Modeling Glaciers and Ice Sheets in Greenland and Antarctica with an Emphasis on Embedded Modeling and Subglacial Hydrology
Recent observations in Greenland and Antarctica highlight the importance of ice-ocean interaction and the role of subglacial water. These processes influence the mass balance of ice sheets but are currently not well-represented in models used for sea level estimations. Here, we reproduce the observa...
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ftmaineuniv:oai:digitalcommons.library.umaine.edu:etd-3236 2023-06-11T04:06:36+02:00 Modeling Glaciers and Ice Sheets in Greenland and Antarctica with an Emphasis on Embedded Modeling and Subglacial Hydrology Weitz, Nora Amelie 2014-08-01T07:00:00Z application/pdf https://digitalcommons.library.umaine.edu/etd/2196 https://digitalcommons.library.umaine.edu/context/etd/article/3236/viewcontent/WeitzNA2014_OCR.pdf unknown DigitalCommons@UMaine https://digitalcommons.library.umaine.edu/etd/2196 https://digitalcommons.library.umaine.edu/context/etd/article/3236/viewcontent/WeitzNA2014_OCR.pdf Electronic Theses and Dissertations Glaciers Greenland Antarctica Glaciology Hydrology text 2014 ftmaineuniv 2023-05-04T18:02:14Z Recent observations in Greenland and Antarctica highlight the importance of ice-ocean interaction and the role of subglacial water. These processes influence the mass balance of ice sheets but are currently not well-represented in models used for sea level estimations. Here, we reproduce the observations numerically to investigate their influence on ice dynamics and improve prognostic modeling. Recent acceleration and retreat of several Greenland outlet glaciers have led to significant mass loss from the ice sheet. The mechanisms responsible for triggering the change in dynamics are poorly understood and their interactions uncertain. Here, the dynamics of Helheim Glacier are simulated with real climate input to investigate the glacier’s response to realistic forcings. Results show that changes in surface mass balance, calving events or submarine melt rates at the grounding line can individually reproduce the observed behavior of the glacier. Acceleration of ice streams is also observed in Antarctica, where large subglacial drainage networks exist. The acceleration of Byrd Glacier has been linked to a subglacial lake discharge event and lasted at least nine months. How does basal water influence ice sheet flow and ice stream dynamics in East Antarctica? Simulating the acceleration of Byrd Glacier with a basal water flow model incorporated in the ice sheet model shows there is an active basal water system underneath the Byrd catchment area and that sliding processes contribute to the overall velocity field. Widespread subglacial water systems are also observed under the ablation zone of the Greenland Ice Sheet. Summer speed-up of the ice sheet due to enhanced basal sliding is linked to the seasonal increase of surface melt water production. A numerical ice sheet model coupled to a subglacial water model is used to investigate the influence of seasonal melt water on the sliding process. We find that ice acceleration declines quickly as drainage systems adapt their capacity, and that the process is strongly ... Text Antarc* Antarctica Byrd Glacier East Antarctica glacier Greenland Ice Sheet The University of Maine: DigitalCommons@UMaine East Antarctica Greenland Byrd Byrd Glacier ENVELOPE(160.333,160.333,-80.250,-80.250) |
institution |
Open Polar |
collection |
The University of Maine: DigitalCommons@UMaine |
op_collection_id |
ftmaineuniv |
language |
unknown |
topic |
Glaciers Greenland Antarctica Glaciology Hydrology |
spellingShingle |
Glaciers Greenland Antarctica Glaciology Hydrology Weitz, Nora Amelie Modeling Glaciers and Ice Sheets in Greenland and Antarctica with an Emphasis on Embedded Modeling and Subglacial Hydrology |
topic_facet |
Glaciers Greenland Antarctica Glaciology Hydrology |
description |
Recent observations in Greenland and Antarctica highlight the importance of ice-ocean interaction and the role of subglacial water. These processes influence the mass balance of ice sheets but are currently not well-represented in models used for sea level estimations. Here, we reproduce the observations numerically to investigate their influence on ice dynamics and improve prognostic modeling. Recent acceleration and retreat of several Greenland outlet glaciers have led to significant mass loss from the ice sheet. The mechanisms responsible for triggering the change in dynamics are poorly understood and their interactions uncertain. Here, the dynamics of Helheim Glacier are simulated with real climate input to investigate the glacier’s response to realistic forcings. Results show that changes in surface mass balance, calving events or submarine melt rates at the grounding line can individually reproduce the observed behavior of the glacier. Acceleration of ice streams is also observed in Antarctica, where large subglacial drainage networks exist. The acceleration of Byrd Glacier has been linked to a subglacial lake discharge event and lasted at least nine months. How does basal water influence ice sheet flow and ice stream dynamics in East Antarctica? Simulating the acceleration of Byrd Glacier with a basal water flow model incorporated in the ice sheet model shows there is an active basal water system underneath the Byrd catchment area and that sliding processes contribute to the overall velocity field. Widespread subglacial water systems are also observed under the ablation zone of the Greenland Ice Sheet. Summer speed-up of the ice sheet due to enhanced basal sliding is linked to the seasonal increase of surface melt water production. A numerical ice sheet model coupled to a subglacial water model is used to investigate the influence of seasonal melt water on the sliding process. We find that ice acceleration declines quickly as drainage systems adapt their capacity, and that the process is strongly ... |
format |
Text |
author |
Weitz, Nora Amelie |
author_facet |
Weitz, Nora Amelie |
author_sort |
Weitz, Nora Amelie |
title |
Modeling Glaciers and Ice Sheets in Greenland and Antarctica with an Emphasis on Embedded Modeling and Subglacial Hydrology |
title_short |
Modeling Glaciers and Ice Sheets in Greenland and Antarctica with an Emphasis on Embedded Modeling and Subglacial Hydrology |
title_full |
Modeling Glaciers and Ice Sheets in Greenland and Antarctica with an Emphasis on Embedded Modeling and Subglacial Hydrology |
title_fullStr |
Modeling Glaciers and Ice Sheets in Greenland and Antarctica with an Emphasis on Embedded Modeling and Subglacial Hydrology |
title_full_unstemmed |
Modeling Glaciers and Ice Sheets in Greenland and Antarctica with an Emphasis on Embedded Modeling and Subglacial Hydrology |
title_sort |
modeling glaciers and ice sheets in greenland and antarctica with an emphasis on embedded modeling and subglacial hydrology |
publisher |
DigitalCommons@UMaine |
publishDate |
2014 |
url |
https://digitalcommons.library.umaine.edu/etd/2196 https://digitalcommons.library.umaine.edu/context/etd/article/3236/viewcontent/WeitzNA2014_OCR.pdf |
long_lat |
ENVELOPE(160.333,160.333,-80.250,-80.250) |
geographic |
East Antarctica Greenland Byrd Byrd Glacier |
geographic_facet |
East Antarctica Greenland Byrd Byrd Glacier |
genre |
Antarc* Antarctica Byrd Glacier East Antarctica glacier Greenland Ice Sheet |
genre_facet |
Antarc* Antarctica Byrd Glacier East Antarctica glacier Greenland Ice Sheet |
op_source |
Electronic Theses and Dissertations |
op_relation |
https://digitalcommons.library.umaine.edu/etd/2196 https://digitalcommons.library.umaine.edu/context/etd/article/3236/viewcontent/WeitzNA2014_OCR.pdf |
_version_ |
1768378618649509888 |