Development of physically based liquid water schemes for Greenland firn-densification models
peer reviewed As surface melt is increasing on the Greenland Ice Sheet (GrIS), quantifying the retention capacity of the firn layer is critical to linking meltwater production to meltwater runoff. Firn-densification models have so far relied on empirical approaches to account for the percolation-ref...
Published in: | The Cryosphere |
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Language: | English |
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Copernicus GmbH
2019
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Online Access: | https://orbi.uliege.be/handle/2268/301928 https://orbi.uliege.be/bitstream/2268/301928/1/Verjans_TC_2019.pdf https://doi.org/10.5194/tc-13-1819-2019 |
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ftorbi:oai:orbi.ulg.ac.be:2268/301928 2024-04-21T08:03:45+00:00 Development of physically based liquid water schemes for Greenland firn-densification models Verjans, Vincent Leeson, Amber A. Max Stevens, C. MacFerrin, Michael Noël, Brice Van Den Broeke, Michiel R. 2019-07-09 https://orbi.uliege.be/handle/2268/301928 https://orbi.uliege.be/bitstream/2268/301928/1/Verjans_TC_2019.pdf https://doi.org/10.5194/tc-13-1819-2019 en eng Copernicus GmbH https://tc.copernicus.org/articles/13/1819/2019/tc-13-1819-2019.pdf urn:issn:1994-0416 urn:issn:1994-0424 https://orbi.uliege.be/handle/2268/301928 info:hdl:2268/301928 https://orbi.uliege.be/bitstream/2268/301928/1/Verjans_TC_2019.pdf doi:10.5194/tc-13-1819-2019 scopus-id:2-s2.0-85068880084 open access http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess The Cryosphere, 13 (7), 1819 - 1842 (2019-07-09) Water Science and Technology Earth-Surface Processes 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 2019 ftorbi https://doi.org/10.5194/tc-13-1819-2019 2024-03-27T14:58:15Z peer reviewed As surface melt is increasing on the Greenland Ice Sheet (GrIS), quantifying the retention capacity of the firn layer is critical to linking meltwater production to meltwater runoff. Firn-densification models have so far relied on empirical approaches to account for the percolation-refreezing process, and more physically based representations of liquid water flow might bring improvements to model performance. Here we implement three types of water percolation schemes into the Community Firn Model: the bucket approach, the Richards equation in a single domain and the Richards equation in a dual domain, which accounts for partitioning between matrix and fast preferential flow. We investigate their impact on firn densification at four locations on the GrIS and compare model results with observations. We find that for all of the flow schemes, significant discrepancies remain with respect to observed firn density, particularly the density variability in depth, and that inter-model differences are large (porosity of the upper 15m firn varies by up to 47%). The simple bucket scheme is as efficient in replicating observed density profiles as the single-domain Richards equation, and the most physically detailed dual-domain scheme does not necessarily reach best agreement with observed data. However, we find that the implementation of preferential flow simulates ice-layer formation more reliably and allows for deeper percolation. We also find that the firn model is more sensitive to the choice of densification scheme than to the choice of water percolation scheme. The disagreements with observations and the spread in model results demonstrate that progress towards an accurate description of water flow in firn is necessary. The numerous uncertainties about firn structure (e.g. grain size and shape, presence of ice layers) and about its hydraulic properties, as well as the one-dimensionality of firn models, render the implementation of physically based percolation schemes difficult. Additionally, the ... Article in Journal/Newspaper Greenland Ice Sheet The Cryosphere University of Liège: ORBi (Open Repository and Bibliography) The Cryosphere 13 7 1819 1842 |
institution |
Open Polar |
collection |
University of Liège: ORBi (Open Repository and Bibliography) |
op_collection_id |
ftorbi |
language |
English |
topic |
Water Science and Technology Earth-Surface Processes Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique |
spellingShingle |
Water Science and Technology Earth-Surface Processes Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique Verjans, Vincent Leeson, Amber A. Max Stevens, C. MacFerrin, Michael Noël, Brice Van Den Broeke, Michiel R. Development of physically based liquid water schemes for Greenland firn-densification models |
topic_facet |
Water Science and Technology Earth-Surface Processes 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 As surface melt is increasing on the Greenland Ice Sheet (GrIS), quantifying the retention capacity of the firn layer is critical to linking meltwater production to meltwater runoff. Firn-densification models have so far relied on empirical approaches to account for the percolation-refreezing process, and more physically based representations of liquid water flow might bring improvements to model performance. Here we implement three types of water percolation schemes into the Community Firn Model: the bucket approach, the Richards equation in a single domain and the Richards equation in a dual domain, which accounts for partitioning between matrix and fast preferential flow. We investigate their impact on firn densification at four locations on the GrIS and compare model results with observations. We find that for all of the flow schemes, significant discrepancies remain with respect to observed firn density, particularly the density variability in depth, and that inter-model differences are large (porosity of the upper 15m firn varies by up to 47%). The simple bucket scheme is as efficient in replicating observed density profiles as the single-domain Richards equation, and the most physically detailed dual-domain scheme does not necessarily reach best agreement with observed data. However, we find that the implementation of preferential flow simulates ice-layer formation more reliably and allows for deeper percolation. We also find that the firn model is more sensitive to the choice of densification scheme than to the choice of water percolation scheme. The disagreements with observations and the spread in model results demonstrate that progress towards an accurate description of water flow in firn is necessary. The numerous uncertainties about firn structure (e.g. grain size and shape, presence of ice layers) and about its hydraulic properties, as well as the one-dimensionality of firn models, render the implementation of physically based percolation schemes difficult. Additionally, the ... |
format |
Article in Journal/Newspaper |
author |
Verjans, Vincent Leeson, Amber A. Max Stevens, C. MacFerrin, Michael Noël, Brice Van Den Broeke, Michiel R. |
author_facet |
Verjans, Vincent Leeson, Amber A. Max Stevens, C. MacFerrin, Michael Noël, Brice Van Den Broeke, Michiel R. |
author_sort |
Verjans, Vincent |
title |
Development of physically based liquid water schemes for Greenland firn-densification models |
title_short |
Development of physically based liquid water schemes for Greenland firn-densification models |
title_full |
Development of physically based liquid water schemes for Greenland firn-densification models |
title_fullStr |
Development of physically based liquid water schemes for Greenland firn-densification models |
title_full_unstemmed |
Development of physically based liquid water schemes for Greenland firn-densification models |
title_sort |
development of physically based liquid water schemes for greenland firn-densification models |
publisher |
Copernicus GmbH |
publishDate |
2019 |
url |
https://orbi.uliege.be/handle/2268/301928 https://orbi.uliege.be/bitstream/2268/301928/1/Verjans_TC_2019.pdf https://doi.org/10.5194/tc-13-1819-2019 |
genre |
Greenland Ice Sheet The Cryosphere |
genre_facet |
Greenland Ice Sheet The Cryosphere |
op_source |
The Cryosphere, 13 (7), 1819 - 1842 (2019-07-09) |
op_relation |
https://tc.copernicus.org/articles/13/1819/2019/tc-13-1819-2019.pdf urn:issn:1994-0416 urn:issn:1994-0424 https://orbi.uliege.be/handle/2268/301928 info:hdl:2268/301928 https://orbi.uliege.be/bitstream/2268/301928/1/Verjans_TC_2019.pdf doi:10.5194/tc-13-1819-2019 scopus-id:2-s2.0-85068880084 |
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-13-1819-2019 |
container_title |
The Cryosphere |
container_volume |
13 |
container_issue |
7 |
container_start_page |
1819 |
op_container_end_page |
1842 |
_version_ |
1796943484565848064 |