A confined–unconfined aquifer model for subglacial hydrology and its application to the Northeast Greenland Ice Stream
Subglacial hydrology plays an important role in ice sheet dynamics as it determines the sliding velocity. It also drives freshwater into the ocean, leading to undercutting of calving fronts by plumes. Modeling subglacial water has been a challenge for decades. Only recently have new approaches been...
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Copernicus Publications
2018
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fttriple:oai:gotriple.eu:oai:doaj.org/article:0a4d7995c69648a78e56cbdb351e541e 2023-05-15T16:27:51+02:00 A confined–unconfined aquifer model for subglacial hydrology and its application to the Northeast Greenland Ice Stream S. Beyer T. Kleiner V. Aizinger M. Rückamp A. Humbert 2018-12-01 https://doi.org/10.5194/tc-12-3931-2018 https://www.the-cryosphere.net/12/3931/2018/tc-12-3931-2018.pdf https://doaj.org/article/0a4d7995c69648a78e56cbdb351e541e en eng Copernicus Publications doi:10.5194/tc-12-3931-2018 1994-0416 1994-0424 https://www.the-cryosphere.net/12/3931/2018/tc-12-3931-2018.pdf https://doaj.org/article/0a4d7995c69648a78e56cbdb351e541e undefined The Cryosphere, Vol 12, Pp 3931-3947 (2018) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2018 fttriple https://doi.org/10.5194/tc-12-3931-2018 2023-01-22T19:07:27Z Subglacial hydrology plays an important role in ice sheet dynamics as it determines the sliding velocity. It also drives freshwater into the ocean, leading to undercutting of calving fronts by plumes. Modeling subglacial water has been a challenge for decades. Only recently have new approaches been developed such as representing subglacial channels and thin water sheets by separate layers of variable hydraulic conductivity. We extend this concept by modeling a confined–unconfined aquifer system (CUAS) in a single layer of an equivalent porous medium (EPM). The advantage of this formulation is that it prevents unphysical values of pressure at reasonable computational cost. We performed sensitivity tests to investigate the effect of different model parameters. The strongest influence of model parameters was detected in terms of governing the opening and closure of the system. Furthermore, we applied the model to the Northeast Greenland Ice Stream, where an efficient system independent of seasonal input was identified about 500 km downstream from the ice divide. Using the effective pressure from the hydrology model, the Ice Sheet System Model (ISSM) showed considerable improvements in modeled velocities in the coastal region. Article in Journal/Newspaper Greenland Ice Sheet The Cryosphere Unknown Greenland The Cryosphere 12 12 3931 3947 |
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English |
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geo envir |
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geo envir S. Beyer T. Kleiner V. Aizinger M. Rückamp A. Humbert A confined–unconfined aquifer model for subglacial hydrology and its application to the Northeast Greenland Ice Stream |
topic_facet |
geo envir |
description |
Subglacial hydrology plays an important role in ice sheet dynamics as it determines the sliding velocity. It also drives freshwater into the ocean, leading to undercutting of calving fronts by plumes. Modeling subglacial water has been a challenge for decades. Only recently have new approaches been developed such as representing subglacial channels and thin water sheets by separate layers of variable hydraulic conductivity. We extend this concept by modeling a confined–unconfined aquifer system (CUAS) in a single layer of an equivalent porous medium (EPM). The advantage of this formulation is that it prevents unphysical values of pressure at reasonable computational cost. We performed sensitivity tests to investigate the effect of different model parameters. The strongest influence of model parameters was detected in terms of governing the opening and closure of the system. Furthermore, we applied the model to the Northeast Greenland Ice Stream, where an efficient system independent of seasonal input was identified about 500 km downstream from the ice divide. Using the effective pressure from the hydrology model, the Ice Sheet System Model (ISSM) showed considerable improvements in modeled velocities in the coastal region. |
format |
Article in Journal/Newspaper |
author |
S. Beyer T. Kleiner V. Aizinger M. Rückamp A. Humbert |
author_facet |
S. Beyer T. Kleiner V. Aizinger M. Rückamp A. Humbert |
author_sort |
S. Beyer |
title |
A confined–unconfined aquifer model for subglacial hydrology and its application to the Northeast Greenland Ice Stream |
title_short |
A confined–unconfined aquifer model for subglacial hydrology and its application to the Northeast Greenland Ice Stream |
title_full |
A confined–unconfined aquifer model for subglacial hydrology and its application to the Northeast Greenland Ice Stream |
title_fullStr |
A confined–unconfined aquifer model for subglacial hydrology and its application to the Northeast Greenland Ice Stream |
title_full_unstemmed |
A confined–unconfined aquifer model for subglacial hydrology and its application to the Northeast Greenland Ice Stream |
title_sort |
confined–unconfined aquifer model for subglacial hydrology and its application to the northeast greenland ice stream |
publisher |
Copernicus Publications |
publishDate |
2018 |
url |
https://doi.org/10.5194/tc-12-3931-2018 https://www.the-cryosphere.net/12/3931/2018/tc-12-3931-2018.pdf https://doaj.org/article/0a4d7995c69648a78e56cbdb351e541e |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Ice Sheet The Cryosphere |
genre_facet |
Greenland Ice Sheet The Cryosphere |
op_source |
The Cryosphere, Vol 12, Pp 3931-3947 (2018) |
op_relation |
doi:10.5194/tc-12-3931-2018 1994-0416 1994-0424 https://www.the-cryosphere.net/12/3931/2018/tc-12-3931-2018.pdf https://doaj.org/article/0a4d7995c69648a78e56cbdb351e541e |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-12-3931-2018 |
container_title |
The Cryosphere |
container_volume |
12 |
container_issue |
12 |
container_start_page |
3931 |
op_container_end_page |
3947 |
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1766017418690297856 |