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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ftfuberlin:oai:refubium.fu-berlin.de:fub188/21007 2023-05-15T13:50:49+02:00 Comparison of hybrid schemes for the combination of shallow approximations in numerical simulations of the Antarctic Ice Sheet Bernales, Jorge Rogozhina, Irina Greve, Ralf Thomas, Maik 2017 19 S. application/pdf https://refubium.fu-berlin.de/handle/fub188/21007 https://doi.org/10.17169/refubium-24304 https://doi.org/10.5194/tc-11-247-2017 eng eng https://refubium.fu-berlin.de/handle/fub188/21007 http://dx.doi.org/10.17169/refubium-24304 doi:10.5194/tc-11-247-2017 http://creativecommons.org/licenses/by/3.0/ CC-BY ddc:550 doc-type:article 2017 ftfuberlin https://doi.org/10.17169/refubium-24304 https://doi.org/10.5194/tc-11-247-2017 2022-05-15T20:45:25Z 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 Freie Universität Berlin: Refubium (FU Berlin) Antarctic The Antarctic The Cryosphere 11 1 247 265 |
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Open Polar |
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Freie Universität Berlin: Refubium (FU Berlin) |
op_collection_id |
ftfuberlin |
language |
English |
topic |
ddc:550 |
spellingShingle |
ddc:550 Bernales, Jorge Rogozhina, Irina Greve, Ralf Thomas, Maik Comparison of hybrid schemes for the combination of shallow approximations in numerical simulations of the Antarctic Ice Sheet |
topic_facet |
ddc:550 |
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 |
Bernales, Jorge Rogozhina, Irina Greve, Ralf Thomas, Maik |
author_facet |
Bernales, Jorge Rogozhina, Irina Greve, Ralf Thomas, Maik |
author_sort |
Bernales, Jorge |
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://refubium.fu-berlin.de/handle/fub188/21007 https://doi.org/10.17169/refubium-24304 https://doi.org/10.5194/tc-11-247-2017 |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Ice Sheet |
genre_facet |
Antarc* Antarctic Ice Sheet |
op_relation |
https://refubium.fu-berlin.de/handle/fub188/21007 http://dx.doi.org/10.17169/refubium-24304 doi:10.5194/tc-11-247-2017 |
op_rights |
http://creativecommons.org/licenses/by/3.0/ |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.17169/refubium-24304 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_ |
1766254104061935616 |