Ice‐Shelf Melt Response to Changing Winds and Glacier Dynamics in the Amundsen Sea Sector, Antarctica
International audience It has been suggested that the coastal Southern Ocean subsurface may warm over the 21st century in response to strengthening and poleward shifting winds, with potential adverse effects on West Antarctic glaciers. However, using a 1/128 ocean regional model that includes ice-sh...
Published in: | Journal of Geophysical Research: Oceans |
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Online Access: | https://hal.science/hal-03001289 https://hal.science/hal-03001289/document https://hal.science/hal-03001289/file/2017JC013059.pdf https://doi.org/10.1002/2017JC013059 |
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ftunigrenoble:oai:HAL:hal-03001289v1 2024-05-12T07:52:49+00:00 Ice‐Shelf Melt Response to Changing Winds and Glacier Dynamics in the Amundsen Sea Sector, Antarctica Donat‐magnin, Marion Jourdain, Nicolas Spence, Paul Le Sommer, Julien Gallée, Hubert Durand, Gaël Institut des Géosciences de l’Environnement (IGE) Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ) University of New South Wales Sydney (UNSW) 2017-12-10 https://hal.science/hal-03001289 https://hal.science/hal-03001289/document https://hal.science/hal-03001289/file/2017JC013059.pdf https://doi.org/10.1002/2017JC013059 en eng HAL CCSD Wiley-Blackwell info:eu-repo/semantics/altIdentifier/doi/10.1002/2017JC013059 hal-03001289 https://hal.science/hal-03001289 https://hal.science/hal-03001289/document https://hal.science/hal-03001289/file/2017JC013059.pdf doi:10.1002/2017JC013059 info:eu-repo/semantics/OpenAccess ISSN: 2169-9275 EISSN: 2169-9291 Journal of Geophysical Research. Oceans https://hal.science/hal-03001289 Journal of Geophysical Research. Oceans, 2017, 122 (12), pp.10206-10224. ⟨10.1002/2017JC013059⟩ [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere info:eu-repo/semantics/article Journal articles 2017 ftunigrenoble https://doi.org/10.1002/2017JC013059 2024-04-18T03:22:40Z International audience It has been suggested that the coastal Southern Ocean subsurface may warm over the 21st century in response to strengthening and poleward shifting winds, with potential adverse effects on West Antarctic glaciers. However, using a 1/128 ocean regional model that includes ice-shelf cavities, we find a more complex response to changing winds in the Amundsen Sea. Simulated offshore subsurface waters get colder under strengthened and poleward shifted winds representative of the SAM projected trend. The buoyancy-driven circulation induced by ice-shelf melt transports this cold offshore anomaly onto the continental shelf, leading to cooling and decreased melt below 450 m. In the vicinity of ice-shelf fronts, Ekman pumping contributes to raise the isotherms in response to changing winds. This effect overwhelms the horizontal transport of colder offshore waters at intermediate depths (between 200 and 450 m), and therefore increases melt rates in the upper part of the ice-shelf cavities, which reinforces the buoyancydriven circulation and further contributes to raise the isotherms. Then, prescribing an extreme grounding line retreat projected for 2100, the total melt rates simulated underneath Thwaites and Pine Island are multiplied by 2.5. Such increase is explained by a larger ocean/ice interface exposed to CDW, which is then amplified by a stronger melt-induced circulation along the ice draft. Our main conclusions are that (1) outputs from ocean models that do not represent ice shelf cavities (e.g., CMIP5 models) should not be directly used to predict the thermal forcing of future ice shelf cavities; (2) coupled ocean/ice sheet models with a velocity-dependent melt formulation are needed for future projections of glaciers experiencing a significant grounding line retreat. Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Pine Island Southern Ocean Université Grenoble Alpes: HAL Amundsen Sea Antarctic Southern Ocean Journal of Geophysical Research: Oceans 122 12 10206 10224 |
institution |
Open Polar |
collection |
Université Grenoble Alpes: HAL |
op_collection_id |
ftunigrenoble |
language |
English |
topic |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere |
spellingShingle |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere Donat‐magnin, Marion Jourdain, Nicolas Spence, Paul Le Sommer, Julien Gallée, Hubert Durand, Gaël Ice‐Shelf Melt Response to Changing Winds and Glacier Dynamics in the Amundsen Sea Sector, Antarctica |
