The Antarctic Ice Sheet response to glacial millennial-scale variability
The Antarctic Ice Sheet (AIS) is the largest ice sheet on Earth and hence a major potential contributor to future global sea-level rise. A wealth of studies suggest that increasing oceanic temperatures could cause a collapse of its marine-based western sector, the West Antarctic Ice Sheet, through t...
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ftcopernicus:oai:publications.copernicus.org:cp70697 2023-05-15T13:55:28+02:00 The Antarctic Ice Sheet response to glacial millennial-scale variability Blasco, Javier Tabone, Ilaria Alvarez-Solas, Jorge Robinson, Alexander Montoya, Marisa 2019-01-17 application/pdf https://doi.org/10.5194/cp-15-121-2019 https://cp.copernicus.org/articles/15/121/2019/ eng eng doi:10.5194/cp-15-121-2019 https://cp.copernicus.org/articles/15/121/2019/ eISSN: 1814-9332 Text 2019 ftcopernicus https://doi.org/10.5194/cp-15-121-2019 2020-07-20T16:22:58Z The Antarctic Ice Sheet (AIS) is the largest ice sheet on Earth and hence a major potential contributor to future global sea-level rise. A wealth of studies suggest that increasing oceanic temperatures could cause a collapse of its marine-based western sector, the West Antarctic Ice Sheet, through the mechanism of marine ice-sheet instability, leading to a sea-level increase of 3–5 m . Thus, it is crucial to constrain the sensitivity of the AIS to rapid climate changes. The last glacial period is an ideal benchmark period for this purpose as it was punctuated by abrupt Dansgaard–Oeschger events at millennial timescales. Because their center of action was in the North Atlantic, where their climate impacts were largest, modeling studies have mainly focused on the millennial-scale evolution of Northern Hemisphere (NH) paleo ice sheets. Sea-level reconstructions attribute the origin of millennial-scale sea-level variations mainly to NH paleo ice sheets, with a minor but not negligible role of the AIS. Here we investigate the AIS response to millennial-scale climate variability for the first time. To this end we use a three-dimensional, thermomechanical hybrid, ice sheet–shelf model. Different oceanic sensitivities are tested and the sea-level equivalent (SLE) contributions computed. We find that whereas atmospheric variability has no appreciable effect on the AIS, changes in submarine melting rates can have a strong impact on it. We show that in contrast to the widespread assumption that the AIS is a slow reactive and static ice sheet that responds at orbital timescales only, it can lead to ice discharges of around 6 m SLE, involving substantial grounding line migrations at millennial timescales. Text Antarc* Antarctic Dansgaard-Oeschger events Ice Sheet North Atlantic Copernicus Publications: E-Journals Antarctic The Antarctic West Antarctic Ice Sheet Climate of the Past 15 1 121 133 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
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English |
description |
The Antarctic Ice Sheet (AIS) is the largest ice sheet on Earth and hence a major potential contributor to future global sea-level rise. A wealth of studies suggest that increasing oceanic temperatures could cause a collapse of its marine-based western sector, the West Antarctic Ice Sheet, through the mechanism of marine ice-sheet instability, leading to a sea-level increase of 3–5 m . Thus, it is crucial to constrain the sensitivity of the AIS to rapid climate changes. The last glacial period is an ideal benchmark period for this purpose as it was punctuated by abrupt Dansgaard–Oeschger events at millennial timescales. Because their center of action was in the North Atlantic, where their climate impacts were largest, modeling studies have mainly focused on the millennial-scale evolution of Northern Hemisphere (NH) paleo ice sheets. Sea-level reconstructions attribute the origin of millennial-scale sea-level variations mainly to NH paleo ice sheets, with a minor but not negligible role of the AIS. Here we investigate the AIS response to millennial-scale climate variability for the first time. To this end we use a three-dimensional, thermomechanical hybrid, ice sheet–shelf model. Different oceanic sensitivities are tested and the sea-level equivalent (SLE) contributions computed. We find that whereas atmospheric variability has no appreciable effect on the AIS, changes in submarine melting rates can have a strong impact on it. We show that in contrast to the widespread assumption that the AIS is a slow reactive and static ice sheet that responds at orbital timescales only, it can lead to ice discharges of around 6 m SLE, involving substantial grounding line migrations at millennial timescales. |
format |
Text |
author |
Blasco, Javier Tabone, Ilaria Alvarez-Solas, Jorge Robinson, Alexander Montoya, Marisa |
spellingShingle |
Blasco, Javier Tabone, Ilaria Alvarez-Solas, Jorge Robinson, Alexander Montoya, Marisa The Antarctic Ice Sheet response to glacial millennial-scale variability |
author_facet |
Blasco, Javier Tabone, Ilaria Alvarez-Solas, Jorge Robinson, Alexander Montoya, Marisa |
author_sort |
Blasco, Javier |
title |
The Antarctic Ice Sheet response to glacial millennial-scale variability |
title_short |
The Antarctic Ice Sheet response to glacial millennial-scale variability |
title_full |
The Antarctic Ice Sheet response to glacial millennial-scale variability |
title_fullStr |
The Antarctic Ice Sheet response to glacial millennial-scale variability |
title_full_unstemmed |
The Antarctic Ice Sheet response to glacial millennial-scale variability |
title_sort |
antarctic ice sheet response to glacial millennial-scale variability |
publishDate |
2019 |
url |
https://doi.org/10.5194/cp-15-121-2019 https://cp.copernicus.org/articles/15/121/2019/ |
geographic |
Antarctic The Antarctic West Antarctic Ice Sheet |
geographic_facet |
Antarctic The Antarctic West Antarctic Ice Sheet |
genre |
Antarc* Antarctic Dansgaard-Oeschger events Ice Sheet North Atlantic |
genre_facet |
Antarc* Antarctic Dansgaard-Oeschger events Ice Sheet North Atlantic |
op_source |
eISSN: 1814-9332 |
op_relation |
doi:10.5194/cp-15-121-2019 https://cp.copernicus.org/articles/15/121/2019/ |
op_doi |
https://doi.org/10.5194/cp-15-121-2019 |
container_title |
Climate of the Past |
container_volume |
15 |
container_issue |
1 |
container_start_page |
121 |
op_container_end_page |
133 |
_version_ |
1766262119856078848 |