The stability of present-day Antarctic grounding lines – Part A: No indication of marine ice sheet instability in the current geometry
Theoretical and numerical work has firmly established that grounding lines of marine-type ice sheets can enter phases of irreversible advance and retreat driven by the marine ice sheet instability (MISI). Instances of such irreversible retreat have been found in several simulations of the past and f...
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ftcopernicus:oai:publications.copernicus.org:tcd103462 2023-05-15T14:02:18+02:00 The stability of present-day Antarctic grounding lines – Part A: No indication of marine ice sheet instability in the current geometry Urruty, Benoît Hill, Emily A. Reese, Ronja Garbe, Julius Gagliardini, Olivier Durand, Gael Gillet-Chaulet, Fabien Gudmundsson, G. Hilmar Winkelmann, Ricarda Chekki, Mondher Chandler, David Langebroek, Petra M. 2022-06-21 application/pdf https://doi.org/10.5194/tc-2022-104 https://tc.copernicus.org/preprints/tc-2022-104/ eng eng doi:10.5194/tc-2022-104 https://tc.copernicus.org/preprints/tc-2022-104/ eISSN: 1994-0424 Text 2022 ftcopernicus https://doi.org/10.5194/tc-2022-104 2022-06-27T16:22:42Z Theoretical and numerical work has firmly established that grounding lines of marine-type ice sheets can enter phases of irreversible advance and retreat driven by the marine ice sheet instability (MISI). Instances of such irreversible retreat have been found in several simulations of the past and future evolution of the Antarctic Ice Sheet. However, hitherto the stability regime of Antarctic Ice Sheet grounding lines in their current position has not been assessed. Here we conduct a systematic numerical stability analysis of all the grounding lines of the Antarctic Ice Sheet to determine if they are currently undergoing irreversible retreat through MISI. To do this, we initialise three state-of-the-art ice-flow models, Úa, Elmer/Ice, and PISM, to replicate the current geometry of the Antarctic Ice Sheet, and then apply small, but numerically significant, perturbations in ocean-induced ice-shelf melt. We find that the grounding lines around Antarctica migrate slightly away from their initial position while the perturbation is applied, and then revert to the initial state once the perturbation is removed. There is no indication of irreversible or self-sustaining retreat. This suggests that present-day grounding-line retreat is driven by external climate forcing alone. Hence, if the currently observed mass imbalance were to be removed, the grounding-line retreat would likely stop. However, under present-day climate forcing, further grounding-line retreat is expected, and our accompanying paper (Part B, Reese et al., 2022) shows that this could eventually lead to a collapse of some marine regions of West Antarctica. Text Antarc* Antarctic Antarctica Ice Sheet Ice Shelf West Antarctica Copernicus Publications: E-Journals Antarctic Misi ENVELOPE(26.683,26.683,66.617,66.617) The Antarctic West Antarctica |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
Theoretical and numerical work has firmly established that grounding lines of marine-type ice sheets can enter phases of irreversible advance and retreat driven by the marine ice sheet instability (MISI). Instances of such irreversible retreat have been found in several simulations of the past and future evolution of the Antarctic Ice Sheet. However, hitherto the stability regime of Antarctic Ice Sheet grounding lines in their current position has not been assessed. Here we conduct a systematic numerical stability analysis of all the grounding lines of the Antarctic Ice Sheet to determine if they are currently undergoing irreversible retreat through MISI. To do this, we initialise three state-of-the-art ice-flow models, Úa, Elmer/Ice, and PISM, to replicate the current geometry of the Antarctic Ice Sheet, and then apply small, but numerically significant, perturbations in ocean-induced ice-shelf melt. We find that the grounding lines around Antarctica migrate slightly away from their initial position while the perturbation is applied, and then revert to the initial state once the perturbation is removed. There is no indication of irreversible or self-sustaining retreat. This suggests that present-day grounding-line retreat is driven by external climate forcing alone. Hence, if the currently observed mass imbalance were to be removed, the grounding-line retreat would likely stop. However, under present-day climate forcing, further grounding-line retreat is expected, and our accompanying paper (Part B, Reese et al., 2022) shows that this could eventually lead to a collapse of some marine regions of West Antarctica. |
format |
Text |
author |
Urruty, Benoît Hill, Emily A. Reese, Ronja Garbe, Julius Gagliardini, Olivier Durand, Gael Gillet-Chaulet, Fabien Gudmundsson, G. Hilmar Winkelmann, Ricarda Chekki, Mondher Chandler, David Langebroek, Petra M. |
spellingShingle |
Urruty, Benoît Hill, Emily A. Reese, Ronja Garbe, Julius Gagliardini, Olivier Durand, Gael Gillet-Chaulet, Fabien Gudmundsson, G. Hilmar Winkelmann, Ricarda Chekki, Mondher Chandler, David Langebroek, Petra M. The stability of present-day Antarctic grounding lines – Part A: No indication of marine ice sheet instability in the current geometry |
author_facet |
Urruty, Benoît Hill, Emily A. Reese, Ronja Garbe, Julius Gagliardini, Olivier Durand, Gael Gillet-Chaulet, Fabien Gudmundsson, G. Hilmar Winkelmann, Ricarda Chekki, Mondher Chandler, David Langebroek, Petra M. |
author_sort |
Urruty, Benoît |
title |
The stability of present-day Antarctic grounding lines – Part A: No indication of marine ice sheet instability in the current geometry |
title_short |
The stability of present-day Antarctic grounding lines – Part A: No indication of marine ice sheet instability in the current geometry |
title_full |
The stability of present-day Antarctic grounding lines – Part A: No indication of marine ice sheet instability in the current geometry |
title_fullStr |
The stability of present-day Antarctic grounding lines – Part A: No indication of marine ice sheet instability in the current geometry |
title_full_unstemmed |
The stability of present-day Antarctic grounding lines – Part A: No indication of marine ice sheet instability in the current geometry |
title_sort |
stability of present-day antarctic grounding lines – part a: no indication of marine ice sheet instability in the current geometry |
publishDate |
2022 |
url |
https://doi.org/10.5194/tc-2022-104 https://tc.copernicus.org/preprints/tc-2022-104/ |
long_lat |
ENVELOPE(26.683,26.683,66.617,66.617) |
geographic |
Antarctic Misi The Antarctic West Antarctica |
geographic_facet |
Antarctic Misi The Antarctic West Antarctica |
genre |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelf West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelf West Antarctica |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-2022-104 https://tc.copernicus.org/preprints/tc-2022-104/ |
op_doi |
https://doi.org/10.5194/tc-2022-104 |
_version_ |
1766272503999627264 |