Mapping of Active Frazil for Antarctic Coastal Polynyas, With an Estimation of Sea‐Ice Production
Abstract The importance of the area of active frazil and associated high sea‐ice production in Antarctic coastal polynyas has been increasingly recognized in recent in situ and high‐resolution satellite observations. However, the occurrence and spatial distribution of active‐frazil area are not well...
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| Format: | Article |
| Language: | English |
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Wiley
2021-03-01
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| Series: | Geophysical Research Letters |
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| Online Access: | https://doi.org/10.1029/2020GL091353 |
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| author | K. Nakata K. I. Ohshima S. Nihashi |
| author_facet | K. Nakata K. I. Ohshima S. Nihashi |
| author_sort | K. Nakata |
| collection | DOAJ |
| description | Abstract The importance of the area of active frazil and associated high sea‐ice production in Antarctic coastal polynyas has been increasingly recognized in recent in situ and high‐resolution satellite observations. However, the occurrence and spatial distribution of active‐frazil area are not well understood. We present the first mapping of active‐frazil area for Antarctic coastal polynyas, based on the thin ice algorithm of AMSR‐E that discriminates active‐frazil area. Mapping of sea‐ice production is presented by taking account of active‐frazil area. Active‐frazil area is predominant along East Antarctica, particularly very close to the coast, locally leading to very high ice‐production rates exceeding 20 m/yr. For frazil‐dominant polynyas, estimated ice production is ∼20%–50% higher compared with previous studies. Analyses of all the major polynyas suggest that active‐frazil extent depends on offshore wind and air temperature, while ice production is determined by offshore wind only. |
| format | Article |
| id | doaj-art-259e19d263c84e1896b1ce4f064ceb4c |
| institution | OA Journals |
| issn | 0094-8276 1944-8007 |
| language | English |
| publishDate | 2021-03-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geophysical Research Letters |
| spelling | doaj-art-259e19d263c84e1896b1ce4f064ceb4c2025-08-20T01:48:15ZengWileyGeophysical Research Letters0094-82761944-80072021-03-01486n/an/a10.1029/2020GL091353Mapping of Active Frazil for Antarctic Coastal Polynyas, With an Estimation of Sea‐Ice ProductionK. Nakata0K. I. Ohshima1S. Nihashi2Institute of Low Temperature Science, Hokkaido University Sapporo JapanInstitute of Low Temperature Science, Hokkaido University Sapporo JapanDepartment of Engineering for Innovation National Institute of Technology, Tomakomai College Tomakomai JapanAbstract The importance of the area of active frazil and associated high sea‐ice production in Antarctic coastal polynyas has been increasingly recognized in recent in situ and high‐resolution satellite observations. However, the occurrence and spatial distribution of active‐frazil area are not well understood. We present the first mapping of active‐frazil area for Antarctic coastal polynyas, based on the thin ice algorithm of AMSR‐E that discriminates active‐frazil area. Mapping of sea‐ice production is presented by taking account of active‐frazil area. Active‐frazil area is predominant along East Antarctica, particularly very close to the coast, locally leading to very high ice‐production rates exceeding 20 m/yr. For frazil‐dominant polynyas, estimated ice production is ∼20%–50% higher compared with previous studies. Analyses of all the major polynyas suggest that active‐frazil extent depends on offshore wind and air temperature, while ice production is determined by offshore wind only.https://doi.org/10.1029/2020GL091353coastal polynyafrazil iceice typepassive microwavessea ice productionSouthern Ocean |
| spellingShingle | K. Nakata K. I. Ohshima S. Nihashi Mapping of Active Frazil for Antarctic Coastal Polynyas, With an Estimation of Sea‐Ice Production Geophysical Research Letters coastal polynya frazil ice ice type passive microwaves sea ice production Southern Ocean |
| title | Mapping of Active Frazil for Antarctic Coastal Polynyas, With an Estimation of Sea‐Ice Production |
| title_full | Mapping of Active Frazil for Antarctic Coastal Polynyas, With an Estimation of Sea‐Ice Production |
| title_fullStr | Mapping of Active Frazil for Antarctic Coastal Polynyas, With an Estimation of Sea‐Ice Production |
| title_full_unstemmed | Mapping of Active Frazil for Antarctic Coastal Polynyas, With an Estimation of Sea‐Ice Production |
| title_short | Mapping of Active Frazil for Antarctic Coastal Polynyas, With an Estimation of Sea‐Ice Production |
| title_sort | mapping of active frazil for antarctic coastal polynyas with an estimation of sea ice production |
| topic | coastal polynya frazil ice ice type passive microwaves sea ice production Southern Ocean |
| url | https://doi.org/10.1029/2020GL091353 |
| work_keys_str_mv | AT knakata mappingofactivefrazilforantarcticcoastalpolynyaswithanestimationofseaiceproduction AT kiohshima mappingofactivefrazilforantarcticcoastalpolynyaswithanestimationofseaiceproduction AT snihashi mappingofactivefrazilforantarcticcoastalpolynyaswithanestimationofseaiceproduction |