Sensitivity of basal conditions in an inverse model: Vestfonna ice cap, Nordaustlandet/Svalbard
The dynamics of Vestfonna ice cap (Svalbard) are dominated by fast-flowing outlet glaciers. Its mass balance is poorly known and affected dynamically by these fast-flowing outlet glaciers. Hence, it is a challenging target for ice flow modeling. Precise knowledge of the basal conditions and implemen...
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Copernicus Publications
2012
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Online Access: | https://doi.org/10.5194/tc-6-771-2012 http://www.the-cryosphere.net/6/771/2012/tc-6-771-2012.pdf https://doaj.org/article/2b1db1ec94174eed8fde45bf0333f4c8 |
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fttriple:oai:gotriple.eu:oai:doaj.org/article:2b1db1ec94174eed8fde45bf0333f4c8 2023-05-15T16:22:15+02:00 Sensitivity of basal conditions in an inverse model: Vestfonna ice cap, Nordaustlandet/Svalbard M. Schäfer T. Zwinger P. Christoffersen F. Gillet-Chaulet K. Laakso R. Pettersson V. A. Pohjola T. Strozzi J. C. Moore 2012-07-01 https://doi.org/10.5194/tc-6-771-2012 http://www.the-cryosphere.net/6/771/2012/tc-6-771-2012.pdf https://doaj.org/article/2b1db1ec94174eed8fde45bf0333f4c8 en eng Copernicus Publications doi:10.5194/tc-6-771-2012 1994-0416 1994-0424 http://www.the-cryosphere.net/6/771/2012/tc-6-771-2012.pdf https://doaj.org/article/2b1db1ec94174eed8fde45bf0333f4c8 undefined The Cryosphere, Vol 6, Iss 4, Pp 771-783 (2012) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2012 fttriple https://doi.org/10.5194/tc-6-771-2012 2023-01-22T17:51:46Z The dynamics of Vestfonna ice cap (Svalbard) are dominated by fast-flowing outlet glaciers. Its mass balance is poorly known and affected dynamically by these fast-flowing outlet glaciers. Hence, it is a challenging target for ice flow modeling. Precise knowledge of the basal conditions and implementation of a good sliding law are crucial for the modeling of this ice cap. Here we use the full-Stokes finite element code Elmer/Ice to model the 3-D flow over the whole ice cap. We use a Robin inverse method to infer the basal friction from the surface velocities observed in 1995. Our results illustrate the importance of the basal friction parameter in reproducing observed velocity fields. We also show the importance of having variable basal friction as given by the inverse method to reproduce the velocity fields of each outlet glacier – a simple parametrization of basal friction cannot give realistic velocities in a forward model. We study the robustness and sensitivity of this method with respect to different parameters (mesh characteristics, ice temperature, errors in topographic and velocity data). The uncertainty in the observational parameters and input data proved to be sufficiently small as not to adversely affect the fidelity of the model. Article in Journal/Newspaper glacier Ice cap Nordaustlandet Svalbard The Cryosphere Vestfonna Unknown Nordaustlandet ENVELOPE(22.400,22.400,79.800,79.800) Svalbard Vestfonna ENVELOPE(20.761,20.761,79.941,79.941) The Cryosphere 6 4 771 783 |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
fttriple |
language |
English |
topic |
geo envir |
spellingShingle |
geo envir M. Schäfer T. Zwinger P. Christoffersen F. Gillet-Chaulet K. Laakso R. Pettersson V. A. Pohjola T. Strozzi J. C. Moore Sensitivity of basal conditions in an inverse model: Vestfonna ice cap, Nordaustlandet/Svalbard |
topic_facet |
geo envir |
description |
The dynamics of Vestfonna ice cap (Svalbard) are dominated by fast-flowing outlet glaciers. Its mass balance is poorly known and affected dynamically by these fast-flowing outlet glaciers. Hence, it is a challenging target for ice flow modeling. Precise knowledge of the basal conditions and implementation of a good sliding law are crucial for the modeling of this ice cap. Here we use the full-Stokes finite element code Elmer/Ice to model the 3-D flow over the whole ice cap. We use a Robin inverse method to infer the basal friction from the surface velocities observed in 1995. Our results illustrate the importance of the basal friction parameter in reproducing observed velocity fields. We also show the importance of having variable basal friction as given by the inverse method to reproduce the velocity fields of each outlet glacier – a simple parametrization of basal friction cannot give realistic velocities in a forward model. We study the robustness and sensitivity of this method with respect to different parameters (mesh characteristics, ice temperature, errors in topographic and velocity data). The uncertainty in the observational parameters and input data proved to be sufficiently small as not to adversely affect the fidelity of the model. |
format |
Article in Journal/Newspaper |
author |
M. Schäfer T. Zwinger P. Christoffersen F. Gillet-Chaulet K. Laakso R. Pettersson V. A. Pohjola T. Strozzi J. C. Moore |
author_facet |
M. Schäfer T. Zwinger P. Christoffersen F. Gillet-Chaulet K. Laakso R. Pettersson V. A. Pohjola T. Strozzi J. C. Moore |
author_sort |
M. Schäfer |
title |
Sensitivity of basal conditions in an inverse model: Vestfonna ice cap, Nordaustlandet/Svalbard |
title_short |
Sensitivity of basal conditions in an inverse model: Vestfonna ice cap, Nordaustlandet/Svalbard |
title_full |
Sensitivity of basal conditions in an inverse model: Vestfonna ice cap, Nordaustlandet/Svalbard |
title_fullStr |
Sensitivity of basal conditions in an inverse model: Vestfonna ice cap, Nordaustlandet/Svalbard |
title_full_unstemmed |
Sensitivity of basal conditions in an inverse model: Vestfonna ice cap, Nordaustlandet/Svalbard |
title_sort |
sensitivity of basal conditions in an inverse model: vestfonna ice cap, nordaustlandet/svalbard |
publisher |
Copernicus Publications |
publishDate |
2012 |
url |
https://doi.org/10.5194/tc-6-771-2012 http://www.the-cryosphere.net/6/771/2012/tc-6-771-2012.pdf https://doaj.org/article/2b1db1ec94174eed8fde45bf0333f4c8 |
long_lat |
ENVELOPE(22.400,22.400,79.800,79.800) ENVELOPE(20.761,20.761,79.941,79.941) |
geographic |
Nordaustlandet Svalbard Vestfonna |
geographic_facet |
Nordaustlandet Svalbard Vestfonna |
genre |
glacier Ice cap Nordaustlandet Svalbard The Cryosphere Vestfonna |
genre_facet |
glacier Ice cap Nordaustlandet Svalbard The Cryosphere Vestfonna |
op_source |
The Cryosphere, Vol 6, Iss 4, Pp 771-783 (2012) |
op_relation |
doi:10.5194/tc-6-771-2012 1994-0416 1994-0424 http://www.the-cryosphere.net/6/771/2012/tc-6-771-2012.pdf https://doaj.org/article/2b1db1ec94174eed8fde45bf0333f4c8 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-6-771-2012 |
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The Cryosphere |
container_volume |
6 |
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4 |
container_start_page |
771 |
op_container_end_page |
783 |
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1766010217178333184 |