An indicator of sea ice variability for the Antarctic marginal ice zone
Remote-sensing records over the last 40 years have revealed large year-to-year global and regional variability in Antarctic sea ice extent. Sea ice area and extent are useful climatic indicators of large-scale variability, but they do not allow the quantification of regions of distinct variability i...
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ftdoajarticles:oai:doaj.org/article:e748934e77314ce6a3abf35164ff8dae 2023-05-15T13:59:05+02:00 An indicator of sea ice variability for the Antarctic marginal ice zone M. Vichi 2022-10-01T00:00:00Z https://doi.org/10.5194/tc-16-4087-2022 https://doaj.org/article/e748934e77314ce6a3abf35164ff8dae EN eng Copernicus Publications https://tc.copernicus.org/articles/16/4087/2022/tc-16-4087-2022.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-16-4087-2022 1994-0416 1994-0424 https://doaj.org/article/e748934e77314ce6a3abf35164ff8dae The Cryosphere, Vol 16, Pp 4087-4106 (2022) Environmental sciences GE1-350 Geology QE1-996.5 article 2022 ftdoajarticles https://doi.org/10.5194/tc-16-4087-2022 2022-12-30T19:53:05Z Remote-sensing records over the last 40 years have revealed large year-to-year global and regional variability in Antarctic sea ice extent. Sea ice area and extent are useful climatic indicators of large-scale variability, but they do not allow the quantification of regions of distinct variability in sea ice concentration (SIC). This is particularly relevant in the marginal ice zone (MIZ), which is a transitional region between the open ocean and pack ice, where the exchanges between ocean, sea ice and atmosphere are more intense. The MIZ is circumpolar and broader in the Antarctic than in the Arctic. Its extent is inferred from satellite-derived SIC using the 15 %–80 % range, assumed to be indicative of open drift or partly closed sea ice conditions typical of the ice edge. This proxy has been proven effective in the Arctic, but it is deemed less reliable in the Southern Ocean, where sea ice type is unrelated to the concentration value, since wave penetration and free-drift conditions have been reported with 100 % cover. The aim of this paper is to propose an alternative indicator for detecting MIZ conditions in Antarctic sea ice, which can be used to quantify variability at the climatological scale on the ice-covered Southern Ocean over the seasons, as well as to derive maps of probability of encountering a certain degree of variability in the expected monthly SIC value. The proposed indicator is based on statistical properties of the SIC; it has been tested on the available climate data records to derive maps of the MIZ distribution over the year and compared with the threshold-based MIZ definition. The results present a revised view of the circumpolar MIZ variability and seasonal cycle, with a rapid increase in the extent and saturation in winter, as opposed to the steady increase from summer to spring reported in the literature. It also reconciles the discordant MIZ extent estimates using the SIC threshold from different algorithms. This indicator complements the use of the MIZ extent and fraction, allowing ... Article in Journal/Newspaper Antarc* Antarctic Arctic Sea ice Southern Ocean The Cryosphere Directory of Open Access Journals: DOAJ Articles Arctic Antarctic Southern Ocean The Antarctic The Cryosphere 16 10 4087 4106 |
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Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 M. Vichi An indicator of sea ice variability for the Antarctic marginal ice zone |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Remote-sensing records over the last 40 years have revealed large year-to-year global and regional variability in Antarctic sea ice extent. Sea ice area and extent are useful climatic indicators of large-scale variability, but they do not allow the quantification of regions of distinct variability in sea ice concentration (SIC). This is particularly relevant in the marginal ice zone (MIZ), which is a transitional region between the open ocean and pack ice, where the exchanges between ocean, sea ice and atmosphere are more intense. The MIZ is circumpolar and broader in the Antarctic than in the Arctic. Its extent is inferred from satellite-derived SIC using the 15 %–80 % range, assumed to be indicative of open drift or partly closed sea ice conditions typical of the ice edge. This proxy has been proven effective in the Arctic, but it is deemed less reliable in the Southern Ocean, where sea ice type is unrelated to the concentration value, since wave penetration and free-drift conditions have been reported with 100 % cover. The aim of this paper is to propose an alternative indicator for detecting MIZ conditions in Antarctic sea ice, which can be used to quantify variability at the climatological scale on the ice-covered Southern Ocean over the seasons, as well as to derive maps of probability of encountering a certain degree of variability in the expected monthly SIC value. The proposed indicator is based on statistical properties of the SIC; it has been tested on the available climate data records to derive maps of the MIZ distribution over the year and compared with the threshold-based MIZ definition. The results present a revised view of the circumpolar MIZ variability and seasonal cycle, with a rapid increase in the extent and saturation in winter, as opposed to the steady increase from summer to spring reported in the literature. It also reconciles the discordant MIZ extent estimates using the SIC threshold from different algorithms. This indicator complements the use of the MIZ extent and fraction, allowing ... |
format |
Article in Journal/Newspaper |
author |
M. Vichi |
author_facet |
M. Vichi |
author_sort |
M. Vichi |
title |
An indicator of sea ice variability for the Antarctic marginal ice zone |
title_short |
An indicator of sea ice variability for the Antarctic marginal ice zone |
title_full |
An indicator of sea ice variability for the Antarctic marginal ice zone |
title_fullStr |
An indicator of sea ice variability for the Antarctic marginal ice zone |
title_full_unstemmed |
An indicator of sea ice variability for the Antarctic marginal ice zone |
title_sort |
indicator of sea ice variability for the antarctic marginal ice zone |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://doi.org/10.5194/tc-16-4087-2022 https://doaj.org/article/e748934e77314ce6a3abf35164ff8dae |
geographic |
Arctic Antarctic Southern Ocean The Antarctic |
geographic_facet |
Arctic Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Arctic Sea ice Southern Ocean The Cryosphere |
genre_facet |
Antarc* Antarctic Arctic Sea ice Southern Ocean The Cryosphere |
op_source |
The Cryosphere, Vol 16, Pp 4087-4106 (2022) |
op_relation |
https://tc.copernicus.org/articles/16/4087/2022/tc-16-4087-2022.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-16-4087-2022 1994-0416 1994-0424 https://doaj.org/article/e748934e77314ce6a3abf35164ff8dae |
op_doi |
https://doi.org/10.5194/tc-16-4087-2022 |
container_title |
The Cryosphere |
container_volume |
16 |
container_issue |
10 |
container_start_page |
4087 |
op_container_end_page |
4106 |
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1766267470897741824 |