Exploring the impact of atmospheric forcing and basal drag on theAntarctic Ice Sheet under Last Glacial Maximum conditions
Little is known about the distribution of ice in the Antarctic Ice Sheet (AIS) during the Last Glacial Maximum (LGM). Whereas marine and terrestrial geological data indicate that the grounded ice advanced to a position close to the continental-shelf break, the total ice volume is unclear. Glacial bo...
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ftzenodo:oai:zenodo.org:4452012 2024-09-15T17:48:36+00:00 Exploring the impact of atmospheric forcing and basal drag on theAntarctic Ice Sheet under Last Glacial Maximum conditions Blasco, Javier Alvarez-Solas, Jorge Robinson, Alexander Montoya, Marisa 2021-01-18 https://doi.org/10.5194/tc-15-215-2021 eng eng Zenodo https://zenodo.org/communities/eu https://doi.org/10.5194/tc-15-215-2021 oai:zenodo.org:4452012 info:eu-repo/semantics/openAccess Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode Antarctic Ice Sheet Last Glacial Maximum basal friction info:eu-repo/semantics/article 2021 ftzenodo https://doi.org/10.5194/tc-15-215-2021 2024-07-26T22:20:04Z Little is known about the distribution of ice in the Antarctic Ice Sheet (AIS) during the Last Glacial Maximum (LGM). Whereas marine and terrestrial geological data indicate that the grounded ice advanced to a position close to the continental-shelf break, the total ice volume is unclear. Glacial boundary conditions are potentially important sources of uncertainty, in particular basal friction and climatic boundary conditions. Basal friction exerts a strong control on the large-scale dynamics of the ice sheet and thus affects its size and is not well constrained. Glacial climatic boundary conditions determine the net accumulation and ice temperature and are also poorly known. Here we explore the effect of the uncertainty in both features on the total simulated ice storage of the AIS at the LGM. For this purpose we use a hybrid ice sheet shelf model that is forced with different basal drag choices and glacial background climatic conditions obtained from the LGM ensemble climate simulations of the third phase of the Paleoclimate Modelling Intercomparison Project (PMIP3). Overall, we find that the spread in the simulated ice volume for the tested basal drag parameterizations is about the same range as for the different general circulation model (GCM) forcings (4 to 6 m sea level equivalent). For a wide range of plausible basal friction configurations, the simulated ice dynamics vary widely but all simulations produce fully extended ice sheets towards the continental-shelf break. More dynamically active ice sheets correspond to lower ice volumes, while they remain consistent with the available constraints on ice extent. Thus, this work points to the possibility of an AIS with very active ice streams during the LGM. In addition, we find that the surface boundary temperature field plays a crucial role in determining the ice extent through its effect on viscosity. For ice sheets of a similar extent and comparable dynamics, we find that the precipitation field determines the total AIS volume. However, precipitation is ... Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Zenodo The Cryosphere 15 1 215 231 |
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op_collection_id |
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language |
English |
topic |
Antarctic Ice Sheet Last Glacial Maximum basal friction |
spellingShingle |
Antarctic Ice Sheet Last Glacial Maximum basal friction Blasco, Javier Alvarez-Solas, Jorge Robinson, Alexander Montoya, Marisa Exploring the impact of atmospheric forcing and basal drag on theAntarctic Ice Sheet under Last Glacial Maximum conditions |
topic_facet |
Antarctic Ice Sheet Last Glacial Maximum basal friction |
description |
Little is known about the distribution of ice in the Antarctic Ice Sheet (AIS) during the Last Glacial Maximum (LGM). Whereas marine and terrestrial geological data indicate that the grounded ice advanced to a position close to the continental-shelf break, the total ice volume is unclear. Glacial boundary conditions are potentially important sources of uncertainty, in particular basal friction and climatic boundary conditions. Basal friction exerts a strong control on the large-scale dynamics of the ice sheet and thus affects its size and is not well constrained. Glacial climatic boundary conditions determine the net accumulation and ice temperature and are also poorly known. Here we explore the effect of the uncertainty in both features on the total simulated ice storage of the AIS at the LGM. For this purpose we use a hybrid ice sheet shelf model that is forced with different basal drag choices and glacial background climatic conditions obtained from the LGM ensemble climate simulations of the third phase of the Paleoclimate Modelling Intercomparison Project (PMIP3). Overall, we find that the spread in the simulated ice volume for the tested basal drag parameterizations is about the same range as for the different general circulation model (GCM) forcings (4 to 6 m sea level equivalent). For a wide range of plausible basal friction configurations, the simulated ice dynamics vary widely but all simulations produce fully extended ice sheets towards the continental-shelf break. More dynamically active ice sheets correspond to lower ice volumes, while they remain consistent with the available constraints on ice extent. Thus, this work points to the possibility of an AIS with very active ice streams during the LGM. In addition, we find that the surface boundary temperature field plays a crucial role in determining the ice extent through its effect on viscosity. For ice sheets of a similar extent and comparable dynamics, we find that the precipitation field determines the total AIS volume. However, precipitation is ... |
format |
Article in Journal/Newspaper |
author |
Blasco, Javier Alvarez-Solas, Jorge Robinson, Alexander Montoya, Marisa |
author_facet |
Blasco, Javier Alvarez-Solas, Jorge Robinson, Alexander Montoya, Marisa |
author_sort |
Blasco, Javier |
title |
Exploring the impact of atmospheric forcing and basal drag on theAntarctic Ice Sheet under Last Glacial Maximum conditions |
title_short |
Exploring the impact of atmospheric forcing and basal drag on theAntarctic Ice Sheet under Last Glacial Maximum conditions |
title_full |
Exploring the impact of atmospheric forcing and basal drag on theAntarctic Ice Sheet under Last Glacial Maximum conditions |
title_fullStr |
Exploring the impact of atmospheric forcing and basal drag on theAntarctic Ice Sheet under Last Glacial Maximum conditions |
title_full_unstemmed |
Exploring the impact of atmospheric forcing and basal drag on theAntarctic Ice Sheet under Last Glacial Maximum conditions |
title_sort |
exploring the impact of atmospheric forcing and basal drag on theantarctic ice sheet under last glacial maximum conditions |
publisher |
Zenodo |
publishDate |
2021 |
url |
https://doi.org/10.5194/tc-15-215-2021 |
genre |
Antarc* Antarctic Ice Sheet |
genre_facet |
Antarc* Antarctic Ice Sheet |
op_relation |
https://zenodo.org/communities/eu https://doi.org/10.5194/tc-15-215-2021 oai:zenodo.org:4452012 |
op_rights |
info:eu-repo/semantics/openAccess Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode |
op_doi |
https://doi.org/10.5194/tc-15-215-2021 |
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The Cryosphere |
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15 |
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1 |
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215 |
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231 |
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1810290005149483008 |