Uncertainty quantification of the multi-centennial response of the Antarctic ice sheet to climate change
<p>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-sh...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2019-04-01
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| Series: | The Cryosphere |
| Online Access: | https://www.the-cryosphere.net/13/1349/2019/tc-13-1349-2019.pdf |
| _version_ | 1818429121771864064 |
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| author | K. Bulthuis K. Bulthuis M. Arnst S. Sun F. Pattyn |
| author_facet | K. Bulthuis K. Bulthuis M. Arnst S. Sun F. Pattyn |
| author_sort | K. Bulthuis |
| collection | DOAJ |
| description | <p>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.</p> |
| first_indexed | 2024-12-14T15:12:29Z |
| format | Article |
| id | doaj.art-a797dd3287294411a5f8f377dea7fd06 |
| institution | Directory Open Access Journal |
| issn | 1994-0416 1994-0424 |
| language | English |
| last_indexed | 2024-12-14T15:12:29Z |
| publishDate | 2019-04-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | The Cryosphere |
| spelling | doaj.art-a797dd3287294411a5f8f377dea7fd062022-12-21T22:56:29ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242019-04-01131349138010.5194/tc-13-1349-2019Uncertainty quantification of the multi-centennial response of the Antarctic ice sheet to climate changeK. Bulthuis0K. Bulthuis1M. Arnst2S. Sun3F. Pattyn4Computational and Stochastic Modeling, Aerospace and Mechanical Engineering, Université de Liège, Allée de la Découverte 9, Quartier Polytech 1, 4000 Liège, BelgiumLaboratoire de Glaciologie, Department of Geosciences, Environment and Society, Université Libre de Bruxelles, Av. F.D. Roosevelt 50, 1050 Brussels, BelgiumComputational and Stochastic Modeling, Aerospace and Mechanical Engineering, Université de Liège, Allée de la Découverte 9, Quartier Polytech 1, 4000 Liège, BelgiumLaboratoire de Glaciologie, Department of Geosciences, Environment and Society, Université Libre de Bruxelles, Av. F.D. Roosevelt 50, 1050 Brussels, BelgiumLaboratoire de Glaciologie, Department of Geosciences, Environment and Society, Université Libre de Bruxelles, Av. F.D. Roosevelt 50, 1050 Brussels, Belgium<p>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.</p>https://www.the-cryosphere.net/13/1349/2019/tc-13-1349-2019.pdf |
| spellingShingle | K. Bulthuis K. Bulthuis M. Arnst S. Sun F. Pattyn Uncertainty quantification of the multi-centennial response of the Antarctic ice sheet to climate change The Cryosphere |
| title | 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_short | 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 |
| url | https://www.the-cryosphere.net/13/1349/2019/tc-13-1349-2019.pdf |
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