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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Format: | Article in Journal/Newspaper |
Language: | English |
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Uppsala universitet, Luft-, vatten- och landskapslära
2012
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Online Access: | http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-186071 https://doi.org/10.5194/tc-6-771-2012 |
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ftuppsalauniv:oai:DiVA.org:uu-186071 2023-05-15T15:10:07+02:00 Sensitivity of basal conditions in an inverse model : Vestfonna ice cap, Nordaustlandet/Svalbard Schäfer, M. Zwinger, T. Christoffersen, P. Gillet-Chaulet, F. Laakso, K. Pettersson, Rickard Pohjola, Veijo A. Strozzi, T. Moore, John C. 2012 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-186071 https://doi.org/10.5194/tc-6-771-2012 eng eng Uppsala universitet, Luft-, vatten- och landskapslära The Cryosphere, 1994-0416, 2012, 6:4, s. 771-783 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-186071 doi:10.5194/tc-6-771-2012 ISI:000308246500005 info:eu-repo/semantics/openAccess cryosphere finite element method forward modeling ice cap ice flow inverse analysis mass balance numerical model parameterization sensitivity analysis sliding three-dimensional flow uncertainty analysis velocity structure Arctic Nordaustlandet Svalbard Svalbard and Jan Mayen Vestfonna Earth and Related Environmental Sciences Geovetenskap och miljövetenskap Article in journal info:eu-repo/semantics/article text 2012 ftuppsalauniv https://doi.org/10.5194/tc-6-771-2012 2023-02-23T21:52:08Z 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 Arctic glacier Ice cap Jan Mayen Nordaustlandet Svalbard The Cryosphere Vestfonna Uppsala University: Publications (DiVA) Arctic Jan Mayen Nordaustlandet ENVELOPE(22.400,22.400,79.800,79.800) Svalbard Svalbard ENVELOPE(20.000,20.000,78.000,78.000) Vestfonna ENVELOPE(20.761,20.761,79.941,79.941) The Cryosphere 6 4 771 783 |
institution |
Open Polar |
collection |
Uppsala University: Publications (DiVA) |
op_collection_id |
ftuppsalauniv |
language |
English |
topic |
cryosphere finite element method forward modeling ice cap ice flow inverse analysis mass balance numerical model parameterization sensitivity analysis sliding three-dimensional flow uncertainty analysis velocity structure Arctic Nordaustlandet Svalbard Svalbard and Jan Mayen Vestfonna Earth and Related Environmental Sciences Geovetenskap och miljövetenskap |
spellingShingle |
cryosphere finite element method forward modeling ice cap ice flow inverse analysis mass balance numerical model parameterization sensitivity analysis sliding three-dimensional flow uncertainty analysis velocity structure Arctic Nordaustlandet Svalbard Svalbard and Jan Mayen Vestfonna Earth and Related Environmental Sciences Geovetenskap och miljövetenskap Schäfer, M. Zwinger, T. Christoffersen, P. Gillet-Chaulet, F. Laakso, K. Pettersson, Rickard Pohjola, Veijo A. Strozzi, T. Moore, John C. Sensitivity of basal conditions in an inverse model : Vestfonna ice cap, Nordaustlandet/Svalbard |
topic_facet |
cryosphere finite element method forward modeling ice cap ice flow inverse analysis mass balance numerical model parameterization sensitivity analysis sliding three-dimensional flow uncertainty analysis velocity structure Arctic Nordaustlandet Svalbard Svalbard and Jan Mayen Vestfonna Earth and Related Environmental Sciences Geovetenskap och miljövetenskap |
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 |
Schäfer, M. Zwinger, T. Christoffersen, P. Gillet-Chaulet, F. Laakso, K. Pettersson, Rickard Pohjola, Veijo A. Strozzi, T. Moore, John C. |
author_facet |
Schäfer, M. Zwinger, T. Christoffersen, P. Gillet-Chaulet, F. Laakso, K. Pettersson, Rickard Pohjola, Veijo A. Strozzi, T. Moore, John C. |
author_sort |
Schäfer, M. |
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 |
Uppsala universitet, Luft-, vatten- och landskapslära |
publishDate |
2012 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-186071 https://doi.org/10.5194/tc-6-771-2012 |
long_lat |
ENVELOPE(22.400,22.400,79.800,79.800) ENVELOPE(20.000,20.000,78.000,78.000) ENVELOPE(20.761,20.761,79.941,79.941) |
geographic |
Arctic Jan Mayen Nordaustlandet Svalbard Svalbard Vestfonna |
geographic_facet |
Arctic Jan Mayen Nordaustlandet Svalbard Svalbard Vestfonna |
genre |
Arctic glacier Ice cap Jan Mayen Nordaustlandet Svalbard The Cryosphere Vestfonna |
genre_facet |
Arctic glacier Ice cap Jan Mayen Nordaustlandet Svalbard The Cryosphere Vestfonna |
op_relation |
The Cryosphere, 1994-0416, 2012, 6:4, s. 771-783 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-186071 doi:10.5194/tc-6-771-2012 ISI:000308246500005 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/tc-6-771-2012 |
container_title |
The Cryosphere |
container_volume |
6 |
container_issue |
4 |
container_start_page |
771 |
op_container_end_page |
783 |
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1766341172738916352 |