Latest Altimetry-Based Sea Ice Freeboard and Volume Inter-Annual Variability in the Antarctic over 2003–2020
The relatively stable conditions of the sea ice cover in the Antarctic, observed for almost 40 years, seem to be changing recently. Therefore, it is essential to provide sea ice thickness (SIT) and volume (SIV) estimates in order to anticipate potential multi-scale changes in the Antarctic sea ice....
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ftmdpi:oai:mdpi.com:/2072-4292/14/19/4741/ 2023-08-20T04:01:01+02:00 Latest Altimetry-Based Sea Ice Freeboard and Volume Inter-Annual Variability in the Antarctic over 2003–2020 Florent Garnier Marion Bocquet Sara Fleury Jérôme Bouffard Michel Tsamados Frédérique Remy Gilles Garric Aliette Chenal agris 2022-09-22 application/pdf https://doi.org/10.3390/rs14194741 EN eng Multidisciplinary Digital Publishing Institute https://dx.doi.org/10.3390/rs14194741 https://creativecommons.org/licenses/by/4.0/ Remote Sensing; Volume 14; Issue 19; Pages: 4741 sea ice thickness sea ice volume CryoSat-2 envisat climate change Text 2022 ftmdpi https://doi.org/10.3390/rs14194741 2023-08-01T06:35:06Z The relatively stable conditions of the sea ice cover in the Antarctic, observed for almost 40 years, seem to be changing recently. Therefore, it is essential to provide sea ice thickness (SIT) and volume (SIV) estimates in order to anticipate potential multi-scale changes in the Antarctic sea ice. For that purpose, the main objectives of this work are: (1) to assess a new sea ice freeboard, thickness and volume altimetry dataset over 2003–2020 and (2) to identify first order impacts of the sea ice recent conditions. To produce these series, we use a neuronal network to calibrate Envisat radar freeboards onto CryoSat-2 (CS2). This method addresses the impacts of surface roughness on Low Resolution Mode (LRM) measurements. During the 2011 common flight period, we found a mean deviation between Envisat and CryoSat-2 radar freeboards by about 0.5 cm. Using the Advanced Microwave Scanning Radiometer (AMSR) and the dual-frequency Altimetric Snow Depth (ASD) data, our solutions are compared with the Upward looking sonar (ULS) draft data, some in-situ measurement of the SIMBA campaign, the total freeboards of 6 Operation Ice Bridge (OIB) missions and ICESat-2 total freeboards. Over 2003–2020, the global mean radar freeboard decreased by about −14% per decade and the SIT and SIV by about −10% per decade (considering a snow depth climatology). This is marked by a slight increase through 2015, which is directly followed by a strong decrease in 2016. Thereafter, freeboards generally remained low and even continued to decrease in some regions such as the Weddell sea. Considering the 2013–2020 period, for which the ASD data are available, radar freeboards and SIT decreased by about −40% per decade. The SIV decreased by about −60% per decade. After 2016, the low SIT values contrast with the sea ice extent that has rather increased again, reaching near-average values in winter 2020. The regional analysis underlines that such thinning (from 2016) occurs in all regions except the Amundsen-Bellingshausen sea sector. Meanwhile, we ... Text Antarc* Antarctic Bellingshausen Sea Sea ice Weddell Sea MDPI Open Access Publishing Antarctic The Antarctic Weddell Sea Bellingshausen Sea Weddell Remote Sensing 14 19 4741 |
institution |
Open Polar |
collection |
MDPI Open Access Publishing |
op_collection_id |
ftmdpi |
language |
English |
topic |
sea ice thickness sea ice volume CryoSat-2 envisat climate change |
spellingShingle |
sea ice thickness sea ice volume CryoSat-2 envisat climate change Florent Garnier Marion Bocquet Sara Fleury Jérôme Bouffard Michel Tsamados Frédérique Remy Gilles Garric Aliette Chenal Latest Altimetry-Based Sea Ice Freeboard and Volume Inter-Annual Variability in the Antarctic over 2003–2020 |
topic_facet |
sea ice thickness sea ice volume CryoSat-2 envisat climate change |
