Meltwater percolation, impermeable layer formation and runoff buffering on Devon Ice Cap, Canada
Abstract 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...
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Language: | English |
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Cambridge University Press (CUP)
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Online Access: | http://dx.doi.org/10.1017/jog.2019.80 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143019000807 |
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crcambridgeupr:10.1017/jog.2019.80 2024-09-15T18:09:54+00:00 Meltwater percolation, impermeable layer formation and runoff buffering on Devon Ice Cap, Canada Ashmore, David W. Mair, Douglas W. F. Burgess, David O. 2019 http://dx.doi.org/10.1017/jog.2019.80 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143019000807 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by/4.0/ Journal of Glaciology volume 66, issue 255, page 61-73 ISSN 0022-1430 1727-5652 journal-article 2019 crcambridgeupr https://doi.org/10.1017/jog.2019.80 2024-09-04T04:03:30Z Abstract 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. Article in Journal/Newspaper Greenland Ice cap Ice Sheet Journal of Glaciology Cambridge University Press Journal of Glaciology 66 255 61 73 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
Abstract 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. |
format |
Article in Journal/Newspaper |
author |
Ashmore, David W. Mair, Douglas W. F. Burgess, David O. |
spellingShingle |
Ashmore, David W. Mair, Douglas W. F. Burgess, David O. Meltwater percolation, impermeable layer formation and runoff buffering on Devon Ice Cap, Canada |
author_facet |
Ashmore, David W. Mair, Douglas W. F. Burgess, David O. |
author_sort |
Ashmore, David W. |
title |
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_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_sort |
meltwater percolation, impermeable layer formation and runoff buffering on devon ice cap, canada |
publisher |
Cambridge University Press (CUP) |
publishDate |
2019 |
url |
http://dx.doi.org/10.1017/jog.2019.80 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143019000807 |
genre |
Greenland Ice cap Ice Sheet Journal of Glaciology |
genre_facet |
Greenland Ice cap Ice Sheet Journal of Glaciology |
op_source |
Journal of Glaciology volume 66, issue 255, page 61-73 ISSN 0022-1430 1727-5652 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1017/jog.2019.80 |
container_title |
Journal of Glaciology |
container_volume |
66 |
container_issue |
255 |
container_start_page |
61 |
op_container_end_page |
73 |
_version_ |
1810447499697061888 |