Exploring ice sheet model sensitivity to ocean thermal forcing and basal sliding using the Community Ice Sheet Model (CISM)
Multi-meter sea level rise (SLR) is thought to be possible within the next few centuries, with most of the uncertainty originating from the Antarctic land ice contribution. One source of uncertainty relates to the ice sheet model initialization. Since ice sheets have a long response time (compared t...
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Online Access: | http://www.osti.gov/servlets/purl/1973811 https://www.osti.gov/biblio/1973811 https://doi.org/10.5194/tc-17-1513-2023 |
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ftosti:oai:osti.gov:1973811 2023-07-30T03:58:43+02:00 Exploring ice sheet model sensitivity to ocean thermal forcing and basal sliding using the Community Ice Sheet Model (CISM) Berdahl, Mira Leguy, Gunter Lipscomb, William H. Urban, Nathan M. Hoffman, Matthew James 2023-05-23 application/pdf http://www.osti.gov/servlets/purl/1973811 https://www.osti.gov/biblio/1973811 https://doi.org/10.5194/tc-17-1513-2023 unknown http://www.osti.gov/servlets/purl/1973811 https://www.osti.gov/biblio/1973811 https://doi.org/10.5194/tc-17-1513-2023 doi:10.5194/tc-17-1513-2023 54 ENVIRONMENTAL SCIENCES 2023 ftosti https://doi.org/10.5194/tc-17-1513-2023 2023-07-11T10:27:07Z Multi-meter sea level rise (SLR) is thought to be possible within the next few centuries, with most of the uncertainty originating from the Antarctic land ice contribution. One source of uncertainty relates to the ice sheet model initialization. Since ice sheets have a long response time (compared to other Earth system components such as the atmosphere), ice sheet model initialization methods can have significant impacts on how the ice sheet responds to future forcings. To assess this, we generated 25 different ice sheet spin-ups, using the Community Ice Sheet Model (CISM) at a 4 km resolution. During each spin-up, we varied two key parameters known to impact the sensitivity of the ice sheet to future forcing: one related to the sensitivity of the ice shelf melt rate to ocean thermal forcing (TF) and the other related to the basal friction. The spin-ups all nudge toward observed thickness and enforce a no-advance calving criterion, such that all final spin-up states resemble observations but differ in their melt and friction parameter settings. Each spin-up was then forced with future ocean thermal forcings from 13 different CMIP6 models under the Shared Socioeconomic Pathway (SSP)5-8.5 emissions scenario and modern climatological surface mass balance data. Our results show that the effects of the ice sheet and ocean parameter settings used during the spin-up are capable of impacting multi-century future SLR predictions by as much as 2 m. By the end of this century, the effects of these choices are more modest, but still significant, with differences of up to 0.2 m of SLR. We have identified a combined ocean and ice parameter space that leads to widespread mass loss within 500 years (low friction and high melt rate sensitivity). To explore temperature thresholds, we also ran a synthetically forced CISM ensemble that is focused on the Amundsen region only. Given certain ocean and ice parameter choices, Amundsen mass loss can be triggered with thermal forcing anomalies between 1.5 and 2 °C relative to the spin-up. ... Other/Unknown Material Antarc* Antarctic Ice Sheet Ice Shelf SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Antarctic The Antarctic The Cryosphere 17 4 1513 1543 |
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Open Polar |
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SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
op_collection_id |
ftosti |
language |
unknown |
topic |
54 ENVIRONMENTAL SCIENCES |
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54 ENVIRONMENTAL SCIENCES Berdahl, Mira Leguy, Gunter Lipscomb, William H. Urban, Nathan M. Hoffman, Matthew James Exploring ice sheet model sensitivity to ocean thermal forcing and basal sliding using the Community Ice Sheet Model (CISM) |
topic_facet |
54 ENVIRONMENTAL SCIENCES |
description |
Multi-meter sea level rise (SLR) is thought to be possible within the next few centuries, with most of the uncertainty originating from the Antarctic land ice contribution. One source of uncertainty relates to the ice sheet model initialization. Since ice sheets have a long response time (compared to other Earth system components such as the atmosphere), ice sheet model initialization methods can have significant impacts on how the ice sheet responds to future forcings. To assess this, we generated 25 different ice sheet spin-ups, using the Community Ice Sheet Model (CISM) at a 4 km resolution. During each spin-up, we varied two key parameters known to impact the sensitivity of the ice sheet to future forcing: one related to the sensitivity of the ice shelf melt rate to ocean thermal forcing (TF) and the other related to the basal friction. The spin-ups all nudge toward observed thickness and enforce a no-advance calving criterion, such that all final spin-up states resemble observations but differ in their melt and friction parameter settings. Each spin-up was then forced with future ocean thermal forcings from 13 different CMIP6 models under the Shared Socioeconomic Pathway (SSP)5-8.5 emissions scenario and modern climatological surface mass balance data. Our results show that the effects of the ice sheet and ocean parameter settings used during the spin-up are capable of impacting multi-century future SLR predictions by as much as 2 m. By the end of this century, the effects of these choices are more modest, but still significant, with differences of up to 0.2 m of SLR. We have identified a combined ocean and ice parameter space that leads to widespread mass loss within 500 years (low friction and high melt rate sensitivity). To explore temperature thresholds, we also ran a synthetically forced CISM ensemble that is focused on the Amundsen region only. Given certain ocean and ice parameter choices, Amundsen mass loss can be triggered with thermal forcing anomalies between 1.5 and 2 °C relative to the spin-up. ... |
author |
Berdahl, Mira Leguy, Gunter Lipscomb, William H. Urban, Nathan M. Hoffman, Matthew James |
author_facet |
Berdahl, Mira Leguy, Gunter Lipscomb, William H. Urban, Nathan M. Hoffman, Matthew James |
author_sort |
Berdahl, Mira |
title |
Exploring ice sheet model sensitivity to ocean thermal forcing and basal sliding using the Community Ice Sheet Model (CISM) |
title_short |
Exploring ice sheet model sensitivity to ocean thermal forcing and basal sliding using the Community Ice Sheet Model (CISM) |
title_full |
Exploring ice sheet model sensitivity to ocean thermal forcing and basal sliding using the Community Ice Sheet Model (CISM) |
title_fullStr |
Exploring ice sheet model sensitivity to ocean thermal forcing and basal sliding using the Community Ice Sheet Model (CISM) |
title_full_unstemmed |
Exploring ice sheet model sensitivity to ocean thermal forcing and basal sliding using the Community Ice Sheet Model (CISM) |
title_sort |
exploring ice sheet model sensitivity to ocean thermal forcing and basal sliding using the community ice sheet model (cism) |
publishDate |
2023 |
url |
http://www.osti.gov/servlets/purl/1973811 https://www.osti.gov/biblio/1973811 https://doi.org/10.5194/tc-17-1513-2023 |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Ice Sheet Ice Shelf |
genre_facet |
Antarc* Antarctic Ice Sheet Ice Shelf |
op_relation |
http://www.osti.gov/servlets/purl/1973811 https://www.osti.gov/biblio/1973811 https://doi.org/10.5194/tc-17-1513-2023 doi:10.5194/tc-17-1513-2023 |
op_doi |
https://doi.org/10.5194/tc-17-1513-2023 |
container_title |
The Cryosphere |
container_volume |
17 |
container_issue |
4 |
container_start_page |
1513 |
op_container_end_page |
1543 |
_version_ |
1772821451937677312 |