Seasonal monitoring of melt and accumulation within the deep percolation zone of the Greenland Ice Sheet and comparison with simulations of regional climate modeling
peer reviewed Increasing melt over the Greenland Ice Sheet (GrIS) recorded over the past several years has resulted in significant changes of the percolation regime of the ice sheet. It remains unclear whether Greenland's percolation zone will act as a meltwater buffer in the near future throug...
Published in: | The Cryosphere |
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Format: | Article in Journal/Newspaper |
Language: | English |
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Copernicus Group
2018
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Online Access: | https://orbi.uliege.be/handle/2268/224285 https://orbi.uliege.be/bitstream/2268/224285/1/tc-12-1851-2018.pdf https://doi.org/10.5194/tc-12-1851-2018 |
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ftorbi:oai:orbi.ulg.ac.be:2268/224285 2024-04-21T08:03:45+00:00 Seasonal monitoring of melt and accumulation within the deep percolation zone of the Greenland Ice Sheet and comparison with simulations of regional climate modeling Heilig, Achim Eisen, O. MacFerrin, Michael Tedesco, M. Fettweis, Xavier 2018-06-04 https://orbi.uliege.be/handle/2268/224285 https://orbi.uliege.be/bitstream/2268/224285/1/tc-12-1851-2018.pdf https://doi.org/10.5194/tc-12-1851-2018 en eng Copernicus Group https://www.the-cryosphere.net/12/1851/2018/ urn:issn:1994-0416 urn:issn:1994-0424 https://orbi.uliege.be/handle/2268/224285 info:hdl:2268/224285 https://orbi.uliege.be/bitstream/2268/224285/1/tc-12-1851-2018.pdf doi:10.5194/tc-12-1851-2018 scopus-id:2-s2.0-85048083122 open access http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess The Cryosphere, 12, 1851-1866 (2018-06-04) Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique journal article http://purl.org/coar/resource_type/c_6501 info:eu-repo/semantics/article peer reviewed 2018 ftorbi https://doi.org/10.5194/tc-12-1851-2018 2024-03-27T14:58:15Z peer reviewed Increasing melt over the Greenland Ice Sheet (GrIS) recorded over the past several years has resulted in significant changes of the percolation regime of the ice sheet. It remains unclear whether Greenland's percolation zone will act as a meltwater buffer in the near future through gradually filling all pore space or if near-surface refreezing causes the formation of impermeable layers, which provoke lateral runoff. Homogeneous ice layers within perennial firn, as well as near-surface ice layers of several meter thickness have been observed in firn cores. Because firn coring is a destructive method, deriving stratigraphic changes in firn and allocation of summer melt events is challenging. To overcome this deficit and provide continuous data for model evaluations on snow and firn density, temporal changes in liquid water content and depths of water infiltration, we installed an upward-looking radar system (upGPR) 3.4 m below the snow surface in May 2016 close to Camp Raven (66.4779° N, 46.2856° W) at 2120 m a.s.l. The radar is capable of quasi-continuously monitoring changes in snow and firn stratigraphy, which occur above the antennas. For summer 2016, we observed four major melt events, which routed liquid water into various depths beneath the surface. The last event in mid-August resulted in the deepest percolation down to about 2.3 m beneath the surface. Comparisons with simulations from the regional climate model MAR are in very good agreement in terms of seasonal changes in accumulation and timing of onset of melt. However, neither bulk density of near-surface layers nor the amounts of liquid water and percolation depths predicted by MAR correspond with upGPR data. Radar data and records of a nearby thermistor string, in contrast, matched very well for both timing and depth of temperature changes and observed water percolations. All four melt events transferred a cumulative mass of 56 kg m−2 into firn beneath the summer surface of 2015. We find that continuous observations of liquid water ... Article in Journal/Newspaper Greenland Ice Sheet The Cryosphere University of Liège: ORBi (Open Repository and Bibliography) The Cryosphere 12 6 1851 1866 |
institution |
Open Polar |
collection |
University of Liège: ORBi (Open Repository and Bibliography) |
op_collection_id |
ftorbi |
language |
English |
topic |
Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique |
spellingShingle |
Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique Heilig, Achim Eisen, O. MacFerrin, Michael Tedesco, M. Fettweis, Xavier Seasonal monitoring of melt and accumulation within the deep percolation zone of the Greenland Ice Sheet and comparison with simulations of regional climate modeling |
topic_facet |
Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique |
description |
peer reviewed Increasing melt over the Greenland Ice Sheet (GrIS) recorded over the past several years has resulted in significant changes of the percolation regime of the ice sheet. It remains unclear whether Greenland's percolation zone will act as a meltwater buffer in the near future through gradually filling all pore space or if near-surface refreezing causes the formation of impermeable layers, which provoke lateral runoff. Homogeneous ice layers within perennial firn, as well as near-surface ice layers of several meter thickness have been observed in firn cores. Because firn coring is a destructive method, deriving stratigraphic changes in firn and allocation of summer melt events is challenging. To overcome this deficit and provide continuous data for model evaluations on snow and firn density, temporal changes in liquid water content and depths of water infiltration, we installed an upward-looking radar system (upGPR) 3.4 m below the snow surface in May 2016 close to Camp Raven (66.4779° N, 46.2856° W) at 2120 m a.s.l. The radar is capable of quasi-continuously monitoring changes in snow and firn stratigraphy, which occur above the antennas. For summer 2016, we observed four major melt events, which routed liquid water into various depths beneath the surface. The last event in mid-August resulted in the deepest percolation down to about 2.3 m beneath the surface. Comparisons with simulations from the regional climate model MAR are in very good agreement in terms of seasonal changes in accumulation and timing of onset of melt. However, neither bulk density of near-surface layers nor the amounts of liquid water and percolation depths predicted by MAR correspond with upGPR data. Radar data and records of a nearby thermistor string, in contrast, matched very well for both timing and depth of temperature changes and observed water percolations. All four melt events transferred a cumulative mass of 56 kg m−2 into firn beneath the summer surface of 2015. We find that continuous observations of liquid water ... |
format |
Article in Journal/Newspaper |
author |
Heilig, Achim Eisen, O. MacFerrin, Michael Tedesco, M. Fettweis, Xavier |
author_facet |
Heilig, Achim Eisen, O. MacFerrin, Michael Tedesco, M. Fettweis, Xavier |
author_sort |
Heilig, Achim |
title |
Seasonal monitoring of melt and accumulation within the deep percolation zone of the Greenland Ice Sheet and comparison with simulations of regional climate modeling |
title_short |
Seasonal monitoring of melt and accumulation within the deep percolation zone of the Greenland Ice Sheet and comparison with simulations of regional climate modeling |
title_full |
Seasonal monitoring of melt and accumulation within the deep percolation zone of the Greenland Ice Sheet and comparison with simulations of regional climate modeling |
title_fullStr |
Seasonal monitoring of melt and accumulation within the deep percolation zone of the Greenland Ice Sheet and comparison with simulations of regional climate modeling |
title_full_unstemmed |
Seasonal monitoring of melt and accumulation within the deep percolation zone of the Greenland Ice Sheet and comparison with simulations of regional climate modeling |
title_sort |
seasonal monitoring of melt and accumulation within the deep percolation zone of the greenland ice sheet and comparison with simulations of regional climate modeling |
publisher |
Copernicus Group |
publishDate |
2018 |
url |
https://orbi.uliege.be/handle/2268/224285 https://orbi.uliege.be/bitstream/2268/224285/1/tc-12-1851-2018.pdf https://doi.org/10.5194/tc-12-1851-2018 |
genre |
Greenland Ice Sheet The Cryosphere |
genre_facet |
Greenland Ice Sheet The Cryosphere |
op_source |
The Cryosphere, 12, 1851-1866 (2018-06-04) |
op_relation |
https://www.the-cryosphere.net/12/1851/2018/ urn:issn:1994-0416 urn:issn:1994-0424 https://orbi.uliege.be/handle/2268/224285 info:hdl:2268/224285 https://orbi.uliege.be/bitstream/2268/224285/1/tc-12-1851-2018.pdf doi:10.5194/tc-12-1851-2018 scopus-id:2-s2.0-85048083122 |
op_rights |
open access http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/tc-12-1851-2018 |
container_title |
The Cryosphere |
container_volume |
12 |
container_issue |
6 |
container_start_page |
1851 |
op_container_end_page |
1866 |
_version_ |
1796943477718646784 |