Linearity of the Climate System Response to Antarctic Topography Change
Thesis (Master's)--University of Washington, 2020 A hierarchy of general circulation models is used to investigate the linearity of the response of the global climate system to changes in Antarctic topography. Models range in complexity from an atmospheric dry dynamical core to a slab-ocean glo...
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ftunivwashington:oai:digital.lib.washington.edu:1773/45823 2023-05-15T13:38:02+02:00 Linearity of the Climate System Response to Antarctic Topography Change Pauling, Andrew Bitz, Cecilia M. 2020 application/pdf http://hdl.handle.net/1773/45823 en_US eng Pauling_washington_0250O_21759.pdf http://hdl.handle.net/1773/45823 CC BY Antarctica Climate Ice Sheet Atmospheric sciences Thesis 2020 ftunivwashington 2023-03-12T19:00:14Z Thesis (Master's)--University of Washington, 2020 A hierarchy of general circulation models is used to investigate the linearity of the response of the global climate system to changes in Antarctic topography. Models range in complexity from an atmospheric dry dynamical core to a slab-ocean global climate model with idealized West Antarctic ice sheet topography changes and experiments were conducted where topography was either lowered or raised. The range of model complexity used allows the mechanisms responsible for different aspects of the response to be identified. The temperature and circulation response to Antarctic topography change is nearly linear in the dry dynamical core. In all other model configurations the atmosphere consistently warms near the surface over the Southern Ocean, and cools in the stratosphere over the continent, whether topography is raised or lowered. The wind response to changes in ice sheet elevation is linear near the surface, but nonlinear in the upper atmosphere. When topography is lowered in the slab-ocean model configuration the warming is due to enhanced southward atmospheric heat transport. When topography is raised, the warming is associated with an increase in cloud fraction at all levels and downwelling longwave radiation over the Southern Ocean. Finally, experiments were conducted with a fully-coupled global climate model using Antarctic ice sheet topography from a West Antarctic Ice Sheet (WAIS) collapse scenario taken from an ice sheet model, as well as topography that represents half of the change between present day topography and WAIS collapse, and the negative of the change between present day and WAIS collapse topography. The response is largely consistent with the more idealized slab-ocean experiments, but the full depth ocean additionally shows warming throughout the water column in the ocean. In summary these results indicate that ice sheet-climate system feedbacks may differ depending on whether the Antarctic ice sheet is gaining or losing mass. Thesis Antarc* Antarctic Antarctica Ice Sheet Southern Ocean University of Washington, Seattle: ResearchWorks Antarctic Southern Ocean The Antarctic West Antarctic Ice Sheet |
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Open Polar |
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University of Washington, Seattle: ResearchWorks |
op_collection_id |
ftunivwashington |
language |
English |
topic |
Antarctica Climate Ice Sheet Atmospheric sciences |
spellingShingle |
Antarctica Climate Ice Sheet Atmospheric sciences Pauling, Andrew Linearity of the Climate System Response to Antarctic Topography Change |
topic_facet |
Antarctica Climate Ice Sheet Atmospheric sciences |
description |
Thesis (Master's)--University of Washington, 2020 A hierarchy of general circulation models is used to investigate the linearity of the response of the global climate system to changes in Antarctic topography. Models range in complexity from an atmospheric dry dynamical core to a slab-ocean global climate model with idealized West Antarctic ice sheet topography changes and experiments were conducted where topography was either lowered or raised. The range of model complexity used allows the mechanisms responsible for different aspects of the response to be identified. The temperature and circulation response to Antarctic topography change is nearly linear in the dry dynamical core. In all other model configurations the atmosphere consistently warms near the surface over the Southern Ocean, and cools in the stratosphere over the continent, whether topography is raised or lowered. The wind response to changes in ice sheet elevation is linear near the surface, but nonlinear in the upper atmosphere. When topography is lowered in the slab-ocean model configuration the warming is due to enhanced southward atmospheric heat transport. When topography is raised, the warming is associated with an increase in cloud fraction at all levels and downwelling longwave radiation over the Southern Ocean. Finally, experiments were conducted with a fully-coupled global climate model using Antarctic ice sheet topography from a West Antarctic Ice Sheet (WAIS) collapse scenario taken from an ice sheet model, as well as topography that represents half of the change between present day topography and WAIS collapse, and the negative of the change between present day and WAIS collapse topography. The response is largely consistent with the more idealized slab-ocean experiments, but the full depth ocean additionally shows warming throughout the water column in the ocean. In summary these results indicate that ice sheet-climate system feedbacks may differ depending on whether the Antarctic ice sheet is gaining or losing mass. |
author2 |
Bitz, Cecilia M. |
format |
Thesis |
author |
Pauling, Andrew |
author_facet |
Pauling, Andrew |
author_sort |
Pauling, Andrew |
title |
Linearity of the Climate System Response to Antarctic Topography Change |
title_short |
Linearity of the Climate System Response to Antarctic Topography Change |
title_full |
Linearity of the Climate System Response to Antarctic Topography Change |
title_fullStr |
Linearity of the Climate System Response to Antarctic Topography Change |
title_full_unstemmed |
Linearity of the Climate System Response to Antarctic Topography Change |
title_sort |
linearity of the climate system response to antarctic topography change |
publishDate |
2020 |
url |
http://hdl.handle.net/1773/45823 |
geographic |
Antarctic Southern Ocean The Antarctic West Antarctic Ice Sheet |
geographic_facet |
Antarctic Southern Ocean The Antarctic West Antarctic Ice Sheet |
genre |
Antarc* Antarctic Antarctica Ice Sheet Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Southern Ocean |
op_relation |
Pauling_washington_0250O_21759.pdf http://hdl.handle.net/1773/45823 |
op_rights |
CC BY |
_version_ |
1766100649551855616 |