Retrieval of the Absorption Coefficient of L-Band Radiation in Antarctica From SMOS Observations
International audience Microwave emissions at the L-band (1-2 GHz) in Antarctica are characterized by a significant contribution of ice layers at great depth, from hundreds to a thousand meters. Brightness temperatures, thus, could provide the internal temperature of the ice sheet. However, there ar...
Published in: | Remote Sensing |
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Main Authors: | , , , , , , |
Other Authors: | , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2018
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Subjects: | |
Online Access: | https://hal.science/hal-02374894 https://hal.science/hal-02374894/document https://hal.science/hal-02374894/file/remotesensing-10-01954.pdf https://doi.org/10.3390/rs10121954 |
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ftunivnantes:oai:HAL:hal-02374894v1 |
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openpolar |
institution |
Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
English |
topic |
passive microwave Band L SMOS Antarctica brightness temperature emissivity permittivity absorption coefficient [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology |
spellingShingle |
passive microwave Band L SMOS Antarctica brightness temperature emissivity permittivity absorption coefficient [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology Passalacqua, Olivier Picard, Ghislain Ritz, Catherine Leduc-Leballeur, Marion Quiquet, Aurélien Larue, Fanny Macelloni, Giovanni Retrieval of the Absorption Coefficient of L-Band Radiation in Antarctica From SMOS Observations |
topic_facet |
passive microwave Band L SMOS Antarctica brightness temperature emissivity permittivity absorption coefficient [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology |
description |
International audience Microwave emissions at the L-band (1-2 GHz) in Antarctica are characterized by a significant contribution of ice layers at great depth, from hundreds to a thousand meters. Brightness temperatures, thus, could provide the internal temperature of the ice sheet. However, there are two difficulties to overcome in developing an accurate retrieval algorithm. First, it is difficult to know precisely from which depths waves are emanating because the ice-absorption coefficient is uncertain at the L-band, despite several formulations proposed in the literature over the past few decades. Second, emissivity potentially varies in Antarctica due to remnant scattering in firn (or ice), even at the Brewster angle, and despite the low frequency, limiting the accuracy of the estimate of the physical temperature. Here, we present a retrieval method able to disentangle the absorption and emissivity effects from brightness temperature over the whole continent. We exploit the fact that scattering and absorption are controlled by different physical parameters and phenomena that can be considered as statistically independent. This independence provides a constraint to the retrieval method, that is then well-conditioned and solvable. Our results show that (1) the retrieved absorption agrees with the permittivity model proposed by Mätzler et al. (2006), and (2) emissivity shows significant variations, up to 6% over the continent, which are correlated with wind speed and accumulation patterns. A possible cause of this latter point is density heterogeneity and sastrugi buried in the firn. These two results are an important step forward for the accurate retrieval of internal temperature using low-frequency microwave radiometers. |
author2 |
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 ) 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 ) Institute of Applied Physics "Nello Carrara" (IFAC) Consiglio Nazionale delle Ricerche (CNR) Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE) Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS) Modélisation du climat (CLIM) Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Passalacqua, Olivier Picard, Ghislain Ritz, Catherine Leduc-Leballeur, Marion Quiquet, Aurélien Larue, Fanny Macelloni, Giovanni |
author_facet |
Passalacqua, Olivier Picard, Ghislain Ritz, Catherine Leduc-Leballeur, Marion Quiquet, Aurélien Larue, Fanny Macelloni, Giovanni |
author_sort |
Passalacqua, Olivier |
title |
Retrieval of the Absorption Coefficient of L-Band Radiation in Antarctica From SMOS Observations |
title_short |
Retrieval of the Absorption Coefficient of L-Band Radiation in Antarctica From SMOS Observations |
title_full |
Retrieval of the Absorption Coefficient of L-Band Radiation in Antarctica From SMOS Observations |
title_fullStr |
Retrieval of the Absorption Coefficient of L-Band Radiation in Antarctica From SMOS Observations |
title_full_unstemmed |
