A contribution to Antarctic climate study : Variability of surface melting between 1979 and 1999 from microwave remote sensors. And parametrisation of the stable atmospheric boundary layer.
In the first part of this report, partial summer melting of antarctic snow, which significantly affects the microwave emissivity of the surface, is identified and counted over 18 years in the 20-year period 1980-1999. To process the satellite data, an algorithm that adapts to the spatial and interan...
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Other Authors: | , , , , |
Format: | Doctoral or Postdoctoral Thesis |
Language: | French |
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HAL CCSD
2002
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Online Access: | https://tel.archives-ouvertes.fr/tel-00755689 https://tel.archives-ouvertes.fr/tel-00755689/document https://tel.archives-ouvertes.fr/tel-00755689/file/These-Torinesi-2002.pdf |
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ftccsdartic:oai:HAL:tel-00755689v1 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
French |
topic |
Antarctique Télédétection Micro-ondes Température de brillance Fonte de surface Variabilité climatique Modèle de la circulation générale de l'atmosphère Paramétrisation Couche limite atmosphérique Stratification stable Flux turbulents [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology |
spellingShingle |
Antarctique Télédétection Micro-ondes Température de brillance Fonte de surface Variabilité climatique Modèle de la circulation générale de l'atmosphère Paramétrisation Couche limite atmosphérique Stratification stable Flux turbulents [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology Torinesi, Olivier A contribution to Antarctic climate study : Variability of surface melting between 1979 and 1999 from microwave remote sensors. And parametrisation of the stable atmospheric boundary layer. |
topic_facet |
Antarctique Télédétection Micro-ondes Température de brillance Fonte de surface Variabilité climatique Modèle de la circulation générale de l'atmosphère Paramétrisation Couche limite atmosphérique Stratification stable Flux turbulents [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology |
description |
In the first part of this report, partial summer melting of antarctic snow, which significantly affects the microwave emissivity of the surface, is identified and counted over 18 years in the 20-year period 1980-1999. To process the satellite data, an algorithm that adapts to the spatial and interannual variability of the mean brightness temperature of snow was developped. The cumulated product of the surface area affected by melting and the duration of the melting event, called Cumulative Melting Surface (CMS), is one of the three melt indices defined and discussed here. On average over the last 20 years, the Antarctic CMS has decreased by 1.8 ± 1 % year-l, a result which is consistent with a mean January cooling of the continent, recently identified by others from infrared satellite data. In addition, the interannual signature of the Antarctic Oscillation (AO), and possibly of the Southern Oscillation (ENSO), are found in the melt indices. Atmospheric general circulation models (AG CM) are still insufficiently advanced to adequately describe ail polar climate charateristics. In particular, the surface energy balance, and consequently snow melt, is incorrectly simulated by the AGCM LMDz. To improve this, a non local parametrisation of surface turbulent fluxes in highly stable and long-lived boundary layers (typical of the long antarctic polar night) is tested. The parametrisation accounts for vertical propagation of gravit y waves from the free troposphere, creating intermittent turbulence in the stable layer. Despite a high interannual climatic variability, the surface temperature and wind speed are generally better simulated on the continent, but a decoupling between the surface and the first vertical level appears near Vostok. Dans une première partie de ce travail, la fonte estivale partielle de la neige antarctique, qui affecte fortement l'émissivité micro-onde de la surface, est identifiée et comptabilisée au cours de 18 années sur la période 1980-1999. Pour cela, un algorithme de traitement des données ... |
author2 |
Laboratoire de glaciologie et géophysique de l'environnement (LGGE) Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG) Université Joseph Fourier - Grenoble 1 (UJF)-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 Joseph Fourier - Grenoble 1 (UJF)-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 Joseph-Fourier - Grenoble I Michel Fily |
format |
Doctoral or Postdoctoral Thesis |
author |
Torinesi, Olivier |
author_facet |
Torinesi, Olivier |
author_sort |
Torinesi, Olivier |
title |
A contribution to Antarctic climate study : Variability of surface melting between 1979 and 1999 from microwave remote sensors. And parametrisation of the stable atmospheric boundary layer. |
title_short |
A contribution to Antarctic climate study : Variability of surface melting between 1979 and 1999 from microwave remote sensors. And parametrisation of the stable atmospheric boundary layer. |
title_full |
A contribution to Antarctic climate study : Variability of surface melting between 1979 and 1999 from microwave remote sensors. And parametrisation of the stable atmospheric boundary layer. |
