Strong Summer Atmospheric Rivers Trigger Greenland Ice Sheet Melt through Spatially Varying Surface Energy Balance and Cloud Regimes
peer reviewed Mass loss from the Greenland Ice Sheet (GrIS) has accelerated over the past two decades, coincident with rapid Arctic warming and increasing moisture transport over Greenland by atmospheric rivers (ARs). Summer ARs affect- ing western Greenland trigger GrIS melt events, but the physica...
Published in: | Journal of Climate |
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Format: | Article in Journal/Newspaper |
Language: | English |
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American Meteorological Society
2020
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Online Access: | https://orbi.uliege.be/handle/2268/248320 https://orbi.uliege.be/bitstream/2268/248320/1/jcli-d-19-0835.1.pdf https://doi.org/10.1175/JCLI-D-19-0835.1 |
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ftorbi:oai:orbi.ulg.ac.be:2268/248320 2024-04-21T08:02:53+00:00 Strong Summer Atmospheric Rivers Trigger Greenland Ice Sheet Melt through Spatially Varying Surface Energy Balance and Cloud Regimes Mattingly, K. Mote, T. Fettweis, Xavier van As, D. Van Tricht, K. Lhermitte, S. Pettersen, C. Fausto, R. Sphères - SPHERES 2020-06-09 https://orbi.uliege.be/handle/2268/248320 https://orbi.uliege.be/bitstream/2268/248320/1/jcli-d-19-0835.1.pdf https://doi.org/10.1175/JCLI-D-19-0835.1 en eng American Meteorological Society https://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-19-0835.1 urn:issn:0894-8755 urn:issn:1520-0442 https://orbi.uliege.be/handle/2268/248320 info:hdl:2268/248320 https://orbi.uliege.be/bitstream/2268/248320/1/jcli-d-19-0835.1.pdf doi:10.1175/JCLI-D-19-0835.1 scopus-id:2-s2.0-85086476063 open access http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess Journal of Climate (2020-06-09) 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 2020 ftorbi https://doi.org/10.1175/JCLI-D-19-0835.1 2024-03-27T14:54:15Z peer reviewed Mass loss from the Greenland Ice Sheet (GrIS) has accelerated over the past two decades, coincident with rapid Arctic warming and increasing moisture transport over Greenland by atmospheric rivers (ARs). Summer ARs affect- ing western Greenland trigger GrIS melt events, but the physical mechanisms through which ARs induce melt are not well understood. This study elu- cidates the coupled surface-atmosphere processes by which ARs force GrIS melt through analysis of the surface energy balance (SEB), cloud properties, and local- to synoptic-scale atmospheric conditions during strong summer AR events affecting western Greenland. ARs are identified in MERRA-2 reanal- ysis (1980–2017) and classified by integrated water vapor transport (IVT) intensity. SEB, cloud, and atmospheric data from regional climate model, observational, reanalysis, and satellite-based datasets are used to analyze melt-inducing physical processes during strong, > 90th percentile “AR90+ ” events. Near AR “landfall”, AR90+ days feature increased cloud cover that re- duces net shortwave radiation and increases net longwave radiation. As these oppositely-signed radiative anomalies partly cancel during AR90+ events, in- creased melt energy in the ablation zone is primarily provided by turbulent heat fluxes, particularly sensible heat flux. These turbulent heat fluxes are driven by enhanced barrier winds generated by a stronger synoptic pressure gradient combined with an enhanced local temperature contrast between cool over-ice air and the anomalously warm surrounding atmosphere. During AR90+ events in northwest Greenland, anomalous melt is forced remotely through a clear-sky foehn regime produced by down-slope flow in eastern Greenland. Article in Journal/Newspaper Greenland Ice Sheet University of Liège: ORBi (Open Repository and Bibliography) Journal of Climate 33 16 6809 6832 |
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 Mattingly, K. Mote, T. Fettweis, Xavier van As, D. Van Tricht, K. Lhermitte, S. Pettersen, C. Fausto, R. Strong Summer Atmospheric Rivers Trigger Greenland Ice Sheet Melt through Spatially Varying Surface Energy Balance and Cloud Regimes |
