Uncertainty quantification of the multi-centennial response of the Antarctic ice sheet to climate change
Ice loss from the Antarctic ice sheet (AIS) is expected to become the major contributor to sea level in the next centuries. Projections of the AIS response to climate change based on numerical ice-sheet models remain challenging due to the complexity of physical processes involved in ice-sheet dynam...
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ftcopernicus:oai:publications.copernicus.org:tc72254 2023-05-15T13:55:28+02:00 Uncertainty quantification of the multi-centennial response of the Antarctic ice sheet to climate change Bulthuis, Kevin Arnst, Maarten Sun, Sainan Pattyn, Frank 2019-04-24 application/pdf https://doi.org/10.5194/tc-13-1349-2019 https://tc.copernicus.org/articles/13/1349/2019/ eng eng doi:10.5194/tc-13-1349-2019 https://tc.copernicus.org/articles/13/1349/2019/ eISSN: 1994-0424 Text 2019 ftcopernicus https://doi.org/10.5194/tc-13-1349-2019 2020-07-20T16:22:51Z Ice loss from the Antarctic ice sheet (AIS) is expected to become the major contributor to sea level in the next centuries. Projections of the AIS response to climate change based on numerical ice-sheet models remain challenging due to the complexity of physical processes involved in ice-sheet dynamics, including instability mechanisms that can destabilise marine basins with retrograde slopes. Moreover, uncertainties in ice-sheet models limit the ability to provide accurate sea-level rise projections. Here, we apply probabilistic methods to a hybrid ice-sheet model to investigate the influence of several sources of uncertainty, namely sources of uncertainty in atmospheric forcing, basal sliding, grounding-line flux parameterisation, calving, sub-shelf melting, ice-shelf rheology and bedrock relaxation, on the continental response of the Antarctic ice sheet to climate change over the next millennium. We provide probabilistic projections of sea-level rise and grounding-line retreat, and we carry out stochastic sensitivity analysis to determine the most influential sources of uncertainty. We find that all investigated sources of uncertainty, except bedrock relaxation time, contribute to the uncertainty in the projections. We show that the sensitivity of the projections to uncertainties increases and the contribution of the uncertainty in sub-shelf melting to the uncertainty in the projections becomes more and more dominant as atmospheric and oceanic temperatures rise, with a contribution to the uncertainty in sea-level rise projections that goes from 5 % to 25 % in RCP 2.6 to more than 90 % in RCP 8.5. We show that the significance of the AIS contribution to sea level is controlled by the marine ice-sheet instability (MISI) in marine basins, with the biggest contribution stemming from the more vulnerable West Antarctic ice sheet. We find that, irrespective of parametric uncertainty, the strongly mitigated RCP 2.6 scenario prevents the collapse of the West Antarctic ice sheet, that in both the RCP 4.5 and RCP 6.0 scenarios the occurrence of MISI in marine basins is more sensitive to parametric uncertainty, and that, almost irrespective of parametric uncertainty, RCP 8.5 triggers the collapse of the West Antarctic ice sheet. Text Antarc* Antarctic Ice Sheet Ice Shelf Copernicus Publications: E-Journals Antarctic Misi ENVELOPE(26.683,26.683,66.617,66.617) The Antarctic West Antarctic Ice Sheet The Cryosphere 13 4 1349 1380 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Ice loss from the Antarctic ice sheet (AIS) is expected to become the major contributor to sea level in the next centuries. Projections of the AIS response to climate change based on numerical ice-sheet models remain challenging due to the complexity of physical processes involved in ice-sheet dynamics, including instability mechanisms that can destabilise marine basins with retrograde slopes. Moreover, uncertainties in ice-sheet models limit the ability to provide accurate sea-level rise projections. Here, we apply probabilistic methods to a hybrid ice-sheet model to investigate the influence of several sources of uncertainty, namely sources of uncertainty in atmospheric forcing, basal sliding, grounding-line flux parameterisation, calving, sub-shelf melting, ice-shelf rheology and bedrock relaxation, on the continental response of the Antarctic ice sheet to climate change over the next millennium. We provide probabilistic projections of sea-level rise and grounding-line retreat, and we carry out stochastic sensitivity analysis to determine the most influential sources of uncertainty. We find that all investigated sources of uncertainty, except bedrock relaxation time, contribute to the uncertainty in the projections. We show that the sensitivity of the projections to uncertainties increases and the contribution of the uncertainty in sub-shelf melting to the uncertainty in the projections becomes more and more dominant as atmospheric and oceanic temperatures rise, with a contribution to the uncertainty in sea-level rise projections that goes from 5 % to 25 % in RCP 2.6 to more than 90 % in RCP 8.5. We show that the significance of the AIS contribution to sea level is controlled by the marine ice-sheet instability (MISI) in marine basins, with the biggest contribution stemming from the more vulnerable West Antarctic ice sheet. We find that, irrespective of parametric uncertainty, the strongly mitigated RCP 2.6 scenario prevents the collapse of the West Antarctic ice sheet, that in both the RCP 4.5 and RCP 6.0 scenarios the occurrence of MISI in marine basins is more sensitive to parametric uncertainty, and that, almost irrespective of parametric uncertainty, RCP 8.5 triggers the collapse of the West Antarctic ice sheet. |
format |
Text |
author |
Bulthuis, Kevin Arnst, Maarten Sun, Sainan Pattyn, Frank |
spellingShingle |
Bulthuis, Kevin Arnst, Maarten Sun, Sainan Pattyn, Frank Uncertainty quantification of the multi-centennial response of the Antarctic ice sheet to climate change |
author_facet |
Bulthuis, Kevin Arnst, Maarten Sun, Sainan Pattyn, Frank |
author_sort |
Bulthuis, Kevin |
title |
Uncertainty quantification of the multi-centennial response of the Antarctic ice sheet to climate change |
title_short |
Uncertainty quantification of the multi-centennial response of the Antarctic ice sheet to climate change |
title_full |
Uncertainty quantification of the multi-centennial response of the Antarctic ice sheet to climate change |
title_fullStr |
Uncertainty quantification of the multi-centennial response of the Antarctic ice sheet to climate change |
title_full_unstemmed |
Uncertainty quantification of the multi-centennial response of the Antarctic ice sheet to climate change |
title_sort |
uncertainty quantification of the multi-centennial response of the antarctic ice sheet to climate change |
publishDate |
2019 |
url |
https://doi.org/10.5194/tc-13-1349-2019 https://tc.copernicus.org/articles/13/1349/2019/ |
long_lat |
ENVELOPE(26.683,26.683,66.617,66.617) |
geographic |
Antarctic Misi The Antarctic West Antarctic Ice Sheet |
geographic_facet |
Antarctic Misi The Antarctic West Antarctic Ice Sheet |
genre |
Antarc* Antarctic Ice Sheet Ice Shelf |
genre_facet |
Antarc* Antarctic Ice Sheet Ice Shelf |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-13-1349-2019 https://tc.copernicus.org/articles/13/1349/2019/ |
op_doi |
https://doi.org/10.5194/tc-13-1349-2019 |
container_title |
The Cryosphere |
container_volume |
13 |
container_issue |
4 |
container_start_page |
1349 |
op_container_end_page |
1380 |
_version_ |
1766262115238150144 |