Improved representation of laminar and turbulent sheet flow in subglacial drainage models
Subglacial hydrology models struggle to reproduce seasonal drainage patterns that are consistent with observed subglacial water pressures and surface velocities. We modify the standard sheet-flow parameterization within a coupled sheet–channel subglacial drainage model to smoothly transition between...
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| Format: | Article |
| Language: | English |
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Cambridge University Press
2024-01-01
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| Series: | Journal of Glaciology |
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| Online Access: | https://www.cambridge.org/core/product/identifier/S002214302300103X/type/journal_article |
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| _version_ | 1841526394948943872 |
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| author | Tim Hill Gwenn Elizabeth Flowers Matthew James Hoffman Derek Bingham Mauro Angelo Werder |
| author_facet | Tim Hill Gwenn Elizabeth Flowers Matthew James Hoffman Derek Bingham Mauro Angelo Werder |
| author_sort | Tim Hill |
| collection | DOAJ |
| description | Subglacial hydrology models struggle to reproduce seasonal drainage patterns that are consistent with observed subglacial water pressures and surface velocities. We modify the standard sheet-flow parameterization within a coupled sheet–channel subglacial drainage model to smoothly transition between laminar and turbulent flow based on the locally computed Reynolds number in a physically consistent way (the ‘transition’ model). We compare the transition model to standard laminar and turbulent models to assess the role of the sheet-flow parameterization in reconciling observed and modelled water pressures under idealized and realistic forcing. Relative to the turbulent model, the laminar and transition models improve seasonal simulations by increasing winter water pressure and producing a more prominent late-summer water pressure minimum. In contrast to the laminar model, the transition model remains consistent with its own internal assumptions across all flow regimes. Based on the internal consistency of the transition model and its improved performance relative to the standard turbulent model, we recommend its use for transient simulations of subglacial drainage. |
| format | Article |
| id | doaj-art-011cf0ceb9bb441f8279ac8be948319b |
| institution | Kabale University |
| issn | 0022-1430 1727-5652 |
| language | English |
| publishDate | 2024-01-01 |
| publisher | Cambridge University Press |
| record_format | Article |
| series | Journal of Glaciology |
| spelling | doaj-art-011cf0ceb9bb441f8279ac8be948319b2025-01-16T21:52:53ZengCambridge University PressJournal of Glaciology0022-14301727-56522024-01-017010.1017/jog.2023.103Improved representation of laminar and turbulent sheet flow in subglacial drainage modelsTim Hill0https://orcid.org/0000-0002-3538-7060Gwenn Elizabeth Flowers1https://orcid.org/0000-0002-3574-9324Matthew James Hoffman2https://orcid.org/0000-0001-5076-0540Derek Bingham3Mauro Angelo Werder4https://orcid.org/0000-0003-0137-9377Department of Earth Sciences, Simon Fraser University, Burnaby, BC, CanadaDepartment of Earth Sciences, Simon Fraser University, Burnaby, BC, CanadaFluid Dynamics and Solid Mechanics Group, Los Alamos National Laboratory, Los Alamos, NM, USADepartment of Statistics and Actuarial Science, Simon Fraser University, Burnaby, BC, CanadaLaboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zurich, Zurich, Switzerland Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, SwitzerlandSubglacial hydrology models struggle to reproduce seasonal drainage patterns that are consistent with observed subglacial water pressures and surface velocities. We modify the standard sheet-flow parameterization within a coupled sheet–channel subglacial drainage model to smoothly transition between laminar and turbulent flow based on the locally computed Reynolds number in a physically consistent way (the ‘transition’ model). We compare the transition model to standard laminar and turbulent models to assess the role of the sheet-flow parameterization in reconciling observed and modelled water pressures under idealized and realistic forcing. Relative to the turbulent model, the laminar and transition models improve seasonal simulations by increasing winter water pressure and producing a more prominent late-summer water pressure minimum. In contrast to the laminar model, the transition model remains consistent with its own internal assumptions across all flow regimes. Based on the internal consistency of the transition model and its improved performance relative to the standard turbulent model, we recommend its use for transient simulations of subglacial drainage.https://www.cambridge.org/core/product/identifier/S002214302300103X/type/journal_articleGlacier hydrologyglacier modellingsubglacial processes |
| spellingShingle | Tim Hill Gwenn Elizabeth Flowers Matthew James Hoffman Derek Bingham Mauro Angelo Werder Improved representation of laminar and turbulent sheet flow in subglacial drainage models Journal of Glaciology Glacier hydrology glacier modelling subglacial processes |
| title | Improved representation of laminar and turbulent sheet flow in subglacial drainage models |
| title_full | Improved representation of laminar and turbulent sheet flow in subglacial drainage models |
| title_fullStr | Improved representation of laminar and turbulent sheet flow in subglacial drainage models |
| title_full_unstemmed | Improved representation of laminar and turbulent sheet flow in subglacial drainage models |
| title_short | Improved representation of laminar and turbulent sheet flow in subglacial drainage models |
| title_sort | improved representation of laminar and turbulent sheet flow in subglacial drainage models |
| topic | Glacier hydrology glacier modelling subglacial processes |
| url | https://www.cambridge.org/core/product/identifier/S002214302300103X/type/journal_article |
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