The 2018 North Greenland polynya observed by a newly introduced merged optical and passive microwave sea-ice concentration dataset
Observations of sea-ice concentration are available from satellites year-round and almost weather-independently using passive microwave radiometers at resolutions down to 5 km. Thermal infrared radiometers provide data with a resolution of 1 km but only under cloud-free conditions. We use the best o...
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Copernicus Publications
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00000656 2023-05-15T15:15:25+02:00 The 2018 North Greenland polynya observed by a newly introduced merged optical and passive microwave sea-ice concentration dataset Ludwig, Valentin Spreen, Gunnar Haas, Christian Istomina, Larysa Kauker, Frank Murashkin, Dmitrii 2019-07 electronic https://doi.org/10.5194/tc-13-2051-2019 https://noa.gwlb.de/receive/cop_mods_00000656 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00000621/tc-13-2051-2019.pdf https://tc.copernicus.org/articles/13/2051/2019/tc-13-2051-2019.pdf eng eng Copernicus Publications The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-13-2051-2019 https://noa.gwlb.de/receive/cop_mods_00000656 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00000621/tc-13-2051-2019.pdf https://tc.copernicus.org/articles/13/2051/2019/tc-13-2051-2019.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess CC-BY article Verlagsveröffentlichung article Text doc-type:article 2019 ftnonlinearchiv https://doi.org/10.5194/tc-13-2051-2019 2022-02-08T23:02:14Z Observations of sea-ice concentration are available from satellites year-round and almost weather-independently using passive microwave radiometers at resolutions down to 5 km. Thermal infrared radiometers provide data with a resolution of 1 km but only under cloud-free conditions. We use the best of the two satellite measurements and merge thermal infrared and passive microwave sea-ice concentrations. This yields a merged sea-ice concentration product combining the gap-free spatial coverage of the passive microwave sea-ice concentration and the 1 km resolution of the thermal infrared sea-ice concentration. The benefit of the merged product is demonstrated by observations of a polynya which opened north of Greenland in February 2018. We find that the merged sea-ice concentration product resolves leads at sea-ice concentrations between 60 % and 90 %. They are not resolved by the coarser passive microwave sea-ice concentration product. The benefit of the merged product is most pronounced during the formation of the polynya. Next, the environmental conditions during the polynya event are analysed. The polynya was caused by unusual southerly winds during which the sea ice drifted northward instead of southward as usual. The daily displacement was 50 % stronger than normal. The polynya was associated with a warm-air intrusion caused by a high-pressure system over the Eurasian Arctic. Surface air temperatures were slightly below 0 ∘C and thus more than 20 ∘C higher than normal. Two estimates of thermodynamic sea-ice growth yield sea-ice thicknesses of 60 and 65 cm at the end of March in the area opened by the polynya. This differed from airborne sea-ice thickness measurements, indicating that sea-ice growth processes in the polynya are complicated by rafting and ridging. A sea-ice volume of 33 km3 was produced thermodynamically. Article in Journal/Newspaper Arctic Greenland North Greenland Sea ice The Cryosphere Niedersächsisches Online-Archiv NOA Arctic Greenland The Cryosphere 13 7 2051 2073 |
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Open Polar |
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Niedersächsisches Online-Archiv NOA |
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English |
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article Verlagsveröffentlichung |
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article Verlagsveröffentlichung Ludwig, Valentin Spreen, Gunnar Haas, Christian Istomina, Larysa Kauker, Frank Murashkin, Dmitrii The 2018 North Greenland polynya observed by a newly introduced merged optical and passive microwave sea-ice concentration dataset |
topic_facet |
article Verlagsveröffentlichung |
description |
Observations of sea-ice concentration are available from satellites year-round and almost weather-independently using passive microwave radiometers at resolutions down to 5 km. Thermal infrared radiometers provide data with a resolution of 1 km but only under cloud-free conditions. We use the best of the two satellite measurements and merge thermal infrared and passive microwave sea-ice concentrations. This yields a merged sea-ice concentration product combining the gap-free spatial coverage of the passive microwave sea-ice concentration and the 1 km resolution of the thermal infrared sea-ice concentration. The benefit of the merged product is demonstrated by observations of a polynya which opened north of Greenland in February 2018. We find that the merged sea-ice concentration product resolves leads at sea-ice concentrations between 60 % and 90 %. They are not resolved by the coarser passive microwave sea-ice concentration product. The benefit of the merged product is most pronounced during the formation of the polynya. Next, the environmental conditions during the polynya event are analysed. The polynya was caused by unusual southerly winds during which the sea ice drifted northward instead of southward as usual. The daily displacement was 50 % stronger than normal. The polynya was associated with a warm-air intrusion caused by a high-pressure system over the Eurasian Arctic. Surface air temperatures were slightly below 0 ∘C and thus more than 20 ∘C higher than normal. Two estimates of thermodynamic sea-ice growth yield sea-ice thicknesses of 60 and 65 cm at the end of March in the area opened by the polynya. This differed from airborne sea-ice thickness measurements, indicating that sea-ice growth processes in the polynya are complicated by rafting and ridging. A sea-ice volume of 33 km3 was produced thermodynamically. |
format |
Article in Journal/Newspaper |
author |
Ludwig, Valentin Spreen, Gunnar Haas, Christian Istomina, Larysa Kauker, Frank Murashkin, Dmitrii |
author_facet |
Ludwig, Valentin Spreen, Gunnar Haas, Christian Istomina, Larysa Kauker, Frank Murashkin, Dmitrii |
author_sort |
Ludwig, Valentin |
title |
The 2018 North Greenland polynya observed by a newly introduced merged optical and passive microwave sea-ice concentration dataset |
title_short |
The 2018 North Greenland polynya observed by a newly introduced merged optical and passive microwave sea-ice concentration dataset |
title_full |
The 2018 North Greenland polynya observed by a newly introduced merged optical and passive microwave sea-ice concentration dataset |
title_fullStr |
The 2018 North Greenland polynya observed by a newly introduced merged optical and passive microwave sea-ice concentration dataset |
title_full_unstemmed |
The 2018 North Greenland polynya observed by a newly introduced merged optical and passive microwave sea-ice concentration dataset |
title_sort |
2018 north greenland polynya observed by a newly introduced merged optical and passive microwave sea-ice concentration dataset |
publisher |
Copernicus Publications |
publishDate |
2019 |
url |
https://doi.org/10.5194/tc-13-2051-2019 https://noa.gwlb.de/receive/cop_mods_00000656 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00000621/tc-13-2051-2019.pdf https://tc.copernicus.org/articles/13/2051/2019/tc-13-2051-2019.pdf |
geographic |
Arctic Greenland |
geographic_facet |
Arctic Greenland |
genre |
Arctic Greenland North Greenland Sea ice The Cryosphere |
genre_facet |
Arctic Greenland North Greenland Sea ice The Cryosphere |
op_relation |
The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-13-2051-2019 https://noa.gwlb.de/receive/cop_mods_00000656 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00000621/tc-13-2051-2019.pdf https://tc.copernicus.org/articles/13/2051/2019/tc-13-2051-2019.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/tc-13-2051-2019 |
container_title |
The Cryosphere |
container_volume |
13 |
container_issue |
7 |
container_start_page |
2051 |
op_container_end_page |
2073 |
_version_ |
1766345784916180992 |