Snowfall versus sub-shelf melt: response of an idealized 3D ice-sheet-shelf system to mass redistribution
Surface accumulation and sub-ice-shelf melting are key drivers for the flow dynamics of the Antarctic Ice Sheet and are most likely to change under future warming which leads to 1) higher snowfall and 2) stronger melting below ice shelves. Here we carry out conceptual simulations in which an equilib...
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ftpubman:oai:pure.mpg.de:item_3524136 2023-09-05T13:15:16+02:00 Snowfall versus sub-shelf melt: response of an idealized 3D ice-sheet-shelf system to mass redistribution Feldmann, J. Reese, R. Winkelmann, R. Levermann, A. 2018-07-18 application/pdf http://hdl.handle.net/21.11116/0000-000D-8C83-1 http://hdl.handle.net/21.11116/0000-000D-8C85-F eng eng info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-2018-109 http://hdl.handle.net/21.11116/0000-000D-8C83-1 http://hdl.handle.net/21.11116/0000-000D-8C85-F info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/ The Cryosphere Discussions info:eu-repo/semantics/preprint 2018 ftpubman https://doi.org/10.5194/tc-2018-109 2023-08-13T23:44:08Z Surface accumulation and sub-ice-shelf melting are key drivers for the flow dynamics of the Antarctic Ice Sheet and are most likely to change under future warming which leads to 1) higher snowfall and 2) stronger melting below ice shelves. Here we carry out conceptual simulations in which an equilibrium ice-sheet-shelf system is perturbed such that the increased sub-shelf melting is compensated by enhanced snowfall. Although the net surface mass balance of the whole system remains unchanged, the redistribution of mass leads to a dynamic response of the ice sheet due to changes in ice thickness, surface slope, ice-shelf backstress and ice discharge. In particular, we show that such forcing can lead to the counter-intuitive situation of a retreating ice sheet which gains mass, thus having a negative sea-level contribution but smaller ice-sheet extent. The ice-sheet evolution and the corresponding steady states are investigated varying relevant parameters that affect ice properties and bed geometry as well as for different magnitudes of mass redistribution. Furthermore, the ice-sheet response is analyzed with respect to the pattern of applied melting, i.e., the area over which melting is distributed and the location where it is applied. We find throughout the ensemble of simulations that after two decades, melting at the lateral ice-shelf margins induces more ice-shelf thinning, resulting in stronger grounding line retreat and transient ice discharge compared to melting adjacent to the central grounding-line section. Analyzing changes in ice-shelf backstress with respect to changes in the ice-shelf length and mean thickness, respectively, we show that a thickness change has up to four times more influence on the backstress of the ice shelf than a length change. Report Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves The Cryosphere The Cryosphere Discussions Max Planck Society: MPG.PuRe Antarctic The Antarctic |
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Max Planck Society: MPG.PuRe |
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ftpubman |
language |
English |
description |
Surface accumulation and sub-ice-shelf melting are key drivers for the flow dynamics of the Antarctic Ice Sheet and are most likely to change under future warming which leads to 1) higher snowfall and 2) stronger melting below ice shelves. Here we carry out conceptual simulations in which an equilibrium ice-sheet-shelf system is perturbed such that the increased sub-shelf melting is compensated by enhanced snowfall. Although the net surface mass balance of the whole system remains unchanged, the redistribution of mass leads to a dynamic response of the ice sheet due to changes in ice thickness, surface slope, ice-shelf backstress and ice discharge. In particular, we show that such forcing can lead to the counter-intuitive situation of a retreating ice sheet which gains mass, thus having a negative sea-level contribution but smaller ice-sheet extent. The ice-sheet evolution and the corresponding steady states are investigated varying relevant parameters that affect ice properties and bed geometry as well as for different magnitudes of mass redistribution. Furthermore, the ice-sheet response is analyzed with respect to the pattern of applied melting, i.e., the area over which melting is distributed and the location where it is applied. We find throughout the ensemble of simulations that after two decades, melting at the lateral ice-shelf margins induces more ice-shelf thinning, resulting in stronger grounding line retreat and transient ice discharge compared to melting adjacent to the central grounding-line section. Analyzing changes in ice-shelf backstress with respect to changes in the ice-shelf length and mean thickness, respectively, we show that a thickness change has up to four times more influence on the backstress of the ice shelf than a length change. |
format |
Report |
author |
Feldmann, J. Reese, R. Winkelmann, R. Levermann, A. |
spellingShingle |
Feldmann, J. Reese, R. Winkelmann, R. Levermann, A. Snowfall versus sub-shelf melt: response of an idealized 3D ice-sheet-shelf system to mass redistribution |
author_facet |
Feldmann, J. Reese, R. Winkelmann, R. Levermann, A. |
author_sort |
Feldmann, J. |
title |
Snowfall versus sub-shelf melt: response of an idealized 3D ice-sheet-shelf system to mass redistribution |
title_short |
Snowfall versus sub-shelf melt: response of an idealized 3D ice-sheet-shelf system to mass redistribution |
title_full |
Snowfall versus sub-shelf melt: response of an idealized 3D ice-sheet-shelf system to mass redistribution |
title_fullStr |
Snowfall versus sub-shelf melt: response of an idealized 3D ice-sheet-shelf system to mass redistribution |
title_full_unstemmed |
Snowfall versus sub-shelf melt: response of an idealized 3D ice-sheet-shelf system to mass redistribution |
title_sort |
snowfall versus sub-shelf melt: response of an idealized 3d ice-sheet-shelf system to mass redistribution |
publishDate |
2018 |
url |
http://hdl.handle.net/21.11116/0000-000D-8C83-1 http://hdl.handle.net/21.11116/0000-000D-8C85-F |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves The Cryosphere The Cryosphere Discussions |
genre_facet |
Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves The Cryosphere The Cryosphere Discussions |
op_source |
The Cryosphere Discussions |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-2018-109 http://hdl.handle.net/21.11116/0000-000D-8C83-1 http://hdl.handle.net/21.11116/0000-000D-8C85-F |
op_rights |
info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.5194/tc-2018-109 |
_version_ |
1776197084972580864 |