Antarctic sea-ice thickness retrieval from ICESat: inter-comparison of different approaches
Accurate circum-Antarctic sea-ice thickness is urgently required to better understand the different sea-ice cover evolution in both polar regions. Satellite radar and laser altimetry are currently the most promising tools for sea-ice thickness retrieval. We present qualitative inter-comparisons of w...
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ftunivtasecite:oai:ecite.utas.edu.au:114858 2023-05-15T13:49:03+02:00 Antarctic sea-ice thickness retrieval from ICESat: inter-comparison of different approaches Kern, S Ozsoy-Cicek, B Worby, AP 2016 application/pdf https://doi.org/10.3390/rs8070538 http://ecite.utas.edu.au/114858 en eng M D P I AG http://ecite.utas.edu.au/114858/1/Kern et al 2016.pdf http://dx.doi.org/10.3390/rs8070538 Kern, S and Ozsoy-Cicek, B and Worby, AP, Antarctic sea-ice thickness retrieval from ICESat: inter-comparison of different approaches, Remote Sensing, 8, (7) Article 538. ISSN 2072-4292 (2016) [Refereed Article] http://ecite.utas.edu.au/114858 Earth Sciences Oceanography Physical Oceanography Refereed Article PeerReviewed 2016 ftunivtasecite https://doi.org/10.3390/rs8070538 2019-12-13T22:14:43Z Accurate circum-Antarctic sea-ice thickness is urgently required to better understand the different sea-ice cover evolution in both polar regions. Satellite radar and laser altimetry are currently the most promising tools for sea-ice thickness retrieval. We present qualitative inter-comparisons of winter and spring circum-Antarctic sea-ice thickness computed with different approaches from Ice Cloud and land Elevation Satellite (ICESat) laser altimeter total (sea ice plus snow) freeboard estimates. We find that approach A, which assumes total freeboard equals snow depth, and approach B, which uses empirical linear relationships between freeboard and thickness, provide the lowest sea-ice thickness and the smallest winter-to-spring increase in seasonal average modal and mean sea-ice thickness: A: 0.0 m and 0.04 m, B: 0.17 and 0.16 m, respectively. Approach C uses contemporary snow depth from satellite microwave radiometry, and we derive comparably large sea-ice thickness. Here we observe an unrealistically large winter-to-spring increase in seasonal average modal and mean sea-ice thickness of 0.68 m and 0.65 m, respectively, which we attribute to biases in the snow depth. We present a conceptually new approach D. It assumes that the two-layer system (sea ice, snow) can be represented by one layer. This layer has a modified density, which takes into account the influence of the snow on sea-ice buoyancy. With approach D we obtain thickness values and a winter-to-spring increase in average modal and mean sea-ice thickness of 0.17 m and 0.23 m, respectively, which lay between those of approaches B and C. We discuss retrieval uncertainty, systematic uncertainty sources, and the impact of grid resolution. We find that sea-ice thickness obtained with approaches C and D agrees best with independent sea-ice thickness information - if we take into account the potential bias of in situ and ship-based observations. Article in Journal/Newspaper Antarc* Antarctic Sea ice eCite UTAS (University of Tasmania) Antarctic Remote Sensing 8 7 538 |
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Open Polar |
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eCite UTAS (University of Tasmania) |
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ftunivtasecite |
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English |
topic |
Earth Sciences Oceanography Physical Oceanography |
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Earth Sciences Oceanography Physical Oceanography Kern, S Ozsoy-Cicek, B Worby, AP Antarctic sea-ice thickness retrieval from ICESat: inter-comparison of different approaches |
topic_facet |
Earth Sciences Oceanography Physical Oceanography |
description |
Accurate circum-Antarctic sea-ice thickness is urgently required to better understand the different sea-ice cover evolution in both polar regions. Satellite radar and laser altimetry are currently the most promising tools for sea-ice thickness retrieval. We present qualitative inter-comparisons of winter and spring circum-Antarctic sea-ice thickness computed with different approaches from Ice Cloud and land Elevation Satellite (ICESat) laser altimeter total (sea ice plus snow) freeboard estimates. We find that approach A, which assumes total freeboard equals snow depth, and approach B, which uses empirical linear relationships between freeboard and thickness, provide the lowest sea-ice thickness and the smallest winter-to-spring increase in seasonal average modal and mean sea-ice thickness: A: 0.0 m and 0.04 m, B: 0.17 and 0.16 m, respectively. Approach C uses contemporary snow depth from satellite microwave radiometry, and we derive comparably large sea-ice thickness. Here we observe an unrealistically large winter-to-spring increase in seasonal average modal and mean sea-ice thickness of 0.68 m and 0.65 m, respectively, which we attribute to biases in the snow depth. We present a conceptually new approach D. It assumes that the two-layer system (sea ice, snow) can be represented by one layer. This layer has a modified density, which takes into account the influence of the snow on sea-ice buoyancy. With approach D we obtain thickness values and a winter-to-spring increase in average modal and mean sea-ice thickness of 0.17 m and 0.23 m, respectively, which lay between those of approaches B and C. We discuss retrieval uncertainty, systematic uncertainty sources, and the impact of grid resolution. We find that sea-ice thickness obtained with approaches C and D agrees best with independent sea-ice thickness information - if we take into account the potential bias of in situ and ship-based observations. |
format |
Article in Journal/Newspaper |
author |
Kern, S Ozsoy-Cicek, B Worby, AP |
author_facet |
Kern, S Ozsoy-Cicek, B Worby, AP |
author_sort |
Kern, S |
title |
Antarctic sea-ice thickness retrieval from ICESat: inter-comparison of different approaches |
title_short |
Antarctic sea-ice thickness retrieval from ICESat: inter-comparison of different approaches |
title_full |
Antarctic sea-ice thickness retrieval from ICESat: inter-comparison of different approaches |
title_fullStr |
Antarctic sea-ice thickness retrieval from ICESat: inter-comparison of different approaches |
title_full_unstemmed |
Antarctic sea-ice thickness retrieval from ICESat: inter-comparison of different approaches |
title_sort |
antarctic sea-ice thickness retrieval from icesat: inter-comparison of different approaches |
publisher |
M D P I AG |
publishDate |
2016 |
url |
https://doi.org/10.3390/rs8070538 http://ecite.utas.edu.au/114858 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Sea ice |
genre_facet |
Antarc* Antarctic Sea ice |
op_relation |
http://ecite.utas.edu.au/114858/1/Kern et al 2016.pdf http://dx.doi.org/10.3390/rs8070538 Kern, S and Ozsoy-Cicek, B and Worby, AP, Antarctic sea-ice thickness retrieval from ICESat: inter-comparison of different approaches, Remote Sensing, 8, (7) Article 538. ISSN 2072-4292 (2016) [Refereed Article] http://ecite.utas.edu.au/114858 |
op_doi |
https://doi.org/10.3390/rs8070538 |
container_title |
Remote Sensing |
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8 |
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7 |
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538 |
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1766250690358804480 |