Grounding line stability in a regime of low driving and basal stresses
Abstract The dynamics of a marine ice sheet's grounding lines determine the rate of ice discharge from the grounded part of ice sheet into surrounding oceans. In many locations in West Antarctica ice flows into ice shelves through ice streams experiencing low driving stress. However, existing s...
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Cambridge University Press (CUP)
2019
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Online Access: | http://dx.doi.org/10.1017/jog.2019.53 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143019000534 |
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crcambridgeupr:10.1017/jog.2019.53 2024-09-15T17:44:06+00:00 Grounding line stability in a regime of low driving and basal stresses Sergienko, O. V. Wingham, D. J. 2019 http://dx.doi.org/10.1017/jog.2019.53 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143019000534 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by/4.0/ Journal of Glaciology volume 65, issue 253, page 833-849 ISSN 0022-1430 1727-5652 journal-article 2019 crcambridgeupr https://doi.org/10.1017/jog.2019.53 2024-09-04T04:04:50Z Abstract The dynamics of a marine ice sheet's grounding lines determine the rate of ice discharge from the grounded part of ice sheet into surrounding oceans. In many locations in West Antarctica ice flows into ice shelves through ice streams experiencing low driving stress. However, existing simple theories of marine ice sheets are developed under the assumption of high basal and driving stress. Here we analyze the grounding line behavior of marine ice streams experiencing low basal shear and driving stress. We find that in this regime, the ice flux at the grounding line is a complex function of the geometry of the ice-stream bed, net accumulation rate and gradient of the net accumulation rate. Our analysis shows that the stability of distinct steady states is determined by the same parameters, suggesting a more complex (in)stability criterion than what is commonly referred to within the context of the ‘marine ice-sheet instability hypothesis’. We also determine characteristic timescales ( e -folding time) of ice-sheet configurations perturbed from their steady states. These timescales can be used to determine whether particular configurations can be considered in isolation from other components of the climate system or whether their effects and feedbacks between the ice sheet and the rest of the climate system have to be taken into account. Article in Journal/Newspaper Antarc* Antarctica Ice Sheet Ice Shelves Journal of Glaciology West Antarctica Cambridge University Press Journal of Glaciology 65 253 833 849 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
Abstract The dynamics of a marine ice sheet's grounding lines determine the rate of ice discharge from the grounded part of ice sheet into surrounding oceans. In many locations in West Antarctica ice flows into ice shelves through ice streams experiencing low driving stress. However, existing simple theories of marine ice sheets are developed under the assumption of high basal and driving stress. Here we analyze the grounding line behavior of marine ice streams experiencing low basal shear and driving stress. We find that in this regime, the ice flux at the grounding line is a complex function of the geometry of the ice-stream bed, net accumulation rate and gradient of the net accumulation rate. Our analysis shows that the stability of distinct steady states is determined by the same parameters, suggesting a more complex (in)stability criterion than what is commonly referred to within the context of the ‘marine ice-sheet instability hypothesis’. We also determine characteristic timescales ( e -folding time) of ice-sheet configurations perturbed from their steady states. These timescales can be used to determine whether particular configurations can be considered in isolation from other components of the climate system or whether their effects and feedbacks between the ice sheet and the rest of the climate system have to be taken into account. |
format |
Article in Journal/Newspaper |
author |
Sergienko, O. V. Wingham, D. J. |
spellingShingle |
Sergienko, O. V. Wingham, D. J. Grounding line stability in a regime of low driving and basal stresses |
author_facet |
Sergienko, O. V. Wingham, D. J. |
author_sort |
Sergienko, O. V. |
title |
Grounding line stability in a regime of low driving and basal stresses |
title_short |
Grounding line stability in a regime of low driving and basal stresses |
title_full |
Grounding line stability in a regime of low driving and basal stresses |
title_fullStr |
Grounding line stability in a regime of low driving and basal stresses |
title_full_unstemmed |
Grounding line stability in a regime of low driving and basal stresses |
title_sort |
grounding line stability in a regime of low driving and basal stresses |
publisher |
Cambridge University Press (CUP) |
publishDate |
2019 |
url |
http://dx.doi.org/10.1017/jog.2019.53 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143019000534 |
genre |
Antarc* Antarctica Ice Sheet Ice Shelves Journal of Glaciology West Antarctica |
genre_facet |
Antarc* Antarctica Ice Sheet Ice Shelves Journal of Glaciology West Antarctica |
op_source |
Journal of Glaciology volume 65, issue 253, page 833-849 ISSN 0022-1430 1727-5652 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1017/jog.2019.53 |
container_title |
Journal of Glaciology |
container_volume |
65 |
container_issue |
253 |
container_start_page |
833 |
op_container_end_page |
849 |
_version_ |
1810491447958306816 |