Seasonal variations of the backscattering coefficient measured by radar altimeters over the Antarctic Ice Sheet
International audience Spaceborne radar altimeters are a valuable tool for observing the Antarctic Ice Sheet. The radar wave interaction with the snow provides information on both the surface and the subsurface of the snowpack due to its dependence on the snow properties. However, the penetration of...
Published in: | The Cryosphere |
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Main Authors: | , , |
Other Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2018
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Online Access: | https://insu.hal.science/insu-03706506 https://insu.hal.science/insu-03706506/document https://insu.hal.science/insu-03706506/file/tc-12-1767-2018.pdf https://doi.org/10.5194/tc-12-1767-2018 |
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ftunigrenoble:oai:HAL:insu-03706506v1 |
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openpolar |
institution |
Open Polar |
collection |
Université Grenoble Alpes: HAL |
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ftunigrenoble |
language |
English |
topic |
[SDU]Sciences of the Universe [physics] |
spellingShingle |
[SDU]Sciences of the Universe [physics] Ibrahime Adodo, Fifi Remy, Frédérique Picard, Ghislain Seasonal variations of the backscattering coefficient measured by radar altimeters over the Antarctic Ice Sheet |
topic_facet |
[SDU]Sciences of the Universe [physics] |
description |
International audience Spaceborne radar altimeters are a valuable tool for observing the Antarctic Ice Sheet. The radar wave interaction with the snow provides information on both the surface and the subsurface of the snowpack due to its dependence on the snow properties. However, the penetration of the radar wave within the snowpack also induces a negative bias on the estimated surface elevation. Empirical corrections of this space- and time-varying bias are usually based on the backscattering coefficient variability. We investigate the spatial and seasonal variations of the backscattering coefficient at the S (3.2 GHz ∼ 9.4 cm), Ku (13.6 GHz ∼ 2.3 cm) and Ka (37 GHz ∼ 0.8 cm) bands. We identified that the backscattering coefficient at Ku band reaches a maximum in winter in part of the continent (Region 1) and in the summer in the remaining (Region 2), while the evolution at other frequencies is relatively uniform over the whole continent. To explain this contrasting behavior between frequencies and between regions, we studied the sensitivity of the backscattering coefficient at three frequencies to several parameters (surface snow density, snow temperature and snow grain size) using an electromagnetic model. The results show that the seasonal cycle of the backscattering coefficient at Ka frequency is dominated by the volume echo and is mainly driven by snow temperature evolution everywhere. In contrast, at S band, the cycle is dominated by the surface echo. At Ku band, the seasonal cycle is dominated by the volume echo in Region 1 and by the surface echo in Region 2. This investigation provides new information on the seasonal dynamics of the Antarctic Ice Sheet surface and provides new clues to build more accurate corrections of the radar altimeter surface elevation signal in the future. |
author2 |
Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS) Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS) Institut des Géosciences de l’Environnement (IGE) Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ) |
format |
Article in Journal/Newspaper |
author |
Ibrahime Adodo, Fifi Remy, Frédérique Picard, Ghislain |
author_facet |
Ibrahime Adodo, Fifi Remy, Frédérique Picard, Ghislain |
author_sort |
Ibrahime Adodo, Fifi |
title |
Seasonal variations of the backscattering coefficient measured by radar altimeters over the Antarctic Ice Sheet |
title_short |
Seasonal variations of the backscattering coefficient measured by radar altimeters over the Antarctic Ice Sheet |
title_full |
Seasonal variations of the backscattering coefficient measured by radar altimeters over the Antarctic Ice Sheet |
title_fullStr |
Seasonal variations of the backscattering coefficient measured by radar altimeters over the Antarctic Ice Sheet |
title_full_unstemmed |
Seasonal variations of the backscattering coefficient measured by radar altimeters over the Antarctic Ice Sheet |
title_sort |