description |
The relatively stable conditions of the sea ice cover in the Antarctic, observed for almost 40 years, seem to be changing recently. Therefore, it is essential to provide sea ice thickness (SIT) and volume (SIV) estimates in order to anticipate potential multi-scale changes in the Antarctic sea ice. For that purpose, the main objectives of this work are: (1) to assess a new sea ice freeboard, thickness and volume altimetry dataset over 2003–2020 and (2) to identify first order impacts of the sea ice recent conditions. To produce these series, we use a neuronal network to calibrate Envisat radar freeboards onto CryoSat-2 (CS2). This method addresses the impacts of surface roughness on Low Resolution Mode (LRM) measurements. During the 2011 common flight period, we found a mean deviation between Envisat and CryoSat-2 radar freeboards by about 0.5 cm. Using the Advanced Microwave Scanning Radiometer (AMSR) and the dual-frequency Altimetric Snow Depth (ASD) data, our solutions are compared with the Upward looking sonar (ULS) draft data, some in-situ measurement of the SIMBA campaign, the total freeboards of 6 Operation Ice Bridge (OIB) missions and ICESat-2 total freeboards. Over 2003–2020, the global mean radar freeboard decreased by about −14% per decade and the SIT and SIV by about −10% per decade (considering a snow depth climatology). This is marked by a slight increase through 2015, which is directly followed by a strong decrease in 2016. Thereafter, freeboards generally remained low and even continued to decrease in some regions such as the Weddell sea. Considering the 2013–2020 period, for which the ASD data are available, radar freeboards and SIT decreased by about −40% per decade. The SIV decreased by about −60% per decade. After 2016, the low SIT values contrast with the sea ice extent that has rather increased again, reaching near-average values in winter 2020. The regional analysis underlines that such thinning (from 2016) occurs in all regions except the Amundsen-Bellingshausen sea sector. Meanwhile, we ... |
format |
Text |
author |
Florent Garnier Marion Bocquet Sara Fleury Jérôme Bouffard Michel Tsamados Frédérique Remy Gilles Garric Aliette Chenal |
author_facet |
Florent Garnier Marion Bocquet Sara Fleury Jérôme Bouffard Michel Tsamados Frédérique Remy Gilles Garric Aliette Chenal |
author_sort |
Florent Garnier |
title |
Latest Altimetry-Based Sea Ice Freeboard and Volume Inter-Annual Variability in the Antarctic over 2003–2020 |
title_short |
Latest Altimetry-Based Sea Ice Freeboard and Volume Inter-Annual Variability in the Antarctic over 2003–2020 |
title_full |
Latest Altimetry-Based Sea Ice Freeboard and Volume Inter-Annual Variability in the Antarctic over 2003–2020 |
title_fullStr |
Latest Altimetry-Based Sea Ice Freeboard and Volume Inter-Annual Variability in the Antarctic over 2003–2020 |
title_full_unstemmed |
Latest Altimetry-Based Sea Ice Freeboard and Volume Inter-Annual Variability in the Antarctic over 2003–2020 |
title_sort |
latest altimetry-based sea ice freeboard and volume inter-annual variability in the antarctic over 2003–2020 |
publisher |
Multidisciplinary Digital Publishing Institute |
publishDate |
2022 |
url |
https://doi.org/10.3390/rs14194741 |
op_coverage |
agris |
geographic |
Antarctic The Antarctic Weddell Sea Bellingshausen Sea Weddell |
geographic_facet |
Antarctic The Antarctic Weddell Sea Bellingshausen Sea Weddell |
genre |
Antarc* Antarctic Bellingshausen Sea Sea ice Weddell Sea |
genre_facet |
Antarc* Antarctic Bellingshausen Sea Sea ice Weddell Sea |
op_source |
Remote Sensing; Volume 14; Issue 19; Pages: 4741 |
op_relation |
https://dx.doi.org/10.3390/rs14194741 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3390/rs14194741 |
container_title |
Remote Sensing |
container_volume |
14 |
container_issue |
19 |
container_start_page |
4741 |
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1774722064468410368 |