Diverse behaviors of marine ice sheets in response to temporal variability of the atmospheric and basal conditions
Abstract The observed retreat of the grounding line of the present-day ice sheets and the simulated grounding-line retreat of ice sheets under changing climate conditions are often interpreted as indications of marine ice-sheet instability (MISI), driven by a positive feedback between the ice discha...
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Cambridge University Press (CUP)
2024
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Online Access: | http://dx.doi.org/10.1017/jog.2024.43 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143024000431 |
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crcambridgeupr:10.1017/jog.2024.43 2024-09-30T14:36:36+00:00 Diverse behaviors of marine ice sheets in response to temporal variability of the atmospheric and basal conditions Sergienko, Olga Wingham, Duncan John Climate Program Office 2024 http://dx.doi.org/10.1017/jog.2024.43 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143024000431 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by/4.0/ Journal of Glaciology page 1-12 ISSN 0022-1430 1727-5652 journal-article 2024 crcambridgeupr https://doi.org/10.1017/jog.2024.43 2024-09-04T04:04:14Z Abstract The observed retreat of the grounding line of the present-day ice sheets and the simulated grounding-line retreat of ice sheets under changing climate conditions are often interpreted as indications of marine ice-sheet instability (MISI), driven by a positive feedback between the ice discharge and conditions at the grounding line. However, the arguments that support this feedback are valid only for steady-state conditions. Here, we assess how unconfined marine ice sheets may behave if atmospheric conditions and basal conditions evolve with time. We find that the behavior of grounding lines can exhibit a range from unstoppable advance and retreat to irregular oscillation irrespective of the stability of the corresponding steady-state configurations obtained with time-invariant conditions. Our results show that numerical simulations with a parameterization of the ice flux through the grounding line used in large-scale ice-sheet models produce markedly different results from simulations without the parameterization. Our analysis demonstrates that the grounding-line migration can be driven by the temporal variability in the atmospheric and basal conditions and not by MISI, which assumes unchanging conditions. Instead, the grounding-line advance or retreat is determined by interactions between ice flow, basal processes and environmental conditions throughout the length of a marine ice sheet in addition to the circumstances at its grounding line. Article in Journal/Newspaper Ice Sheet Journal of Glaciology Cambridge University Press Misi ENVELOPE(26.683,26.683,66.617,66.617) Journal of Glaciology 1 30 |
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Open Polar |
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Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
description |
Abstract The observed retreat of the grounding line of the present-day ice sheets and the simulated grounding-line retreat of ice sheets under changing climate conditions are often interpreted as indications of marine ice-sheet instability (MISI), driven by a positive feedback between the ice discharge and conditions at the grounding line. However, the arguments that support this feedback are valid only for steady-state conditions. Here, we assess how unconfined marine ice sheets may behave if atmospheric conditions and basal conditions evolve with time. We find that the behavior of grounding lines can exhibit a range from unstoppable advance and retreat to irregular oscillation irrespective of the stability of the corresponding steady-state configurations obtained with time-invariant conditions. Our results show that numerical simulations with a parameterization of the ice flux through the grounding line used in large-scale ice-sheet models produce markedly different results from simulations without the parameterization. Our analysis demonstrates that the grounding-line migration can be driven by the temporal variability in the atmospheric and basal conditions and not by MISI, which assumes unchanging conditions. Instead, the grounding-line advance or retreat is determined by interactions between ice flow, basal processes and environmental conditions throughout the length of a marine ice sheet in addition to the circumstances at its grounding line. |
author2 |
Climate Program Office |
format |
Article in Journal/Newspaper |
author |
Sergienko, Olga Wingham, Duncan John |
spellingShingle |
Sergienko, Olga Wingham, Duncan John Diverse behaviors of marine ice sheets in response to temporal variability of the atmospheric and basal conditions |
author_facet |
Sergienko, Olga Wingham, Duncan John |
author_sort |
Sergienko, Olga |
title |
Diverse behaviors of marine ice sheets in response to temporal variability of the atmospheric and basal conditions |
title_short |
Diverse behaviors of marine ice sheets in response to temporal variability of the atmospheric and basal conditions |
title_full |
Diverse behaviors of marine ice sheets in response to temporal variability of the atmospheric and basal conditions |
title_fullStr |
Diverse behaviors of marine ice sheets in response to temporal variability of the atmospheric and basal conditions |
title_full_unstemmed |
Diverse behaviors of marine ice sheets in response to temporal variability of the atmospheric and basal conditions |
title_sort |
diverse behaviors of marine ice sheets in response to temporal variability of the atmospheric and basal conditions |
publisher |
Cambridge University Press (CUP) |
publishDate |
2024 |
url |
http://dx.doi.org/10.1017/jog.2024.43 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143024000431 |
long_lat |
ENVELOPE(26.683,26.683,66.617,66.617) |
geographic |
Misi |
geographic_facet |
Misi |
genre |
Ice Sheet Journal of Glaciology |
genre_facet |
Ice Sheet Journal of Glaciology |
op_source |
Journal of Glaciology page 1-12 ISSN 0022-1430 1727-5652 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1017/jog.2024.43 |
container_title |
Journal of Glaciology |
container_start_page |
1 |
op_container_end_page |
30 |
_version_ |
1811639637707325440 |