Modelling lateral meltwater flow and superimposed ice formation atop Greenland's near-surface ice slabs
At high elevations on the Greenland ice sheet meltwater percolates and refreezes in place, and hence does not contribute to mass loss. However, meltwater generation and associated surface runoff is occurring from increasingly higher altitudes, causing changes in firn stratigraphy that have led to th...
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| 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/S0022143024000698/type/journal_article |
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| author | Nicole Clerx Horst Machguth Andrew Tedstone Dirk van As |
| author_facet | Nicole Clerx Horst Machguth Andrew Tedstone Dirk van As |
| author_sort | Nicole Clerx |
| collection | DOAJ |
| description | At high elevations on the Greenland ice sheet meltwater percolates and refreezes in place, and hence does not contribute to mass loss. However, meltwater generation and associated surface runoff is occurring from increasingly higher altitudes, causing changes in firn stratigraphy that have led to the presence of near-surface ice slabs. These ice slabs force meltwater to flow laterally instead of percolating downwards. Here we present a simple, physics-based quasi-2-D model to simulate lateral meltwater runoff and superimposed ice (SI) formation on top of ice slabs. Using an Eulerian Darcy flow scheme, the model calculates how far meltwater can travel within a melt season and when it appears at the snow surface. Results show that lateral flow is a highly efficient runoff mechanism, as lateral outflow exceeds locally generated meltwater in all model gridcells, with total meltwater discharge sometimes reaching more than 30 times the average amount of in situ generated melt. SI formation, an important process in the formation and thickening of the ice slabs, can retain up to 40% of the available meltwater, and generally delays the appearance of visible runoff. Validating the model against field- or remote-sensing data remains challenging, but the results presented here are a first step towards a more comprehensive understanding and description of the hydrological system in the accumulation zone of the southwestern Greenland ice sheet. |
| format | Article |
| id | doaj-art-fa09fd48985045b9a38ac182c0805865 |
| 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-fa09fd48985045b9a38ac182c08058652025-01-16T21:48:11ZengCambridge University PressJournal of Glaciology0022-14301727-56522024-01-017010.1017/jog.2024.69Modelling lateral meltwater flow and superimposed ice formation atop Greenland's near-surface ice slabsNicole Clerx0https://orcid.org/0000-0001-9089-6995Horst Machguth1https://orcid.org/0000-0001-5924-0998Andrew Tedstone2https://orcid.org/0000-0002-9211-451XDirk van As3Department of Geoscience, University of Fribourg, Fribourg, SwitzerlandDepartment of Geoscience, University of Fribourg, Fribourg, SwitzerlandDepartment of Geoscience, University of Fribourg, Fribourg, SwitzerlandGeological Survey of Denmark and Greenland (GEUS), Copenhagen, DenmarkAt high elevations on the Greenland ice sheet meltwater percolates and refreezes in place, and hence does not contribute to mass loss. However, meltwater generation and associated surface runoff is occurring from increasingly higher altitudes, causing changes in firn stratigraphy that have led to the presence of near-surface ice slabs. These ice slabs force meltwater to flow laterally instead of percolating downwards. Here we present a simple, physics-based quasi-2-D model to simulate lateral meltwater runoff and superimposed ice (SI) formation on top of ice slabs. Using an Eulerian Darcy flow scheme, the model calculates how far meltwater can travel within a melt season and when it appears at the snow surface. Results show that lateral flow is a highly efficient runoff mechanism, as lateral outflow exceeds locally generated meltwater in all model gridcells, with total meltwater discharge sometimes reaching more than 30 times the average amount of in situ generated melt. SI formation, an important process in the formation and thickening of the ice slabs, can retain up to 40% of the available meltwater, and generally delays the appearance of visible runoff. Validating the model against field- or remote-sensing data remains challenging, but the results presented here are a first step towards a more comprehensive understanding and description of the hydrological system in the accumulation zone of the southwestern Greenland ice sheet.https://www.cambridge.org/core/product/identifier/S0022143024000698/type/journal_articleglacier hydrologyglaciological model experimentsicesheet mass balancemelt – surfacesnow/ice surface processes |
| spellingShingle | Nicole Clerx Horst Machguth Andrew Tedstone Dirk van As Modelling lateral meltwater flow and superimposed ice formation atop Greenland's near-surface ice slabs Journal of Glaciology glacier hydrology glaciological model experiments icesheet mass balance melt – surface snow/ice surface processes |
| title | Modelling lateral meltwater flow and superimposed ice formation atop Greenland's near-surface ice slabs |
| title_full | Modelling lateral meltwater flow and superimposed ice formation atop Greenland's near-surface ice slabs |
| title_fullStr | Modelling lateral meltwater flow and superimposed ice formation atop Greenland's near-surface ice slabs |
| title_full_unstemmed | Modelling lateral meltwater flow and superimposed ice formation atop Greenland's near-surface ice slabs |
| title_short | Modelling lateral meltwater flow and superimposed ice formation atop Greenland's near-surface ice slabs |
| title_sort | modelling lateral meltwater flow and superimposed ice formation atop greenland s near surface ice slabs |
| topic | glacier hydrology glaciological model experiments icesheet mass balance melt – surface snow/ice surface processes |
| url | https://www.cambridge.org/core/product/identifier/S0022143024000698/type/journal_article |
| work_keys_str_mv | AT nicoleclerx modellinglateralmeltwaterflowandsuperimposediceformationatopgreenlandsnearsurfaceiceslabs AT horstmachguth modellinglateralmeltwaterflowandsuperimposediceformationatopgreenlandsnearsurfaceiceslabs AT andrewtedstone modellinglateralmeltwaterflowandsuperimposediceformationatopgreenlandsnearsurfaceiceslabs AT dirkvanas modellinglateralmeltwaterflowandsuperimposediceformationatopgreenlandsnearsurfaceiceslabs |