The relation between sea ice thickness and freeboard in the Arctic
Retrieval of Arctic sea ice thickness from CryoSat-2 radar altimeter freeboard data requires observational data to verify the relation between these two variables. In this study in-situ ice and snow data from 689 observation sites, obtained during the Sever expeditions in the 1980s, have been used t...
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ftcopernicus:oai:publications.copernicus.org:tc7286 2023-05-15T15:00:30+02:00 The relation between sea ice thickness and freeboard in the Arctic Alexandrov, V. Sandven, S. Wahlin, J. Johannessen, O. M. 2018-09-27 application/pdf https://doi.org/10.5194/tc-4-373-2010 https://tc.copernicus.org/articles/4/373/2010/ eng eng doi:10.5194/tc-4-373-2010 https://tc.copernicus.org/articles/4/373/2010/ eISSN: 1994-0424 Text 2018 ftcopernicus https://doi.org/10.5194/tc-4-373-2010 2020-07-20T16:26:21Z Retrieval of Arctic sea ice thickness from CryoSat-2 radar altimeter freeboard data requires observational data to verify the relation between these two variables. In this study in-situ ice and snow data from 689 observation sites, obtained during the Sever expeditions in the 1980s, have been used to establish an empirical relation between thickness and freeboard of FY ice in late winter. Estimates of mean and variability of snow depth, snow density and ice density were produced on the basis of many field observations. These estimates have been used in the hydrostatic equilibrium equation to retrieve ice thickness as a function of ice freeboard, snow depth and snow/ice density. The accuracy of the ice thickness retrieval has been calculated from the estimated variability in ice and snow parameters and error of ice freeboard measurements. It is found that uncertainties of ice density and freeboard are the major sources of error in ice thickness calculation. For FY ice, retrieval of ≈ 1.0 m (2.0 m) thickness has an uncertainty of 46% (37%), and for MY ice, retrieval of 2.4 m (3.0 m) thickness has an uncertainty of 20% (18%), assuming that the freeboard error is ± 0.03 m for both ice types. For MY ice the main uncertainty is ice density error, since the freeboard error is relatively smaller than that for FY ice. If the freeboard error can be reduced to 0.01 m by averaging measurements from CryoSat-2, the error in thickness retrieval is reduced to about 32% for a 1.0 m thick FY floe and to about 18% for a 2.4 m thick MY floe. The remaining error is dominated by uncertainty in ice density. Provision of improved ice density data is therefore important for accurate retrieval of ice thickness from CryoSat-2 data. Text Arctic Sea ice Copernicus Publications: E-Journals Arctic Sever ENVELOPE(166.083,166.083,62.917,62.917) The Cryosphere 4 3 373 380 |
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Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Retrieval of Arctic sea ice thickness from CryoSat-2 radar altimeter freeboard data requires observational data to verify the relation between these two variables. In this study in-situ ice and snow data from 689 observation sites, obtained during the Sever expeditions in the 1980s, have been used to establish an empirical relation between thickness and freeboard of FY ice in late winter. Estimates of mean and variability of snow depth, snow density and ice density were produced on the basis of many field observations. These estimates have been used in the hydrostatic equilibrium equation to retrieve ice thickness as a function of ice freeboard, snow depth and snow/ice density. The accuracy of the ice thickness retrieval has been calculated from the estimated variability in ice and snow parameters and error of ice freeboard measurements. It is found that uncertainties of ice density and freeboard are the major sources of error in ice thickness calculation. For FY ice, retrieval of ≈ 1.0 m (2.0 m) thickness has an uncertainty of 46% (37%), and for MY ice, retrieval of 2.4 m (3.0 m) thickness has an uncertainty of 20% (18%), assuming that the freeboard error is ± 0.03 m for both ice types. For MY ice the main uncertainty is ice density error, since the freeboard error is relatively smaller than that for FY ice. If the freeboard error can be reduced to 0.01 m by averaging measurements from CryoSat-2, the error in thickness retrieval is reduced to about 32% for a 1.0 m thick FY floe and to about 18% for a 2.4 m thick MY floe. The remaining error is dominated by uncertainty in ice density. Provision of improved ice density data is therefore important for accurate retrieval of ice thickness from CryoSat-2 data. |
format |
Text |
author |
Alexandrov, V. Sandven, S. Wahlin, J. Johannessen, O. M. |
spellingShingle |
Alexandrov, V. Sandven, S. Wahlin, J. Johannessen, O. M. The relation between sea ice thickness and freeboard in the Arctic |
author_facet |
Alexandrov, V. Sandven, S. Wahlin, J. Johannessen, O. M. |
author_sort |
Alexandrov, V. |
title |
The relation between sea ice thickness and freeboard in the Arctic |
title_short |
The relation between sea ice thickness and freeboard in the Arctic |
title_full |
The relation between sea ice thickness and freeboard in the Arctic |
title_fullStr |
The relation between sea ice thickness and freeboard in the Arctic |
title_full_unstemmed |
The relation between sea ice thickness and freeboard in the Arctic |
title_sort |
relation between sea ice thickness and freeboard in the arctic |
publishDate |
2018 |
url |
https://doi.org/10.5194/tc-4-373-2010 https://tc.copernicus.org/articles/4/373/2010/ |
long_lat |
ENVELOPE(166.083,166.083,62.917,62.917) |
geographic |
Arctic Sever |
geographic_facet |
Arctic Sever |
genre |
Arctic Sea ice |
genre_facet |
Arctic Sea ice |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-4-373-2010 https://tc.copernicus.org/articles/4/373/2010/ |
op_doi |
https://doi.org/10.5194/tc-4-373-2010 |
container_title |
The Cryosphere |
container_volume |
4 |
container_issue |
3 |
container_start_page |
373 |
op_container_end_page |
380 |
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1766332593420107776 |