title_fullStr |
A contribution to Antarctic climate study : Variability of surface melting between 1979 and 1999 from microwave remote sensors. And parametrisation of the stable atmospheric boundary layer. |
title_full_unstemmed |
A contribution to Antarctic climate study : Variability of surface melting between 1979 and 1999 from microwave remote sensors. And parametrisation of the stable atmospheric boundary layer. |
title_sort |
contribution to antarctic climate study : variability of surface melting between 1979 and 1999 from microwave remote sensors. and parametrisation of the stable atmospheric boundary layer. |
publisher |
HAL CCSD |
publishDate |
2002 |
url |
https://tel.archives-ouvertes.fr/tel-00755689 https://tel.archives-ouvertes.fr/tel-00755689/document https://tel.archives-ouvertes.fr/tel-00755689/file/These-Torinesi-2002.pdf |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Antarctique* polar night |
genre_facet |
Antarc* Antarctic Antarctique* polar night |
op_source |
https://tel.archives-ouvertes.fr/tel-00755689 Glaciologie. Université Joseph-Fourier - Grenoble I, 2002. Français |
op_relation |
tel-00755689 https://tel.archives-ouvertes.fr/tel-00755689 https://tel.archives-ouvertes.fr/tel-00755689/document https://tel.archives-ouvertes.fr/tel-00755689/file/These-Torinesi-2002.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1766274960224944128 |
spelling |
ftccsdartic:oai:HAL:tel-00755689v1 2023-05-15T14:04:01+02:00 A contribution to Antarctic climate study : Variability of surface melting between 1979 and 1999 from microwave remote sensors. And parametrisation of the stable atmospheric boundary layer. Contribution à l'étude du climat antarctique : variabilité de la fonte de surface par télédétection micro-onde entre 1979 et 1999 et paramétrisation de la couche limite atmosphérique stable Torinesi, Olivier Laboratoire de glaciologie et géophysique de l'environnement (LGGE) Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG) Université Joseph Fourier - Grenoble 1 (UJF)-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 Joseph Fourier - Grenoble 1 (UJF)-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 Joseph-Fourier - Grenoble I Michel Fily 2002-06-26 https://tel.archives-ouvertes.fr/tel-00755689 https://tel.archives-ouvertes.fr/tel-00755689/document https://tel.archives-ouvertes.fr/tel-00755689/file/These-Torinesi-2002.pdf fr fre HAL CCSD tel-00755689 https://tel.archives-ouvertes.fr/tel-00755689 https://tel.archives-ouvertes.fr/tel-00755689/document https://tel.archives-ouvertes.fr/tel-00755689/file/These-Torinesi-2002.pdf info:eu-repo/semantics/OpenAccess https://tel.archives-ouvertes.fr/tel-00755689 Glaciologie. Université Joseph-Fourier - Grenoble I, 2002. Français Antarctique Télédétection Micro-ondes Température de brillance Fonte de surface Variabilité climatique Modèle de la circulation générale de l'atmosphère Paramétrisation Couche limite atmosphérique Stratification stable Flux turbulents [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology info:eu-repo/semantics/doctoralThesis Theses 2002 ftccsdartic 2021-10-24T15:46:19Z In the first part of this report, partial summer melting of antarctic snow, which significantly affects the microwave emissivity of the surface, is identified and counted over 18 years in the 20-year period 1980-1999. To process the satellite data, an algorithm that adapts to the spatial and interannual variability of the mean brightness temperature of snow was developped. The cumulated product of the surface area affected by melting and the duration of the melting event, called Cumulative Melting Surface (CMS), is one of the three melt indices defined and discussed here. On average over the last 20 years, the Antarctic CMS has decreased by 1.8 ± 1 % year-l, a result which is consistent with a mean January cooling of the continent, recently identified by others from infrared satellite data. In addition, the interannual signature of the Antarctic Oscillation (AO), and possibly of the Southern Oscillation (ENSO), are found in the melt indices. Atmospheric general circulation models (AG CM) are still insufficiently advanced to adequately describe ail polar climate charateristics. In particular, the surface energy balance, and consequently snow melt, is incorrectly simulated by the AGCM LMDz. To improve this, a non local parametrisation of surface turbulent fluxes in highly stable and long-lived boundary layers (typical of the long antarctic polar night) is tested. The parametrisation accounts for vertical propagation of gravit y waves from the free troposphere, creating intermittent turbulence in the stable layer. Despite a high interannual climatic variability, the surface temperature and wind speed are generally better simulated on the continent, but a decoupling between the surface and the first vertical level appears near Vostok. Dans une première partie de ce travail, la fonte estivale partielle de la neige antarctique, qui affecte fortement l'émissivité micro-onde de la surface, est identifiée et comptabilisée au cours de 18 années sur la période 1980-1999. Pour cela, un algorithme de traitement des données ... Doctoral or Postdoctoral Thesis Antarc* Antarctic Antarctique* polar night Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Antarctic The Antarctic |