Performance and applicability of a 2.5-D ice-flow model in the vicinity of a dome
International audience Three-dimensional ice flow modelling requires a large number of computing resources and observation data, such that 2-D simulations are often preferable. However, when there is significant lateral divergence, this must be accounted for (2.5-D models), and a flow tube is consid...
Published in: | Geoscientific Model Development |
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Main Authors: | , , , , , |
Other Authors: | , , , , , |
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-01388819 https://insu.hal.science/insu-01388819/document https://insu.hal.science/insu-01388819/file/GEOSCIENTIFIC%20MODEL%20DEVELOPMENT%20-%20Performance%20and%20applicability%20of%20a%202.5-D%20ice-flow%20model%20in%20the%20vicinity%20of%20a%20dome.pdf https://doi.org/10.5194/gmd-9-2301-2016 |
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Université Savoie Mont Blanc: HAL |
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ftunivsavoie |
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English |
topic |
[SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology |
spellingShingle |
[SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology Passalacqua, Olivier Gagliardini, Olivier Parrenin, Frédéric Todd, Joe Gillet-Chaulet, Fabien Ritz, Catherine Performance and applicability of a 2.5-D ice-flow model in the vicinity of a dome |
topic_facet |
[SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology |
description |
International audience Three-dimensional ice flow modelling requires a large number of computing resources and observation data, such that 2-D simulations are often preferable. However, when there is significant lateral divergence, this must be accounted for (2.5-D models), and a flow tube is considered (volume between two horizontal flowlines). In the absence of velocity observations, this flow tube can be derived assuming that the flowlines follow the steepest slope of the surface, under a few flow assumptions. This method typically consists of scanning a digital elevation model (DEM) with a moving window and computing the curvature at the centre of this window. The ability of the 2.5-D models to account properly for a 3-D state of strain and stress has not clearly been established, nor their sensitivity to the size of the scanning window and to the geometry of the ice surface, for example in the cases of sharp ridges. Here, we study the applicability of a 2.5-D ice flow model around a dome, typical of the East Antarctic plateau conditions. A twin experiment is carried out, comparing 3-D and 2.5-D computed velocities, on three dome geometries, for several scanning windows and thermal conditions. The chosen scanning window used to evaluate the ice surface curvature should be comparable to the typical radius of this curvature. For isothermal ice, the error made by the 2.5-D model is in the range 0–10 % for weakly diverging flows, but is 2 or 3 times higher for highly diverging flows and could lead to a non-physical ice surface at the dome. For non-isothermal ice, assuming a linear temperature profile, the presence of a sharp ridge makes the 2.5-D velocity field unre-alistic. In such cases, the basal ice is warmer and more easily laterally strained than the upper one, the walls of the flow tube are not vertical, and the assumptions of the 2.5-D model are no longer valid. |
author2 |
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 ) Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ) Scott Polar Research Institute University of Cambridge UK (CAM) |
format |
Article in Journal/Newspaper |
author |
Passalacqua, Olivier Gagliardini, Olivier Parrenin, Frédéric Todd, Joe Gillet-Chaulet, Fabien Ritz, Catherine |
author_facet |
Passalacqua, Olivier Gagliardini, Olivier Parrenin, Frédéric Todd, Joe Gillet-Chaulet, Fabien Ritz, Catherine |
author_sort |
Passalacqua, Olivier |
title |
Performance and applicability of a 2.5-D ice-flow model in the vicinity of a dome |
title_short |
Performance and applicability of a 2.5-D ice-flow model in the vicinity of a dome |
title_full |
Performance and applicability of a 2.5-D ice-flow model in the vicinity of a dome |
title_fullStr |
Performance and applicability of a 2.5-D ice-flow model in the vicinity of a dome |
title_full_unstemmed |
Performance and applicability of a 2.5-D ice-flow model in the vicinity of a dome |
title_sort |
performance and applicability of a 2.5-d ice-flow model in the vicinity of a dome |
publisher |
HAL CCSD |
publishDate |
2016 |
url |
