Comparison of hybrid schemes for the combination of Shallow Approximations in numerical simulations of the Antarctic Ice Sheet
The Shallow Ice Approximation (SIA) is commonly introduced in ice-sheet models to simplify the equations describing ice dynamics. However, the SIA is not applicable in fast flowing regions where basal sliding operates. To overcome this limitation, recent studies have introduced heuristic, hybrid com...
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ftgfzpotsdam:oai:gfzpublic.gfz-potsdam.de:item_1906902 2023-05-15T13:40:19+02:00 Comparison of hybrid schemes for the combination of Shallow Approximations in numerical simulations of the Antarctic Ice Sheet Bernales, J. Rogozhina, I. Greve, R. Thomas, M. 2017 application/pdf https://gfzpublic.gfz-potsdam.de/pubman/item/item_1906902 https://gfzpublic.gfz-potsdam.de/pubman/item/item_1906902_4/component/file_2013888/1906902.pdf unknown info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-2016-117 info:eu-repo/semantics/altIdentifier/urn/http://doi.crossref.org/servlet/query?format=unixref&pid=bib@gfz-potsdam.de&id=10.5194/tc-2016-117 https://gfzpublic.gfz-potsdam.de/pubman/item/item_1906902 https://gfzpublic.gfz-potsdam.de/pubman/item/item_1906902_4/component/file_2013888/1906902.pdf info:eu-repo/semantics/openAccess The Cryosphere info:eu-repo/semantics/article 2017 ftgfzpotsdam https://doi.org/10.5194/tc-2016-117 2022-09-14T05:54:36Z The Shallow Ice Approximation (SIA) is commonly introduced in ice-sheet models to simplify the equations describing ice dynamics. However, the SIA is not applicable in fast flowing regions where basal sliding operates. To overcome this limitation, recent studies have introduced heuristic, hybrid combinations of the SIA and the Shelfy Stream Approximation. Here, we implement four different hybrid schemes into a model of the Antarctic Ice Sheet in order to compare their performance under a realistic scenario. For each scheme, the model is calibrated using an iterative technique to infer the spatial variability in basal sliding parameters. Model results are validated against topographic and velocity data. Our analysis shows that the calibration compensates for the differences between the schemes, producing similar ice sheet configurations through quantitatively different parameter distributions. Despite this, we observe a robust agreement in the reconstructed patterns of hard vs. soft basal conditions. We use averaged and swapped parameter distributions to demonstrate that the results of the model calibration cannot be straightforwardly transferred to models based on different approximations of ice dynamics. However, this requirement for internal consistency can be fulfilled through the implementation of easily adaptable calibration techniques, as shown in this study. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet The Cryosphere GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) Antarctic The Antarctic |
institution |
Open Polar |
collection |
GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) |
op_collection_id |
ftgfzpotsdam |
language |
unknown |
description |
The Shallow Ice Approximation (SIA) is commonly introduced in ice-sheet models to simplify the equations describing ice dynamics. However, the SIA is not applicable in fast flowing regions where basal sliding operates. To overcome this limitation, recent studies have introduced heuristic, hybrid combinations of the SIA and the Shelfy Stream Approximation. Here, we implement four different hybrid schemes into a model of the Antarctic Ice Sheet in order to compare their performance under a realistic scenario. For each scheme, the model is calibrated using an iterative technique to infer the spatial variability in basal sliding parameters. Model results are validated against topographic and velocity data. Our analysis shows that the calibration compensates for the differences between the schemes, producing similar ice sheet configurations through quantitatively different parameter distributions. Despite this, we observe a robust agreement in the reconstructed patterns of hard vs. soft basal conditions. We use averaged and swapped parameter distributions to demonstrate that the results of the model calibration cannot be straightforwardly transferred to models based on different approximations of ice dynamics. However, this requirement for internal consistency can be fulfilled through the implementation of easily adaptable calibration techniques, as shown in this study. |
format |
Article in Journal/Newspaper |
author |
Bernales, J. Rogozhina, I. Greve, R. Thomas, M. |
spellingShingle |
Bernales, J. Rogozhina, I. Greve, R. Thomas, M. Comparison of hybrid schemes for the combination of Shallow Approximations in numerical simulations of the Antarctic Ice Sheet |
author_facet |
Bernales, J. Rogozhina, I. Greve, R. Thomas, M. |
author_sort |
Bernales, J. |
title |
Comparison of hybrid schemes for the combination of Shallow Approximations in numerical simulations of the Antarctic Ice Sheet |
title_short |
Comparison of hybrid schemes for the combination of Shallow Approximations in numerical simulations of the Antarctic Ice Sheet |
title_full |
Comparison of hybrid schemes for the combination of Shallow Approximations in numerical simulations of the Antarctic Ice Sheet |
title_fullStr |
Comparison of hybrid schemes for the combination of Shallow Approximations in numerical simulations of the Antarctic Ice Sheet |
title_full_unstemmed |
Comparison of hybrid schemes for the combination of Shallow Approximations in numerical simulations of the Antarctic Ice Sheet |
title_sort |
comparison of hybrid schemes for the combination of shallow approximations in numerical simulations of the antarctic ice sheet |
publishDate |
2017 |
url |
https://gfzpublic.gfz-potsdam.de/pubman/item/item_1906902 https://gfzpublic.gfz-potsdam.de/pubman/item/item_1906902_4/component/file_2013888/1906902.pdf |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Ice Sheet The Cryosphere |
genre_facet |
Antarc* Antarctic Ice Sheet The Cryosphere |
op_source |
The Cryosphere |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-2016-117 info:eu-repo/semantics/altIdentifier/urn/http://doi.crossref.org/servlet/query?format=unixref&pid=bib@gfz-potsdam.de&id=10.5194/tc-2016-117 https://gfzpublic.gfz-potsdam.de/pubman/item/item_1906902 https://gfzpublic.gfz-potsdam.de/pubman/item/item_1906902_4/component/file_2013888/1906902.pdf |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/tc-2016-117 |
_version_ |
1766132118749970432 |