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...
Published in: | The Cryosphere |
---|---|
Main Author: | |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
Copernicus
2022
|
Subjects: | |
Online Access: | https://doi.org/10.5194/tc-16-4087-2022 |
id |
ftzenodo:oai:zenodo.org:11071387 |
---|---|
record_format |
openpolar |
spelling |
ftzenodo:oai:zenodo.org:11071387 2024-09-15T17:48:25+00:00 An indicator of sea ice variability for the Antarctic marginal ice zone Vichi, Marcello 2022-10-10 https://doi.org/10.5194/tc-16-4087-2022 unknown Copernicus https://zenodo.org/communities/scale_south_africa https://doi.org/10.5194/tc-16-4087-2022 oai:zenodo.org:11071387 info:eu-repo/semantics/openAccess Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode The Cryosphere, 16, 4087-4106, (2022-10-10) info:eu-repo/semantics/article 2022 ftzenodo https://doi.org/10.5194/tc-16-4087-2022 2024-07-26T13:26:19Z 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 Sea ice Southern Ocean The Cryosphere Zenodo The Cryosphere 16 10 4087 4106 |
institution |
Open Polar |
collection |
Zenodo |
op_collection_id |
ftzenodo |
language |
unknown |
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 |
Vichi, Marcello |
spellingShingle |
Vichi, Marcello An indicator of sea ice variability for the Antarctic marginal ice zone |
author_facet |
Vichi, Marcello |
author_sort |
Vichi, Marcello |
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 |
publishDate |
2022 |
url |
https://doi.org/10.5194/tc-16-4087-2022 |
genre |
Antarc* Antarctic Sea ice Southern Ocean The Cryosphere |
genre_facet |
Antarc* Antarctic Sea ice Southern Ocean The Cryosphere |
op_source |
The Cryosphere, 16, 4087-4106, (2022-10-10) |
op_relation |
https://zenodo.org/communities/scale_south_africa https://doi.org/10.5194/tc-16-4087-2022 oai:zenodo.org:11071387 |
op_rights |
info:eu-repo/semantics/openAccess Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode |
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 |
_version_ |
1810289606991544320 |