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 Mass loss from the Greenland Ice Sheet (GrIS) has accelerated over the past two decades, coincident with rapid Arctic warming and increasing moisture transport over Greenland by atmospheric rivers (ARs). Summer ARs affect- ing western Greenland trigger GrIS melt events, but the physical mechanisms through which ARs induce melt are not well understood. This study elu- cidates the coupled surface-atmosphere processes by which ARs force GrIS melt through analysis of the surface energy balance (SEB), cloud properties, and local- to synoptic-scale atmospheric conditions during strong summer AR events affecting western Greenland. ARs are identified in MERRA-2 reanal- ysis (1980–2017) and classified by integrated water vapor transport (IVT) intensity. SEB, cloud, and atmospheric data from regional climate model, observational, reanalysis, and satellite-based datasets are used to analyze melt-inducing physical processes during strong, > 90th percentile “AR90+ ” events. Near AR “landfall”, AR90+ days feature increased cloud cover that re- duces net shortwave radiation and increases net longwave radiation. As these oppositely-signed radiative anomalies partly cancel during AR90+ events, in- creased melt energy in the ablation zone is primarily provided by turbulent heat fluxes, particularly sensible heat flux. These turbulent heat fluxes are driven by enhanced barrier winds generated by a stronger synoptic pressure gradient combined with an enhanced local temperature contrast between cool over-ice air and the anomalously warm surrounding atmosphere. During AR90+ events in northwest Greenland, anomalous melt is forced remotely through a clear-sky foehn regime produced by down-slope flow in eastern Greenland. |
author2 |
Sphères - SPHERES |
format |
Article in Journal/Newspaper |
author |
Mattingly, K. Mote, T. Fettweis, Xavier van As, D. Van Tricht, K. Lhermitte, S. Pettersen, C. Fausto, R. |
author_facet |
Mattingly, K. Mote, T. Fettweis, Xavier van As, D. Van Tricht, K. Lhermitte, S. Pettersen, C. Fausto, R. |
author_sort |
Mattingly, K. |
title |
Strong Summer Atmospheric Rivers Trigger Greenland Ice Sheet Melt through Spatially Varying Surface Energy Balance and Cloud Regimes |
title_short |
Strong Summer Atmospheric Rivers Trigger Greenland Ice Sheet Melt through Spatially Varying Surface Energy Balance and Cloud Regimes |
title_full |
Strong Summer Atmospheric Rivers Trigger Greenland Ice Sheet Melt through Spatially Varying Surface Energy Balance and Cloud Regimes |
title_fullStr |
Strong Summer Atmospheric Rivers Trigger Greenland Ice Sheet Melt through Spatially Varying Surface Energy Balance and Cloud Regimes |
title_full_unstemmed |
Strong Summer Atmospheric Rivers Trigger Greenland Ice Sheet Melt through Spatially Varying Surface Energy Balance and Cloud Regimes |
title_sort |
strong summer atmospheric rivers trigger greenland ice sheet melt through spatially varying surface energy balance and cloud regimes |
publisher |
American Meteorological Society |
publishDate |
2020 |
url |
https://orbi.uliege.be/handle/2268/248320 https://orbi.uliege.be/bitstream/2268/248320/1/jcli-d-19-0835.1.pdf https://doi.org/10.1175/JCLI-D-19-0835.1 |
genre |
Greenland Ice Sheet |
genre_facet |
Greenland Ice Sheet |
op_source |
Journal of Climate (2020-06-09) |
op_relation |
https://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-19-0835.1 urn:issn:0894-8755 urn:issn:1520-0442 https://orbi.uliege.be/handle/2268/248320 info:hdl:2268/248320 https://orbi.uliege.be/bitstream/2268/248320/1/jcli-d-19-0835.1.pdf doi:10.1175/JCLI-D-19-0835.1 scopus-id:2-s2.0-85086476063 |
op_rights |
open access http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1175/JCLI-D-19-0835.1 |
container_title |
Journal of Climate |
container_volume |
33 |
container_issue |
16 |
container_start_page |
6809 |
op_container_end_page |
6832 |
_version_ |
1796942945916551168 |