ISMIP6 projections of ocean-forced Antarctic Ice Sheet evolution using the Community Ice Sheet Model
The future retreat rate for marine-based regions of the Antarctic Ice Sheet is one of the largest uncertainties in sea-level projections. The Ice Sheet Model Intercomparison Project for CMIP6 (ISMIP6) aims to improve projections and quantify uncertainties by running an ensemble of ice sheet models w...
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ftcopernicus:oai:publications.copernicus.org:tcd82801 2023-05-15T13:55:28+02:00 ISMIP6 projections of ocean-forced Antarctic Ice Sheet evolution using the Community Ice Sheet Model Lipscomb, William H. Leguy, Gunter R. Jourdain, Nicolas C. Asay-Davis, Xylar S. Seroussi, Hélène Nowicki, Sophie 2020-01-14 application/pdf https://doi.org/10.5194/tc-2019-334 https://tc.copernicus.org/preprints/tc-2019-334/ eng eng doi:10.5194/tc-2019-334 https://tc.copernicus.org/preprints/tc-2019-334/ eISSN: 1994-0424 Text 2020 ftcopernicus https://doi.org/10.5194/tc-2019-334 2020-07-20T16:22:29Z The future retreat rate for marine-based regions of the Antarctic Ice Sheet is one of the largest uncertainties in sea-level projections. The Ice Sheet Model Intercomparison Project for CMIP6 (ISMIP6) aims to improve projections and quantify uncertainties by running an ensemble of ice sheet models with atmosphere and ocean forcing derived from global climate models. Here, ISMIP6 projections of ocean-forced Antarctic Ice Sheet evolution are illustrated using the Community Ice Sheet Model (CISM). Using multiple combinations of sub-ice-shelf melt parameterizations and calibrations, CISM is spun up to steady state over many millennia. During the spin-up, basal friction parameters and basin-scale thermal forcing corrections are adjusted to nudge the ice thickness toward observed values. The model is then run forward for 500 years, applying ocean thermal forcing anomalies from six climate models. In all simulations, the ocean forcing triggers long-term retreat of the West Antarctic Ice Sheet, including the Amundsen, Filchner-Ronne, and Ross Basins. Mass loss accelerates late in the 21st century and rises steadily over the next several centuries without leveling off. The resulting ocean-forced SLR at year 2500 varies from about 10 cm to nearly 2 m, depending on the melt scheme and model forcing. Relatively little ice loss is simulated in East Antarctica. Large uncertainties remain, as a result of parameterized basal melt rates, missing ocean and ice sheet physics, and the lack of ice–ocean coupling. Text Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelf Copernicus Publications: E-Journals Antarctic East Antarctica The Antarctic West Antarctic Ice Sheet |
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Copernicus Publications: E-Journals |
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ftcopernicus |
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English |
description |
The future retreat rate for marine-based regions of the Antarctic Ice Sheet is one of the largest uncertainties in sea-level projections. The Ice Sheet Model Intercomparison Project for CMIP6 (ISMIP6) aims to improve projections and quantify uncertainties by running an ensemble of ice sheet models with atmosphere and ocean forcing derived from global climate models. Here, ISMIP6 projections of ocean-forced Antarctic Ice Sheet evolution are illustrated using the Community Ice Sheet Model (CISM). Using multiple combinations of sub-ice-shelf melt parameterizations and calibrations, CISM is spun up to steady state over many millennia. During the spin-up, basal friction parameters and basin-scale thermal forcing corrections are adjusted to nudge the ice thickness toward observed values. The model is then run forward for 500 years, applying ocean thermal forcing anomalies from six climate models. In all simulations, the ocean forcing triggers long-term retreat of the West Antarctic Ice Sheet, including the Amundsen, Filchner-Ronne, and Ross Basins. Mass loss accelerates late in the 21st century and rises steadily over the next several centuries without leveling off. The resulting ocean-forced SLR at year 2500 varies from about 10 cm to nearly 2 m, depending on the melt scheme and model forcing. Relatively little ice loss is simulated in East Antarctica. Large uncertainties remain, as a result of parameterized basal melt rates, missing ocean and ice sheet physics, and the lack of ice–ocean coupling. |
format |
Text |
author |
Lipscomb, William H. Leguy, Gunter R. Jourdain, Nicolas C. Asay-Davis, Xylar S. Seroussi, Hélène Nowicki, Sophie |
spellingShingle |
Lipscomb, William H. Leguy, Gunter R. Jourdain, Nicolas C. Asay-Davis, Xylar S. Seroussi, Hélène Nowicki, Sophie ISMIP6 projections of ocean-forced Antarctic Ice Sheet evolution using the Community Ice Sheet Model |
author_facet |
Lipscomb, William H. Leguy, Gunter R. Jourdain, Nicolas C. Asay-Davis, Xylar S. Seroussi, Hélène Nowicki, Sophie |
author_sort |
Lipscomb, William H. |
title |
ISMIP6 projections of ocean-forced Antarctic Ice Sheet evolution using the Community Ice Sheet Model |
title_short |
ISMIP6 projections of ocean-forced Antarctic Ice Sheet evolution using the Community Ice Sheet Model |
title_full |
ISMIP6 projections of ocean-forced Antarctic Ice Sheet evolution using the Community Ice Sheet Model |
title_fullStr |
ISMIP6 projections of ocean-forced Antarctic Ice Sheet evolution using the Community Ice Sheet Model |
title_full_unstemmed |
ISMIP6 projections of ocean-forced Antarctic Ice Sheet evolution using the Community Ice Sheet Model |
title_sort |
ismip6 projections of ocean-forced antarctic ice sheet evolution using the community ice sheet model |
publishDate |
2020 |
url |
https://doi.org/10.5194/tc-2019-334 https://tc.copernicus.org/preprints/tc-2019-334/ |
geographic |
Antarctic East Antarctica The Antarctic West Antarctic Ice Sheet |
geographic_facet |
Antarctic East Antarctica The Antarctic West Antarctic Ice Sheet |
genre |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelf |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelf |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-2019-334 https://tc.copernicus.org/preprints/tc-2019-334/ |
op_doi |
https://doi.org/10.5194/tc-2019-334 |
_version_ |
1766262102924722176 |