic_facet |
Antarctic Southern Ocean The Antarctic Weddell Weddell Sea |
genre |
Antarc* Antarctic ice core ice pack Sea ice Southern Ocean Weddell Sea |
genre_facet |
Antarc* Antarctic ice core ice pack Sea ice Southern Ocean Weddell Sea |
op_source |
Climate of the Past, Vol 17, Pp 111-131 (2021) |
op_relation |
https://cp.copernicus.org/articles/17/111/2021/cp-17-111-2021.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-17-111-2021 1814-9324 1814-9332 https://doaj.org/article/a78d50268b3a4520a293a9b2ed364716 |
op_doi |
https://doi.org/10.5194/cp-17-111-2021 |
container_title |
Climate of the Past |
container_volume |
17 |
container_issue |
1 |
container_start_page |
111 |
op_container_end_page |
131 |
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1766014811877933056 |