Joined data/modelling study of the dynamics of the Antarctic Ice sheet evolution in the context of climate change.
Modelling of the polar ice sheets is important to reconstruct its past, understand its current state and predict its evolution in the context of the global warming and rising sea levels. There are numerous mechanisms involved in the dynamics of ice sheets and these are climate-dependent. In particul...
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Other Authors: | , , , , , |
Format: | Doctoral or Postdoctoral Thesis |
Language: | French |
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HAL CCSD
2011
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Subjects: | |
Online Access: | https://theses.hal.science/tel-00648409 https://theses.hal.science/tel-00648409/document https://theses.hal.science/tel-00648409/file/20863_NAVAS_2011_diffusion2.pdf |
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ftunivnantes:oai:HAL:tel-00648409v1 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
French |
topic |
Climate change Spatial data Balance flux Ice-sheet Ice-streams Changement climatique Données altimétriques Vitesse de bilan Calotte de glace Fleuves de glace [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
Climate change Spatial data Balance flux Ice-sheet Ice-streams Changement climatique Données altimétriques Vitesse de bilan Calotte de glace Fleuves de glace [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Navas, Giuliat Joined data/modelling study of the dynamics of the Antarctic Ice sheet evolution in the context of climate change. |
topic_facet |
Climate change Spatial data Balance flux Ice-sheet Ice-streams Changement climatique Données altimétriques Vitesse de bilan Calotte de glace Fleuves de glace [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
Modelling of the polar ice sheets is important to reconstruct its past, understand its current state and predict its evolution in the context of the global warming and rising sea levels. There are numerous mechanisms involved in the dynamics of ice sheets and these are climate-dependent. In particular there are two very important opposing mechanisms: the increase in the temperature which is supposed to lead to increased precipitation and thickening of the ice, and increased melting of the ice, which tends to reduce the mass of the ice sheets. To study these two mechanisms, we followed two approaches: characterize the ice sheets from direct observations (i.e., surface topography and ice flow velocities) or indirect observations (i.e., flow balance), and model it with GRISLI (Grenoble Ice Shelf and Land Ice), taking into account the dynamics of ice streams and their precise locations, to better understand the active mechanisms involved in the ice sheets. The subject of this thesis is to improve the modelling of ice sheets from the available data, especially those based on the first and second derivatives of the surface (slope and curvature respectively), and to link with the ice drainage, and velocity structure outcome. This data has allowed us to develop methods to model ice flows, subsequently introduce them into the GRISLI. We then made several sensitivity studies of the ice sheets, to localize ice streams, geothermal data flow and the parameters that control the slip and deformation of the ice. Finally, we compare the observed and modelled structures of the ice sheets, and show that model results are not far from the actual observed structures. La modélisation des calottes polaires est importante pour reconstruire l'état passé des calottes, comprendre l'état présent, et prévoir son évolution dans le contexte du réchauffement climatique et de l'élévation du niveau des mers. Les mécanismes qui interviennent dans la dynamique des calottes de glace et qui dépendent du climat sont nombreux, mais pour ... |
author2 |
Laboratoire de glaciologie et géophysique de l'environnement (LGGE) 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 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)-Centre National de la Recherche Scientifique (CNRS) Université de Grenoble Catherine Ritz Frédérique Rémy |
format |
Doctoral or Postdoctoral Thesis |
author |
Navas, Giuliat |
author_facet |
Navas, Giuliat |
author_sort |
Navas, Giuliat |
title |
Joined data/modelling study of the dynamics of the Antarctic Ice sheet evolution in the context of climate change. |
title_short |
Joined data/modelling study of the dynamics of the Antarctic Ice sheet evolution in the context of climate change. |
title_full |
Joined data/modelling study of the dynamics of the Antarctic Ice sheet evolution in the context of climate change. |
title_fullStr |
