Basal conditions of Denman Glacier from glacier hydrology and ice dynamics modeling
Basal sliding in Antarctic glaciers is often modeled using a friction law that relates basal shear stresses to the effective pressure. As few ice sheet models are dynamically coupled to subglacial hydrology models, variability in subglacial hydrology associated with the effective pressure is often i...
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ftdoajarticles:oai:doaj.org/article:2996b5504863451e8b11884effe651c2 2023-12-10T09:43:01+01:00 Basal conditions of Denman Glacier from glacier hydrology and ice dynamics modeling K. McArthur F. S. McCormack C. F. Dow 2023-11-01T00:00:00Z https://doi.org/10.5194/tc-17-4705-2023 https://doaj.org/article/2996b5504863451e8b11884effe651c2 EN eng Copernicus Publications https://tc.copernicus.org/articles/17/4705/2023/tc-17-4705-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-4705-2023 1994-0416 1994-0424 https://doaj.org/article/2996b5504863451e8b11884effe651c2 The Cryosphere, Vol 17, Pp 4705-4727 (2023) Environmental sciences GE1-350 Geology QE1-996.5 article 2023 ftdoajarticles https://doi.org/10.5194/tc-17-4705-2023 2023-11-12T01:37:53Z Basal sliding in Antarctic glaciers is often modeled using a friction law that relates basal shear stresses to the effective pressure. As few ice sheet models are dynamically coupled to subglacial hydrology models, variability in subglacial hydrology associated with the effective pressure is often implicitly captured in the basal friction coefficient – an unknown parameter in the basal friction law. We investigate the impact of using effective pressures calculated from the Glacier Drainage System (GlaDS) model on basal friction coefficients calculated using inverse methods in the Ice-sheet and Sea-level System Model (ISSM) at Denman Glacier, East Antarctica, for the Schoof and Budd friction laws. For the Schoof friction law, a positive correlation emerges between the GlaDS effective pressure and basal friction coefficient in regions of fast ice flow. Using GlaDS effective pressures generally leads to smoother basal friction coefficients and basal shear stresses, and larger differences between the simulated and observed ice surface velocities compared with using an effective pressure equal to the ice overburden pressure plus the gravitational potential energy of the water. Compared with the Budd friction law, the Schoof friction law offers improved capabilities in capturing the spatial variations associated with known physics of the subglacial hydrology. Our results indicate that ice sheet model representation of basal sliding is more realistic when using direct outputs from a subglacial hydrology model, demonstrating the importance of coupling between ice sheet and subglacial hydrological systems. However, using our outputs we have also developed an empirical parameterization of effective pressure that improves the application of the Schoof friction law without requiring explicit hydrological modeling. Article in Journal/Newspaper Antarc* Antarctic Antarctica Denman Glacier East Antarctica Ice Sheet The Cryosphere Directory of Open Access Journals: DOAJ Articles Antarctic East Antarctica Denman Glacier ENVELOPE(99.417,99.417,-66.750,-66.750) The Cryosphere 17 11 4705 4727 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 K. McArthur F. S. McCormack C. F. Dow Basal conditions of Denman Glacier from glacier hydrology and ice dynamics modeling |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Basal sliding in Antarctic glaciers is often modeled using a friction law that relates basal shear stresses to the effective pressure. As few ice sheet models are dynamically coupled to subglacial hydrology models, variability in subglacial hydrology associated with the effective pressure is often implicitly captured in the basal friction coefficient – an unknown parameter in the basal friction law. We investigate the impact of using effective pressures calculated from the Glacier Drainage System (GlaDS) model on basal friction coefficients calculated using inverse methods in the Ice-sheet and Sea-level System Model (ISSM) at Denman Glacier, East Antarctica, for the Schoof and Budd friction laws. For the Schoof friction law, a positive correlation emerges between the GlaDS effective pressure and basal friction coefficient in regions of fast ice flow. Using GlaDS effective pressures generally leads to smoother basal friction coefficients and basal shear stresses, and larger differences between the simulated and observed ice surface velocities compared with using an effective pressure equal to the ice overburden pressure plus the gravitational potential energy of the water. Compared with the Budd friction law, the Schoof friction law offers improved capabilities in capturing the spatial variations associated with known physics of the subglacial hydrology. Our results indicate that ice sheet model representation of basal sliding is more realistic when using direct outputs from a subglacial hydrology model, demonstrating the importance of coupling between ice sheet and subglacial hydrological systems. However, using our outputs we have also developed an empirical parameterization of effective pressure that improves the application of the Schoof friction law without requiring explicit hydrological modeling. |
format |
Article in Journal/Newspaper |
author |
K. McArthur F. S. McCormack C. F. Dow |
author_facet |
K. McArthur F. S. McCormack C. F. Dow |
author_sort |
K. McArthur |
title |
Basal conditions of Denman Glacier from glacier hydrology and ice dynamics modeling |
title_short |
Basal conditions of Denman Glacier from glacier hydrology and ice dynamics modeling |
title_full |
Basal conditions of Denman Glacier from glacier hydrology and ice dynamics modeling |
title_fullStr |
Basal conditions of Denman Glacier from glacier hydrology and ice dynamics modeling |
title_full_unstemmed |
Basal conditions of Denman Glacier from glacier hydrology and ice dynamics modeling |
title_sort |
basal conditions of denman glacier from glacier hydrology and ice dynamics modeling |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/tc-17-4705-2023 https://doaj.org/article/2996b5504863451e8b11884effe651c2 |
long_lat |
ENVELOPE(99.417,99.417,-66.750,-66.750) |
geographic |
Antarctic East Antarctica Denman Glacier |
geographic_facet |
Antarctic East Antarctica Denman Glacier |
genre |
Antarc* Antarctic Antarctica Denman Glacier East Antarctica Ice Sheet The Cryosphere |
genre_facet |
Antarc* Antarctic Antarctica Denman Glacier East Antarctica Ice Sheet The Cryosphere |
op_source |
The Cryosphere, Vol 17, Pp 4705-4727 (2023) |
op_relation |
https://tc.copernicus.org/articles/17/4705/2023/tc-17-4705-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-4705-2023 1994-0416 1994-0424 https://doaj.org/article/2996b5504863451e8b11884effe651c2 |
op_doi |
https://doi.org/10.5194/tc-17-4705-2023 |
container_title |
The Cryosphere |
container_volume |
17 |
container_issue |
11 |
container_start_page |
4705 |
op_container_end_page |
4727 |
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1784886147369926656 |