seasonal variations of the backscattering coefficient measured by radar altimeters over the antarctic ice sheet |
publisher |
HAL CCSD |
publishDate |
2018 |
url |
https://insu.hal.science/insu-03706506 https://insu.hal.science/insu-03706506/document https://insu.hal.science/insu-03706506/file/tc-12-1767-2018.pdf https://doi.org/10.5194/tc-12-1767-2018 |
genre |
Antarc* Antarctic Ice Sheet The Cryosphere |
genre_facet |
Antarc* Antarctic Ice Sheet The Cryosphere |
op_source |
ISSN: 1994-0424 EISSN: 1994-0416 The Cryosphere https://insu.hal.science/insu-03706506 The Cryosphere, 2018, 12, pp.1767-1778. ⟨10.5194/tc-12-1767-2018⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-12-1767-2018 insu-03706506 https://insu.hal.science/insu-03706506 https://insu.hal.science/insu-03706506/document https://insu.hal.science/insu-03706506/file/tc-12-1767-2018.pdf BIBCODE: 2018TCry.12.1767I doi:10.5194/tc-12-1767-2018 |
op_rights |
http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.5194/tc-12-1767-2018 |
container_title |
The Cryosphere |
container_volume |
12 |
container_issue |
5 |
container_start_page |
1767 |
op_container_end_page |
1778 |
_version_ |
1810488373638332416 |
spelling |
ftunigrenoble:oai:HAL:insu-03706506v1 2024-09-15T17:42:02+00:00 Seasonal variations of the backscattering coefficient measured by radar altimeters over the Antarctic Ice Sheet Ibrahime Adodo, Fifi Remy, Frédérique Picard, Ghislain Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS) Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS) Institut des Géosciences de l’Environnement (IGE) Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ) 2018 https://insu.hal.science/insu-03706506 https://insu.hal.science/insu-03706506/document https://insu.hal.science/insu-03706506/file/tc-12-1767-2018.pdf https://doi.org/10.5194/tc-12-1767-2018 en eng HAL CCSD Copernicus info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-12-1767-2018 insu-03706506 https://insu.hal.science/insu-03706506 https://insu.hal.science/insu-03706506/document https://insu.hal.science/insu-03706506/file/tc-12-1767-2018.pdf BIBCODE: 2018TCry.12.1767I doi:10.5194/tc-12-1767-2018 http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess ISSN: 1994-0424 EISSN: 1994-0416 The Cryosphere https://insu.hal.science/insu-03706506 The Cryosphere, 2018, 12, pp.1767-1778. ⟨10.5194/tc-12-1767-2018⟩ [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2018 ftunigrenoble https://doi.org/10.5194/tc-12-1767-2018 2024-07-15T23:41:00Z International audience Spaceborne radar altimeters are a valuable tool for observing the Antarctic Ice Sheet. The radar wave interaction with the snow provides information on both the surface and the subsurface of the snowpack due to its dependence on the snow properties. However, the penetration of the radar wave within the snowpack also induces a negative bias on the estimated surface elevation. Empirical corrections of this space- and time-varying bias are usually based on the backscattering coefficient variability. We investigate the spatial and seasonal variations of the backscattering coefficient at the S (3.2 GHz ∼ 9.4 cm), Ku (13.6 GHz ∼ 2.3 cm) and Ka (37 GHz ∼ 0.8 cm) bands. We identified that the backscattering coefficient at Ku band reaches a maximum in winter in part of the continent (Region 1) and in the summer in the remaining (Region 2), while the evolution at other frequencies is relatively uniform over the whole continent. To explain this contrasting behavior between frequencies and between regions, we studied the sensitivity of the backscattering coefficient at three frequencies to several parameters (surface snow density, snow temperature and snow grain size) using an electromagnetic model. The results show that the seasonal cycle of the backscattering coefficient at Ka frequency is dominated by the volume echo and is mainly driven by snow temperature evolution everywhere. In contrast, at S band, the cycle is dominated by the surface echo. At Ku band, the seasonal cycle is dominated by the volume echo in Region 1 and by the surface echo in Region 2. This investigation provides new information on the seasonal dynamics of the Antarctic Ice Sheet surface and provides new clues to build more accurate corrections of the radar altimeter surface elevation signal in the future. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet The Cryosphere Université Grenoble Alpes: HAL The Cryosphere 12 5 1767 1778 |