The stability of present-day Antarctic grounding lines – Part 2: Onset of irreversible retreat of Amundsen Sea glaciers under current climate on centennial timescales cannot be excluded
International audience Abstract. Observations of ocean-driven grounding-line retreat in the Amundsen Sea Embayment in Antarctica raise the question of an imminent collapse of the West Antarctic Ice Sheet. Here we analyse the committed evolution of Antarctic grounding lines under the present-day clim...
Published in: | The Cryosphere |
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Main Authors: | , , , , , , , , , , , |
Other Authors: | , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2023
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Online Access: | https://hal.science/hal-04297038 https://hal.science/hal-04297038/document https://hal.science/hal-04297038/file/tc-17-3761-2023.pdf https://doi.org/10.5194/tc-17-3761-2023 |
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Institut national des sciences de l'Univers: HAL-INSU |
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ftinsu |
language |
English |
topic |
[SDE]Environmental Sciences |
spellingShingle |
[SDE]Environmental Sciences Reese, Ronja Garbe, Julius Hill, Emily Urruty, Benoît Naughten, Kaitlin Gagliardini, Olivier Durand, Gaël Gillet-Chaulet, Fabien Gudmundsson, G. Hilmar Chandler, David Langebroek, Petra Winkelmann, Ricarda The stability of present-day Antarctic grounding lines – Part 2: Onset of irreversible retreat of Amundsen Sea glaciers under current climate on centennial timescales cannot be excluded |
topic_facet |
[SDE]Environmental Sciences |
description |
International audience Abstract. Observations of ocean-driven grounding-line retreat in the Amundsen Sea Embayment in Antarctica raise the question of an imminent collapse of the West Antarctic Ice Sheet. Here we analyse the committed evolution of Antarctic grounding lines under the present-day climate. To this aim, we first calibrate a sub-shelf melt parameterization, which is derived from an ocean box model, with observed and modelled melt sensitivities to ocean temperature changes, making it suitable for present-day simulations and future sea level projections. Using the new calibration, we run an ensemble of historical simulations from 1850 to 2015 with a state-of-the-art ice sheet model to create model instances of possible present-day ice sheet configurations. Then, we extend the simulations for another 10 000 years to investigate their evolution under constant present-day climate forcing and bathymetry. We test for reversibility of grounding-line movement in the case that large-scale retreat occurs. In the Amundsen Sea Embayment we find irreversible retreat of the Thwaites Glacier for all our parameter combinations and irreversible retreat of the Pine Island Glacier for some admissible parameter combinations. Importantly, an irreversible collapse in the Amundsen Sea Embayment sector is initiated at the earliest between 300 and 500 years in our simulations and is not inevitable yet – as also shown in our companion paper (Part 1, Hill et al., 2023). In other words, the region has not tipped yet. With the assumption of constant present-day climate, the collapse evolves on millennial timescales, with a maximum rate of 0.9 mm a−1 sea-level-equivalent ice volume loss. The contribution to sea level by 2300 is limited to 8 cm with a maximum rate of 0.4 mm a−1 sea-level-equivalent ice volume loss. Furthermore, when allowing ice shelves to regrow to their present geometry, we find that large-scale grounding-line retreat into marine basins upstream of the Filchner–Ronne Ice Shelf and the western Siple Coast is ... |
author2 |
University of Northumbria at Newcastle United Kingdom King‘s College London Institut des Géosciences de l’Environnement (IGE) Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ) Université Grenoble Alpes (UGA) Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ) Lawrence Berkeley National Laboratory Berkeley (LBNL) Bjerknes Centre for Climate Research (BCCR) Department of Biological Sciences Bergen (BIO / UiB) University of Bergen (UiB)-University of Bergen (UiB) Potsdam Institute for Climate Impact Research (PIK) University of Potsdam = Universität Potsdam |
format |
Article in Journal/Newspaper |
author |
Reese, Ronja Garbe, Julius Hill, Emily Urruty, Benoît Naughten, Kaitlin Gagliardini, Olivier Durand, Gaël Gillet-Chaulet, Fabien Gudmundsson, G. Hilmar Chandler, David Langebroek, Petra Winkelmann, Ricarda |
author_facet |
Reese, Ronja Garbe, Julius Hill, Emily Urruty, Benoît Naughten, Kaitlin Gagliardini, Olivier Durand, Gaël Gillet-Chaulet, Fabien Gudmundsson, G. Hilmar Chandler, David Langebroek, Petra Winkelmann, Ricarda |
author_sort |
Reese, Ronja |
title |
The stability of present-day Antarctic grounding lines – Part 2: Onset of irreversible retreat of Amundsen Sea glaciers under current climate on centennial timescales cannot be excluded |
title_short |
The stability of present-day Antarctic grounding lines – Part 2: Onset of irreversible retreat of Amundsen Sea glaciers under current climate on centennial timescales cannot be excluded |
title_full |
The stability of present-day Antarctic grounding lines – Part 2: Onset of irreversible retreat of Amundsen Sea glaciers under current climate on centennial timescales cannot be excluded |
title_fullStr |
The stability of present-day Antarctic grounding lines – Part 2: Onset of irreversible retreat of Amundsen Sea glaciers under current climate on centennial timescales cannot be excluded |
title_full_unstemmed |
The stability of present-day Antarctic grounding lines – Part 2: Onset of irreversible retreat of Amundsen Sea glaciers under current climate on centennial timescales cannot be excluded |
