Meltwater percolation, impermeable layer formation and runoff buffering on Devon Ice Cap, Canada
The retention of meltwater in the accumulation area of the Greenland ice sheet and other Arctic ice masses buffers their contribution to sea level change. However, sustained warming also results in impermeable ice layers or ‘ice slabs’ that seal the underlying pore space. Here, we use a 1-D, physica...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Cambridge University Press
2020-02-01
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| Series: | Journal of Glaciology |
| Subjects: | |
| Online Access: | https://www.cambridge.org/core/product/identifier/S0022143019000807/type/journal_article |
| _version_ | 1811155777650425856 |
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| author | David W. Ashmore Douglas W. F. Mair David O. Burgess |
| author_facet | David W. Ashmore Douglas W. F. Mair David O. Burgess |
| author_sort | David W. Ashmore |
| collection | DOAJ |
| description | The retention of meltwater in the accumulation area of the Greenland ice sheet and other Arctic ice masses buffers their contribution to sea level change. However, sustained warming also results in impermeable ice layers or ‘ice slabs’ that seal the underlying pore space. Here, we use a 1-D, physically based, high-resolution model to simulate the surface mass balance (SMB), percolation, refreezing, ice layer formation and runoff from across the high-elevation area of Devon Ice Cap, Canada, from 2001 to 2016. We vary the thickness of the ‘impermeable’ ice layer at which underlying firn becomes inaccessible to meltwater. Thick near-surface ice layers are established by an initial deep percolation, the formation of decimetre ice layers and the infilling of interleaving pore space. The cumulative SMB increases by 48% by varying impermeable layer thickness between 0.01 and 5 m. Within this range we identify narrower range (0.25–1 m) that can simulate both the temporal variability in SMB and the observed near-surface density structure. Across this range, cumulative SMB variation is limited to 6% and 45–49% of mass retention takes place within the annually replenished snowpack. Our results indicate cooler summers after intense mid-2000s warming have led to a partial replenishment of pore space. |
| first_indexed | 2024-04-10T04:40:20Z |
| format | Article |
| id | doaj.art-08d5a37c5d3b43198216d81c649242fb |
| institution | Directory Open Access Journal |
| issn | 0022-1430 1727-5652 |
| language | English |
| last_indexed | 2024-04-10T04:40:20Z |
| publishDate | 2020-02-01 |
| publisher | Cambridge University Press |
| record_format | Article |
| series | Journal of Glaciology |
| spelling | doaj.art-08d5a37c5d3b43198216d81c649242fb2023-03-09T12:40:51ZengCambridge University PressJournal of Glaciology0022-14301727-56522020-02-0166617310.1017/jog.2019.80Meltwater percolation, impermeable layer formation and runoff buffering on Devon Ice Cap, CanadaDavid W. Ashmore0Douglas W. F. Mair1David O. Burgess2School of Environmental Sciences, Roxby Building, University of Liverpool, LiverpoolL69 7ZT, UKSchool of Environmental Sciences, Roxby Building, University of Liverpool, LiverpoolL69 7ZT, UKNatural Resources Canada, 601 Booth St., Ottawa, OntarioK1A 0E8, CanadaThe retention of meltwater in the accumulation area of the Greenland ice sheet and other Arctic ice masses buffers their contribution to sea level change. However, sustained warming also results in impermeable ice layers or ‘ice slabs’ that seal the underlying pore space. Here, we use a 1-D, physically based, high-resolution model to simulate the surface mass balance (SMB), percolation, refreezing, ice layer formation and runoff from across the high-elevation area of Devon Ice Cap, Canada, from 2001 to 2016. We vary the thickness of the ‘impermeable’ ice layer at which underlying firn becomes inaccessible to meltwater. Thick near-surface ice layers are established by an initial deep percolation, the formation of decimetre ice layers and the infilling of interleaving pore space. The cumulative SMB increases by 48% by varying impermeable layer thickness between 0.01 and 5 m. Within this range we identify narrower range (0.25–1 m) that can simulate both the temporal variability in SMB and the observed near-surface density structure. Across this range, cumulative SMB variation is limited to 6% and 45–49% of mass retention takes place within the annually replenished snowpack. Our results indicate cooler summers after intense mid-2000s warming have led to a partial replenishment of pore space.https://www.cambridge.org/core/product/identifier/S0022143019000807/type/journal_articleArctic glaciologymelt – surfacepolar firnsnow/ice surface processessurface mass budget |
| spellingShingle | David W. Ashmore Douglas W. F. Mair David O. Burgess Meltwater percolation, impermeable layer formation and runoff buffering on Devon Ice Cap, Canada Journal of Glaciology Arctic glaciology melt – surface polar firn snow/ice surface processes surface mass budget |
| title | Meltwater percolation, impermeable layer formation and runoff buffering on Devon Ice Cap, Canada |
| title_full | Meltwater percolation, impermeable layer formation and runoff buffering on Devon Ice Cap, Canada |
| title_fullStr | Meltwater percolation, impermeable layer formation and runoff buffering on Devon Ice Cap, Canada |
| title_full_unstemmed | Meltwater percolation, impermeable layer formation and runoff buffering on Devon Ice Cap, Canada |
| title_short | Meltwater percolation, impermeable layer formation and runoff buffering on Devon Ice Cap, Canada |
| title_sort | meltwater percolation impermeable layer formation and runoff buffering on devon ice cap canada |
| topic | Arctic glaciology melt – surface polar firn snow/ice surface processes surface mass budget |
| url | https://www.cambridge.org/core/product/identifier/S0022143019000807/type/journal_article |
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