Analyzing and modeling the SMOS spatial variations in the East Antarctic Plateau
International audience The SMOS brightness temperature (TB) collected on the East Antarctic Plateau revealed spatial signatures at L-band that have never before been observed when only higher-frequency passive microwave observations were available, and this has opened up a new field of research. Bec...
Published in: | Remote Sensing of Environment |
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Main Authors: | , , , , |
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Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2016
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Online Access: | https://insu.hal.science/insu-01387307 https://doi.org/10.1016/j.rse.2016.02.037 |
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Institut national des sciences de l'Univers: HAL-INSU |
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English |
topic |
Antarctica SMOS Microwave emission model Ice sheet temperature [SDE]Environmental Sciences |
spellingShingle |
Antarctica SMOS Microwave emission model Ice sheet temperature [SDE]Environmental Sciences Macelloni, Giovanni Leduc-Leballeur, Marion Brogionia, Marco Ritz, Catherine Picard, Ghislain Analyzing and modeling the SMOS spatial variations in the East Antarctic Plateau |
topic_facet |
Antarctica SMOS Microwave emission model Ice sheet temperature [SDE]Environmental Sciences |
description |
International audience The SMOS brightness temperature (TB) collected on the East Antarctic Plateau revealed spatial signatures at L-band that have never before been observed when only higher-frequency passive microwave observations were available, and this has opened up a new field of research. Because of the much greater penetration depth, modeling the microwave ice sheet emission requires taking into account not only snow conditions on the surface, but should also include glaciological information. Even if the penetration depth of the L-band is not well known due to the uncertainty on the imaginary part of the ice permittivity, it is likely to be of the order of several hundreds of meters, which means that the temperature of the ice over a depth of nearly 1000 m influences the emission. Over such a depth, the temperature is related to both the surface conditions and to the ice sheet thickness, which in turn depends on the bedrock topography and on other glaciological variables. The present paper aims to provide a thorough theoretical explanation of the observed TB spatial variation close to the Brewster angle at vertical polarization, in order to limit the effect of surface and vertical density variability in the firn. In order to provide reliable inputs to the microwave emission models used for simulating TB data, an in-depth analysis of the temperature profiles was performed by means of glaciological models. The comparison between simulated and observed data over three transects totalling 2000 km in East Antarctica pointed out that, whereas the emission models are capable of explaining the TB spatial variations of several kelvins (0.7 and 2.9 K), they are unable to predict its absolute value correctly. This study also shows that the main limiting factor in simulating low-frequency microwave data is the uncertainty in the currently available imaginary part of the ice permittivity. |
author2 |
Istituto di Fisica Applicata "Nello Carrara" (IFAC) National Research Council of Italy Laboratoire de glaciologie et géophysique de l'environnement (LGGE) Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ) Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 )-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ) |
format |
Article in Journal/Newspaper |
author |
Macelloni, Giovanni Leduc-Leballeur, Marion Brogionia, Marco Ritz, Catherine Picard, Ghislain |
author_facet |
Macelloni, Giovanni Leduc-Leballeur, Marion Brogionia, Marco Ritz, Catherine Picard, Ghislain |
author_sort |
Macelloni, Giovanni |
title |
Analyzing and modeling the SMOS spatial variations in the East Antarctic Plateau |
title_short |
Analyzing and modeling the SMOS spatial variations in the East Antarctic Plateau |
title_full |
Analyzing and modeling the SMOS spatial variations in the East Antarctic Plateau |
title_fullStr |
Analyzing and modeling the SMOS spatial variations in the East Antarctic Plateau |
title_full_unstemmed |
Analyzing and modeling the SMOS spatial variations in the East Antarctic Plateau |
title_sort |
analyzing and modeling the smos spatial variations in the east antarctic plateau |
publisher |
HAL CCSD |
publishDate |
2016 |
url |
https://insu.hal.science/insu-01387307 https://doi.org/10.1016/j.rse.2016.02.037 |
genre |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet |
op_source |
ISSN: 0034-4257 EISSN: 1879-0704 Remote Sensing of Environment https://insu.hal.science/insu-01387307 Remote Sensing of Environment, 2016, 180 (july 2016), pp.193-204. ⟨10.1016/j.rse.2016.02.037⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.rse.2016.02.037 insu-01387307 https://insu.hal.science/insu-01387307 doi:10.1016/j.rse.2016.02.037 |
op_doi |
https://doi.org/10.1016/j.rse.2016.02.037 |
container_title |
Remote Sensing of Environment |
container_volume |
180 |
container_start_page |
193 |
op_container_end_page |
204 |
_version_ |
1797571302353010688 |
spelling |
ftinsu:oai:HAL:insu-01387307v1 2024-04-28T07:58:43+00:00 Analyzing and modeling the SMOS spatial variations in the East Antarctic Plateau Macelloni, Giovanni Leduc-Leballeur, Marion Brogionia, Marco Ritz, Catherine Picard, Ghislain Istituto di Fisica Applicata "Nello Carrara" (IFAC) National Research Council of Italy Laboratoire de glaciologie et géophysique de l'environnement (LGGE) Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ) Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 )-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ) 2016 https://insu.hal.science/insu-01387307 https://doi.org/10.1016/j.rse.2016.02.037 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.rse.2016.02.037 insu-01387307 https://insu.hal.science/insu-01387307 doi:10.1016/j.rse.2016.02.037 ISSN: 0034-4257 EISSN: 1879-0704 Remote Sensing of Environment https://insu.hal.science/insu-01387307 Remote Sensing of Environment, 2016, 180 (july 2016), pp.193-204. ⟨10.1016/j.rse.2016.02.037⟩ Antarctica SMOS Microwave emission model Ice sheet temperature [SDE]Environmental Sciences info:eu-repo/semantics/article Journal articles 2016 ftinsu https://doi.org/10.1016/j.rse.2016.02.037 2024-04-05T00:48:45Z International audience The SMOS brightness temperature (TB) collected on the East Antarctic Plateau revealed spatial signatures at L-band that have never before been observed when only higher-frequency passive microwave observations were available, and this has opened up a new field of research. Because of the much greater penetration depth, modeling the microwave ice sheet emission requires taking into account not only snow conditions on the surface, but should also include glaciological information. Even if the penetration depth of the L-band is not well known due to the uncertainty on the imaginary part of the ice permittivity, it is likely to be of the order of several hundreds of meters, which means that the temperature of the ice over a depth of nearly 1000 m influences the emission. Over such a depth, the temperature is related to both the surface conditions and to the ice sheet thickness, which in turn depends on the bedrock topography and on other glaciological variables. The present paper aims to provide a thorough theoretical explanation of the observed TB spatial variation close to the Brewster angle at vertical polarization, in order to limit the effect of surface and vertical density variability in the firn. In order to provide reliable inputs to the microwave emission models used for simulating TB data, an in-depth analysis of the temperature profiles was performed by means of glaciological models. The comparison between simulated and observed data over three transects totalling 2000 km in East Antarctica pointed out that, whereas the emission models are capable of explaining the TB spatial variations of several kelvins (0.7 and 2.9 K), they are unable to predict its absolute value correctly. This study also shows that the main limiting factor in simulating low-frequency microwave data is the uncertainty in the currently available imaginary part of the ice permittivity. Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica Ice Sheet Institut national des sciences de l'Univers: HAL-INSU Remote Sensing of Environment 180 193 204 |