title_sort |
stability of present-day antarctic grounding lines – part 2: onset of irreversible retreat of amundsen sea glaciers under current climate on centennial timescales cannot be excluded |
publisher |
HAL CCSD |
publishDate |
2023 |
url |
https://hal.science/hal-04297038 https://hal.science/hal-04297038/document https://hal.science/hal-04297038/file/tc-17-3761-2023.pdf https://doi.org/10.5194/tc-17-3761-2023 |
genre |
Amundsen Sea Antarc* Antarctic Antarctica Filchner Ronne Ice Shelf Filchner-Ronne Ice Shelf Ice Sheet Ice Shelf Ice Shelves Pine Island Pine Island Glacier Ronne Ice Shelf The Cryosphere Thwaites Glacier |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctica Filchner Ronne Ice Shelf Filchner-Ronne Ice Shelf Ice Sheet Ice Shelf Ice Shelves Pine Island Pine Island Glacier Ronne Ice Shelf The Cryosphere Thwaites Glacier |
op_source |
ISSN: 1994-0424 EISSN: 1994-0416 The Cryosphere https://hal.science/hal-04297038 The Cryosphere, 2023, 17 (9), pp.3761-3783. ⟨10.5194/tc-17-3761-2023⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-17-3761-2023 hal-04297038 https://hal.science/hal-04297038 https://hal.science/hal-04297038/document https://hal.science/hal-04297038/file/tc-17-3761-2023.pdf doi:10.5194/tc-17-3761-2023 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.5194/tc-17-3761-2023 |
container_title |
The Cryosphere |
container_volume |
17 |
container_issue |
9 |
container_start_page |
3761 |
op_container_end_page |
3783 |
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1796938804232192000 |
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ftinsu:oai:HAL:hal-04297038v1 2024-04-21T07:45:12+00:00 The stability of present-day Antarctic grounding lines – Part 2: Onset of irreversible retreat of Amundsen Sea glaciers under current climate on centennial timescales cannot be excluded Reese, Ronja Garbe, Julius Hill, Emily Urruty, Benoît Naughten, Kaitlin Gagliardini, Olivier Durand, Gaël Gillet-Chaulet, Fabien Gudmundsson, G. Hilmar Chandler, David Langebroek, Petra Winkelmann, Ricarda University of Northumbria at Newcastle United Kingdom King‘s College London Institut des Géosciences de l’Environnement (IGE) Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ) Université Grenoble Alpes (UGA) Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ) Lawrence Berkeley National Laboratory Berkeley (LBNL) Bjerknes Centre for Climate Research (BCCR) Department of Biological Sciences Bergen (BIO / UiB) University of Bergen (UiB)-University of Bergen (UiB) Potsdam Institute for Climate Impact Research (PIK) University of Potsdam = Universität Potsdam 2023-09-07 https://hal.science/hal-04297038 https://hal.science/hal-04297038/document https://hal.science/hal-04297038/file/tc-17-3761-2023.pdf https://doi.org/10.5194/tc-17-3761-2023 en eng HAL CCSD Copernicus info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-17-3761-2023 hal-04297038 https://hal.science/hal-04297038 https://hal.science/hal-04297038/document https://hal.science/hal-04297038/file/tc-17-3761-2023.pdf doi:10.5194/tc-17-3761-2023 info:eu-repo/semantics/OpenAccess ISSN: 1994-0424 EISSN: 1994-0416 The Cryosphere https://hal.science/hal-04297038 The Cryosphere, 2023, 17 (9), pp.3761-3783. ⟨10.5194/tc-17-3761-2023⟩ [SDE]Environmental Sciences info:eu-repo/semantics/article Journal articles 2023 ftinsu https://doi.org/10.5194/tc-17-3761-2023 2024-04-05T00:27:42Z International audience Abstract. Observations of ocean-driven grounding-line retreat in the Amundsen Sea Embayment in Antarctica raise the question of an imminent collapse of the West Antarctic Ice Sheet. Here we analyse the committed evolution of Antarctic grounding lines under the present-day climate. To this aim, we first calibrate a sub-shelf melt parameterization, which is derived from an ocean box model, with observed and modelled melt sensitivities to ocean temperature changes, making it suitable for present-day simulations and future sea level projections. Using the new calibration, we run an ensemble of historical simulations from 1850 to 2015 with a state-of-the-art ice sheet model to create model instances of possible present-day ice sheet configurations. Then, we extend the simulations for another 10 000 years to investigate their evolution under constant present-day climate forcing and bathymetry. We test for reversibility of grounding-line movement in the case that large-scale retreat occurs. In the Amundsen Sea Embayment we find irreversible retreat of the Thwaites Glacier for all our parameter combinations and irreversible retreat of the Pine Island Glacier for some admissible parameter combinations. Importantly, an irreversible collapse in the Amundsen Sea Embayment sector is initiated at the earliest between 300 and 500 years in our simulations and is not inevitable yet – as also shown in our companion paper (Part 1, Hill et al., 2023). In other words, the region has not tipped yet. With the assumption of constant present-day climate, the collapse evolves on millennial timescales, with a maximum rate of 0.9 mm a−1 sea-level-equivalent ice volume loss. The contribution to sea level by 2300 is limited to 8 cm with a maximum rate of 0.4 mm a−1 sea-level-equivalent ice volume loss. Furthermore, when allowing ice shelves to regrow to their present geometry, we find that large-scale grounding-line retreat into marine basins upstream of the Filchner–Ronne Ice Shelf and the western Siple Coast is ... Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Antarctica Filchner Ronne Ice Shelf Filchner-Ronne Ice Shelf Ice Sheet Ice Shelf Ice Shelves Pine Island Pine Island Glacier Ronne Ice Shelf The Cryosphere Thwaites Glacier Institut national des sciences de l'Univers: HAL-INSU The Cryosphere 17 9 3761 3783 |