Retrieval of the Absorption Coefficient of L-Band Radiation in Antarctica From SMOS Observations |
title_sort |
retrieval of the absorption coefficient of l-band radiation in antarctica from smos observations |
publisher |
HAL CCSD |
publishDate |
2018 |
url |
https://hal.science/hal-02374894 https://hal.science/hal-02374894/document https://hal.science/hal-02374894/file/remotesensing-10-01954.pdf https://doi.org/10.3390/rs10121954 |
long_lat |
ENVELOPE(169.383,169.383,-72.950,-72.950) ENVELOPE(163.683,163.683,-74.617,-74.617) |
geographic |
Brewster Sastrugi |
geographic_facet |
Brewster Sastrugi |
genre |
Antarc* Antarctica Ice Sheet |
genre_facet |
Antarc* Antarctica Ice Sheet |
op_source |
ISSN: 2072-4292 Remote Sensing https://hal.science/hal-02374894 Remote Sensing, 2018, 10 (12), pp.1954. ⟨10.3390/rs10121954⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.3390/rs10121954 hal-02374894 https://hal.science/hal-02374894 https://hal.science/hal-02374894/document https://hal.science/hal-02374894/file/remotesensing-10-01954.pdf doi:10.3390/rs10121954 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.3390/rs10121954 |
container_title |
Remote Sensing |
container_volume |
10 |
container_issue |
12 |
container_start_page |
1954 |
_version_ |
1766188541885284352 |
spelling |
ftunivnantes:oai:HAL:hal-02374894v1 2023-05-15T13:43:24+02:00 Retrieval of the Absorption Coefficient of L-Band Radiation in Antarctica From SMOS Observations Passalacqua, Olivier Picard, Ghislain Ritz, Catherine Leduc-Leballeur, Marion Quiquet, Aurélien Larue, Fanny Macelloni, Giovanni 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 ) 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 ) Institute of Applied Physics "Nello Carrara" (IFAC) Consiglio Nazionale delle Ricerche (CNR) Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE) Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS) Modélisation du climat (CLIM) Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS) 2018-12 https://hal.science/hal-02374894 https://hal.science/hal-02374894/document https://hal.science/hal-02374894/file/remotesensing-10-01954.pdf https://doi.org/10.3390/rs10121954 en eng HAL CCSD MDPI info:eu-repo/semantics/altIdentifier/doi/10.3390/rs10121954 hal-02374894 https://hal.science/hal-02374894 https://hal.science/hal-02374894/document https://hal.science/hal-02374894/file/remotesensing-10-01954.pdf doi:10.3390/rs10121954 info:eu-repo/semantics/OpenAccess ISSN: 2072-4292 Remote Sensing https://hal.science/hal-02374894 Remote Sensing, 2018, 10 (12), pp.1954. ⟨10.3390/rs10121954⟩ passive microwave Band L SMOS Antarctica brightness temperature emissivity permittivity absorption coefficient [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology info:eu-repo/semantics/article Journal articles 2018 ftunivnantes https://doi.org/10.3390/rs10121954 2023-03-01T02:56:28Z International audience Microwave emissions at the L-band (1-2 GHz) in Antarctica are characterized by a significant contribution of ice layers at great depth, from hundreds to a thousand meters. Brightness temperatures, thus, could provide the internal temperature of the ice sheet. However, there are two difficulties to overcome in developing an accurate retrieval algorithm. First, it is difficult to know precisely from which depths waves are emanating because the ice-absorption coefficient is uncertain at the L-band, despite several formulations proposed in the literature over the past few decades. Second, emissivity potentially varies in Antarctica due to remnant scattering in firn (or ice), even at the Brewster angle, and despite the low frequency, limiting the accuracy of the estimate of the physical temperature. Here, we present a retrieval method able to disentangle the absorption and emissivity effects from brightness temperature over the whole continent. We exploit the fact that scattering and absorption are controlled by different physical parameters and phenomena that can be considered as statistically independent. This independence provides a constraint to the retrieval method, that is then well-conditioned and solvable. Our results show that (1) the retrieved absorption agrees with the permittivity model proposed by Mätzler et al. (2006), and (2) emissivity shows significant variations, up to 6% over the continent, which are correlated with wind speed and accumulation patterns. A possible cause of this latter point is density heterogeneity and sastrugi buried in the firn. These two results are an important step forward for the accurate retrieval of internal temperature using low-frequency microwave radiometers. Article in Journal/Newspaper Antarc* Antarctica Ice Sheet Université de Nantes: HAL-UNIV-NANTES Brewster ENVELOPE(169.383,169.383,-72.950,-72.950) Sastrugi ENVELOPE(163.683,163.683,-74.617,-74.617) Remote Sensing 10 12 1954 |