https://insu.hal.science/insu-01388819 https://insu.hal.science/insu-01388819/document https://insu.hal.science/insu-01388819/file/GEOSCIENTIFIC%20MODEL%20DEVELOPMENT%20-%20Performance%20and%20applicability%20of%20a%202.5-D%20ice-flow%20model%20in%20the%20vicinity%20of%20a%20dome.pdf https://doi.org/10.5194/gmd-9-2301-2016 |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
ISSN: 1991-962X Geoscientific Model Development Discussions https://insu.hal.science/insu-01388819 Geoscientific Model Development Discussions, 2016, 9 (7), pp.2301-2313. ⟨10.5194/gmd-9-2301-2016⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/gmd-9-2301-2016 insu-01388819 https://insu.hal.science/insu-01388819 https://insu.hal.science/insu-01388819/document https://insu.hal.science/insu-01388819/file/GEOSCIENTIFIC%20MODEL%20DEVELOPMENT%20-%20Performance%20and%20applicability%20of%20a%202.5-D%20ice-flow%20model%20in%20the%20vicinity%20of%20a%20dome.pdf doi:10.5194/gmd-9-2301-2016 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.5194/gmd-9-2301-2016 |
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Geoscientific Model Development |
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7 |
container_start_page |
2301 |
op_container_end_page |
2313 |
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ftunivsavoie:oai:HAL:insu-01388819v1 2024-04-28T07:58:11+00:00 Performance and applicability of a 2.5-D ice-flow model in the vicinity of a dome Passalacqua, Olivier Gagliardini, Olivier Parrenin, Frédéric Todd, Joe Gillet-Chaulet, Fabien Ritz, Catherine 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 ) Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ) Scott Polar Research Institute University of Cambridge UK (CAM) 2016 https://insu.hal.science/insu-01388819 https://insu.hal.science/insu-01388819/document https://insu.hal.science/insu-01388819/file/GEOSCIENTIFIC%20MODEL%20DEVELOPMENT%20-%20Performance%20and%20applicability%20of%20a%202.5-D%20ice-flow%20model%20in%20the%20vicinity%20of%20a%20dome.pdf https://doi.org/10.5194/gmd-9-2301-2016 en eng HAL CCSD Copernicus Publ info:eu-repo/semantics/altIdentifier/doi/10.5194/gmd-9-2301-2016 insu-01388819 https://insu.hal.science/insu-01388819 https://insu.hal.science/insu-01388819/document https://insu.hal.science/insu-01388819/file/GEOSCIENTIFIC%20MODEL%20DEVELOPMENT%20-%20Performance%20and%20applicability%20of%20a%202.5-D%20ice-flow%20model%20in%20the%20vicinity%20of%20a%20dome.pdf doi:10.5194/gmd-9-2301-2016 info:eu-repo/semantics/OpenAccess ISSN: 1991-962X Geoscientific Model Development Discussions https://insu.hal.science/insu-01388819 Geoscientific Model Development Discussions, 2016, 9 (7), pp.2301-2313. ⟨10.5194/gmd-9-2301-2016⟩ [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology info:eu-repo/semantics/article Journal articles 2016 ftunivsavoie https://doi.org/10.5194/gmd-9-2301-2016 2024-04-11T00:59:07Z International audience Three-dimensional ice flow modelling requires a large number of computing resources and observation data, such that 2-D simulations are often preferable. However, when there is significant lateral divergence, this must be accounted for (2.5-D models), and a flow tube is considered (volume between two horizontal flowlines). In the absence of velocity observations, this flow tube can be derived assuming that the flowlines follow the steepest slope of the surface, under a few flow assumptions. This method typically consists of scanning a digital elevation model (DEM) with a moving window and computing the curvature at the centre of this window. The ability of the 2.5-D models to account properly for a 3-D state of strain and stress has not clearly been established, nor their sensitivity to the size of the scanning window and to the geometry of the ice surface, for example in the cases of sharp ridges. Here, we study the applicability of a 2.5-D ice flow model around a dome, typical of the East Antarctic plateau conditions. A twin experiment is carried out, comparing 3-D and 2.5-D computed velocities, on three dome geometries, for several scanning windows and thermal conditions. The chosen scanning window used to evaluate the ice surface curvature should be comparable to the typical radius of this curvature. For isothermal ice, the error made by the 2.5-D model is in the range 0–10 % for weakly diverging flows, but is 2 or 3 times higher for highly diverging flows and could lead to a non-physical ice surface at the dome. For non-isothermal ice, assuming a linear temperature profile, the presence of a sharp ridge makes the 2.5-D velocity field unre-alistic. In such cases, the basal ice is warmer and more easily laterally strained than the upper one, the walls of the flow tube are not vertical, and the assumptions of the 2.5-D model are no longer valid. Article in Journal/Newspaper Antarc* Antarctic Université Savoie Mont Blanc: HAL Geoscientific Model Development 9 7 2301 2313 |