topic_facet |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere |
description |
International audience It has been suggested that the coastal Southern Ocean subsurface may warm over the 21st century in response to strengthening and poleward shifting winds, with potential adverse effects on West Antarctic glaciers. However, using a 1/128 ocean regional model that includes ice-shelf cavities, we find a more complex response to changing winds in the Amundsen Sea. Simulated offshore subsurface waters get colder under strengthened and poleward shifted winds representative of the SAM projected trend. The buoyancy-driven circulation induced by ice-shelf melt transports this cold offshore anomaly onto the continental shelf, leading to cooling and decreased melt below 450 m. In the vicinity of ice-shelf fronts, Ekman pumping contributes to raise the isotherms in response to changing winds. This effect overwhelms the horizontal transport of colder offshore waters at intermediate depths (between 200 and 450 m), and therefore increases melt rates in the upper part of the ice-shelf cavities, which reinforces the buoyancydriven circulation and further contributes to raise the isotherms. Then, prescribing an extreme grounding line retreat projected for 2100, the total melt rates simulated underneath Thwaites and Pine Island are multiplied by 2.5. Such increase is explained by a larger ocean/ice interface exposed to CDW, which is then amplified by a stronger melt-induced circulation along the ice draft. Our main conclusions are that (1) outputs from ocean models that do not represent ice shelf cavities (e.g., CMIP5 models) should not be directly used to predict the thermal forcing of future ice shelf cavities; (2) coupled ocean/ice sheet models with a velocity-dependent melt formulation are needed for future projections of glaciers experiencing a significant grounding line retreat. |
author2 |
Institut des Géosciences de l’Environnement (IGE) Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ) University of New South Wales Sydney (UNSW) |
format |
Article in Journal/Newspaper |
author |
Donat‐magnin, Marion Jourdain, Nicolas Spence, Paul Le Sommer, Julien Gallée, Hubert Durand, Gaël |
author_facet |
Donat‐magnin, Marion Jourdain, Nicolas Spence, Paul Le Sommer, Julien Gallée, Hubert Durand, Gaël |
author_sort |
Donat‐magnin, Marion |
title |
Ice‐Shelf Melt Response to Changing Winds and Glacier Dynamics in the Amundsen Sea Sector, Antarctica |
title_short |
Ice‐Shelf Melt Response to Changing Winds and Glacier Dynamics in the Amundsen Sea Sector, Antarctica |
title_full |
Ice‐Shelf Melt Response to Changing Winds and Glacier Dynamics in the Amundsen Sea Sector, Antarctica |
title_fullStr |
Ice‐Shelf Melt Response to Changing Winds and Glacier Dynamics in the Amundsen Sea Sector, Antarctica |
title_full_unstemmed |
Ice‐Shelf Melt Response to Changing Winds and Glacier Dynamics in the Amundsen Sea Sector, Antarctica |
title_sort |
ice‐shelf melt response to changing winds and glacier dynamics in the amundsen sea sector, antarctica |
publisher |
HAL CCSD |
publishDate |
2017 |
url |
https://hal.science/hal-03001289 https://hal.science/hal-03001289/document https://hal.science/hal-03001289/file/2017JC013059.pdf https://doi.org/10.1002/2017JC013059 |
geographic |
Amundsen Sea Antarctic Southern Ocean |
geographic_facet |
Amundsen Sea Antarctic Southern Ocean |
genre |
Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Pine Island Southern Ocean |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Pine Island Southern Ocean |
op_source |
ISSN: 2169-9275 EISSN: 2169-9291 Journal of Geophysical Research. Oceans https://hal.science/hal-03001289 Journal of Geophysical Research. Oceans, 2017, 122 (12), pp.10206-10224. ⟨10.1002/2017JC013059⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1002/2017JC013059 hal-03001289 https://hal.science/hal-03001289 https://hal.science/hal-03001289/document https://hal.science/hal-03001289/file/2017JC013059.pdf doi:10.1002/2017JC013059 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1002/2017JC013059 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
122 |
container_issue |
12 |
container_start_page |
10206 |
op_container_end_page |
10224 |
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1798838044582739968 |