Joined data/modelling study of the dynamics of the Antarctic Ice sheet evolution in the context of climate change. |
title_full_unstemmed |
Joined data/modelling study of the dynamics of the Antarctic Ice sheet evolution in the context of climate change. |
title_sort |
joined data/modelling study of the dynamics of the antarctic ice sheet evolution in the context of climate change. |
publisher |
HAL CCSD |
publishDate |
2011 |
url |
https://theses.hal.science/tel-00648409 https://theses.hal.science/tel-00648409/document https://theses.hal.science/tel-00648409/file/20863_NAVAS_2011_diffusion2.pdf |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Antarctique* Ice Sheet Ice Shelf |
genre_facet |
Antarc* Antarctic Antarctique* Ice Sheet Ice Shelf |
op_source |
https://theses.hal.science/tel-00648409 Sciences de la Terre. Université de Grenoble, 2011. Français. ⟨NNT : 2011GRENU034⟩ |
op_relation |
NNT: 2011GRENU034 tel-00648409 https://theses.hal.science/tel-00648409 https://theses.hal.science/tel-00648409/document https://theses.hal.science/tel-00648409/file/20863_NAVAS_2011_diffusion2.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1766257176393809920 |
spelling |
ftunivnantes:oai:HAL:tel-00648409v1 2023-05-15T13:52:43+02:00 Joined data/modelling study of the dynamics of the Antarctic Ice sheet evolution in the context of climate change. Amélioration de la modélisation de la calotte de glace Antarctique à partir de la topographie de la surface Navas, Giuliat Laboratoire de glaciologie et géophysique de l'environnement (LGGE) 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 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)-Centre National de la Recherche Scientifique (CNRS) Université de Grenoble Catherine Ritz Frédérique Rémy 2011-11-22 https://theses.hal.science/tel-00648409 https://theses.hal.science/tel-00648409/document https://theses.hal.science/tel-00648409/file/20863_NAVAS_2011_diffusion2.pdf fr fre HAL CCSD NNT: 2011GRENU034 tel-00648409 https://theses.hal.science/tel-00648409 https://theses.hal.science/tel-00648409/document https://theses.hal.science/tel-00648409/file/20863_NAVAS_2011_diffusion2.pdf info:eu-repo/semantics/OpenAccess https://theses.hal.science/tel-00648409 Sciences de la Terre. Université de Grenoble, 2011. Français. ⟨NNT : 2011GRENU034⟩ Climate change Spatial data Balance flux Ice-sheet Ice-streams Changement climatique Données altimétriques Vitesse de bilan Calotte de glace Fleuves de glace [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/doctoralThesis Theses 2011 ftunivnantes 2023-03-08T00:15:32Z Modelling of the polar ice sheets is important to reconstruct its past, understand its current state and predict its evolution in the context of the global warming and rising sea levels. There are numerous mechanisms involved in the dynamics of ice sheets and these are climate-dependent. In particular there are two very important opposing mechanisms: the increase in the temperature which is supposed to lead to increased precipitation and thickening of the ice, and increased melting of the ice, which tends to reduce the mass of the ice sheets. To study these two mechanisms, we followed two approaches: characterize the ice sheets from direct observations (i.e., surface topography and ice flow velocities) or indirect observations (i.e., flow balance), and model it with GRISLI (Grenoble Ice Shelf and Land Ice), taking into account the dynamics of ice streams and their precise locations, to better understand the active mechanisms involved in the ice sheets. The subject of this thesis is to improve the modelling of ice sheets from the available data, especially those based on the first and second derivatives of the surface (slope and curvature respectively), and to link with the ice drainage, and velocity structure outcome. This data has allowed us to develop methods to model ice flows, subsequently introduce them into the GRISLI. We then made several sensitivity studies of the ice sheets, to localize ice streams, geothermal data flow and the parameters that control the slip and deformation of the ice. Finally, we compare the observed and modelled structures of the ice sheets, and show that model results are not far from the actual observed structures. La modélisation des calottes polaires est importante pour reconstruire l'état passé des calottes, comprendre l'état présent, et prévoir son évolution dans le contexte du réchauffement climatique et de l'élévation du niveau des mers. Les mécanismes qui interviennent dans la dynamique des calottes de glace et qui dépendent du climat sont nombreux, mais pour ... Doctoral or Postdoctoral Thesis Antarc* Antarctic Antarctique* Ice Sheet Ice Shelf Université de Nantes: HAL-UNIV-NANTES Antarctic The Antarctic |