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 used in ice-sheet models to simplify the force balance equations within the ice. However, the SIA cannot adequately reproduce the dynamics of the fast flowing ice streams usually found at the margins of ice sheets. To overcome this limitation, recent s...
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fttriple:oai:gotriple.eu:oai:doaj.org/article:bab29ded91304a8da282d02b6ca4bb31 2023-05-15T13:39:35+02:00 Comparison of hybrid schemes for the combination of shallow approximations in numerical simulations of the Antarctic Ice Sheet J. Bernales I. Rogozhina R. Greve M. Thomas 2017-01-01 https://doi.org/10.5194/tc-11-247-2017 http://www.the-cryosphere.net/11/247/2017/tc-11-247-2017.pdf https://doaj.org/article/bab29ded91304a8da282d02b6ca4bb31 en eng Copernicus Publications 1994-0416 1994-0424 doi:10.5194/tc-11-247-2017 http://www.the-cryosphere.net/11/247/2017/tc-11-247-2017.pdf https://doaj.org/article/bab29ded91304a8da282d02b6ca4bb31 undefined The Cryosphere, Vol 11, Iss 1, Pp 247-265 (2017) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2017 fttriple https://doi.org/10.5194/tc-11-247-2017 2023-01-22T18:19:38Z The shallow ice approximation (SIA) is commonly used in ice-sheet models to simplify the force balance equations within the ice. However, the SIA cannot adequately reproduce the dynamics of the fast flowing ice streams usually found at the margins of ice sheets. 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 present-day conditions. 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 iterative technique compensates for the differences between the schemes, producing similar ice-sheet configurations through quantitatively different results of the sliding coefficient calibration. Despite this we observe a robust agreement in the reconstructed patterns of basal sliding parameters. We exchange the calibrated sliding parameter distributions between the schemes to demonstrate that the results of the model calibration cannot be straightforwardly transferred to models based on different approximations of ice dynamics. However, easily adaptable calibration techniques for the potential distribution of basal sliding coefficients can be implemented into ice models to overcome such incompatibility, as shown in this study. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet The Cryosphere Unknown Antarctic The Antarctic The Cryosphere 11 1 247 265 |
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geo envir J. Bernales I. Rogozhina R. Greve M. Thomas Comparison of hybrid schemes for the combination of shallow approximations in numerical simulations of the Antarctic Ice Sheet |
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geo envir |
description |
The shallow ice approximation (SIA) is commonly used in ice-sheet models to simplify the force balance equations within the ice. However, the SIA cannot adequately reproduce the dynamics of the fast flowing ice streams usually found at the margins of ice sheets. 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 present-day conditions. 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 iterative technique compensates for the differences between the schemes, producing similar ice-sheet configurations through quantitatively different results of the sliding coefficient calibration. Despite this we observe a robust agreement in the reconstructed patterns of basal sliding parameters. We exchange the calibrated sliding parameter distributions between the schemes to demonstrate that the results of the model calibration cannot be straightforwardly transferred to models based on different approximations of ice dynamics. However, easily adaptable calibration techniques for the potential distribution of basal sliding coefficients can be implemented into ice models to overcome such incompatibility, as shown in this study. |
format |
Article in Journal/Newspaper |
author |
J. Bernales I. Rogozhina R. Greve M. Thomas |
author_facet |
J. Bernales I. Rogozhina R. Greve M. Thomas |
author_sort |
J. Bernales |
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 |
publisher |
Copernicus Publications |
publishDate |
2017 |
url |
https://doi.org/10.5194/tc-11-247-2017 http://www.the-cryosphere.net/11/247/2017/tc-11-247-2017.pdf https://doaj.org/article/bab29ded91304a8da282d02b6ca4bb31 |
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, Vol 11, Iss 1, Pp 247-265 (2017) |
op_relation |
1994-0416 1994-0424 doi:10.5194/tc-11-247-2017 http://www.the-cryosphere.net/11/247/2017/tc-11-247-2017.pdf https://doaj.org/article/bab29ded91304a8da282d02b6ca4bb31 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-11-247-2017 |
container_title |
The Cryosphere |
container_volume |
11 |
container_issue |
1 |
container_start_page |
247 |
op_container_end_page |
265 |
_version_ |
1766120463875964928 |