The darkening of the Greenland ice sheet: trends, drivers, and projections (1981–2100)
peer reviewed The surface energy balance and meltwater production of the Greenland ice sheet (GrIS) are modulated by snow and ice albedo through the amount of absorbed solar radiation. Here we show, using space-borne multispectral data collected during the 3 decades from 1981 to 2012, that summertim...
Published in: | The Cryosphere |
---|---|
Main Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus
2016
|
Subjects: | |
Online Access: | https://orbi.uliege.be/handle/2268/194220 https://orbi.uliege.be/bitstream/2268/194220/1/tc-10-477-2016.pdf https://doi.org/10.5194/tc-10-477-2016 |
id |
ftorbi:oai:orbi.ulg.ac.be:2268/194220 |
---|---|
record_format |
openpolar |
spelling |
ftorbi:oai:orbi.ulg.ac.be:2268/194220 2024-04-21T08:03:32+00:00 The darkening of the Greenland ice sheet: trends, drivers, and projections (1981–2100) Tedesco, M. Doherty, S. Fettweis, Xavier Alexander, P. Jeyaratnam, J. Stroeve, J. 2016-03-03 https://orbi.uliege.be/handle/2268/194220 https://orbi.uliege.be/bitstream/2268/194220/1/tc-10-477-2016.pdf https://doi.org/10.5194/tc-10-477-2016 en eng Copernicus http://www.the-cryosphere.net/10/477/2016/ urn:issn:1994-0416 urn:issn:1994-0424 https://orbi.uliege.be/handle/2268/194220 info:hdl:2268/194220 https://orbi.uliege.be/bitstream/2268/194220/1/tc-10-477-2016.pdf doi:10.5194/tc-10-477-2016 scopus-id:2-s2.0-84960094017 open access http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess The Cryosphere, 10, 477-496 (2016-03-03) 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 2016 ftorbi https://doi.org/10.5194/tc-10-477-2016 2024-03-27T14:58:15Z peer reviewed The surface energy balance and meltwater production of the Greenland ice sheet (GrIS) are modulated by snow and ice albedo through the amount of absorbed solar radiation. Here we show, using space-borne multispectral data collected during the 3 decades from 1981 to 2012, that summertime surface albedo over the GrIS decreased at a statistically significant (99 %) rate of 0.02 decade−1 between 1996 and 2012. Over the same period, albedo modelled by the Modèle Atmosphérique Régionale (MAR) also shows a decrease, though at a lower rate ( ∼ −0.01 decade−1) than that obtained from space-borne data. We suggest that the discrepancy between modelled and measured albedo trends can be explained by the absence in the model of processes associated with the presence of light-absorbing impurities. The negative trend in observed albedo is confined to the regions of the GrIS that undergo melting in summer, with the dry-snow zone showing no trend. The period 1981–1996 also showed no statistically significant trend over the whole GrIS. Analysis of MAR outputs indicates that the observed albedo decrease is attributable to the combined effects of increased near-surface air temperatures, which enhanced melt and promoted growth in snow grain size and the expansion of bare ice areas, and to trends in light-absorbing impurities (LAI) on the snow and ice surfaces. Neither aerosol models nor in situ and remote sensing observations indicate increasing trends in LAI in the atmosphere over Greenland. Similarly, an analysis of the number of fires and BC emissions from fires points to the absence of trends for such quantities. This suggests that the apparent increase of LAI in snow and ice might be related to the exposure of a "dark band" of dirty ice and to increased consolidation of LAI at the surface with melt, not to increased aerosol deposition. Albedo projections through to the end of the century under different warming scenarios consistently point to continued darkening, with albedo anomalies averaged over the whole ice ... Article in Journal/Newspaper Greenland Ice Sheet The Cryosphere University of Liège: ORBi (Open Repository and Bibliography) The Cryosphere 10 2 477 496 |
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 Tedesco, M. Doherty, S. Fettweis, Xavier Alexander, P. Jeyaratnam, J. Stroeve, J. The darkening of the Greenland ice sheet: trends, drivers, and projections (1981–2100) |
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 The surface energy balance and meltwater production of the Greenland ice sheet (GrIS) are modulated by snow and ice albedo through the amount of absorbed solar radiation. Here we show, using space-borne multispectral data collected during the 3 decades from 1981 to 2012, that summertime surface albedo over the GrIS decreased at a statistically significant (99 %) rate of 0.02 decade−1 between 1996 and 2012. Over the same period, albedo modelled by the Modèle Atmosphérique Régionale (MAR) also shows a decrease, though at a lower rate ( ∼ −0.01 decade−1) than that obtained from space-borne data. We suggest that the discrepancy between modelled and measured albedo trends can be explained by the absence in the model of processes associated with the presence of light-absorbing impurities. The negative trend in observed albedo is confined to the regions of the GrIS that undergo melting in summer, with the dry-snow zone showing no trend. The period 1981–1996 also showed no statistically significant trend over the whole GrIS. Analysis of MAR outputs indicates that the observed albedo decrease is attributable to the combined effects of increased near-surface air temperatures, which enhanced melt and promoted growth in snow grain size and the expansion of bare ice areas, and to trends in light-absorbing impurities (LAI) on the snow and ice surfaces. Neither aerosol models nor in situ and remote sensing observations indicate increasing trends in LAI in the atmosphere over Greenland. Similarly, an analysis of the number of fires and BC emissions from fires points to the absence of trends for such quantities. This suggests that the apparent increase of LAI in snow and ice might be related to the exposure of a "dark band" of dirty ice and to increased consolidation of LAI at the surface with melt, not to increased aerosol deposition. Albedo projections through to the end of the century under different warming scenarios consistently point to continued darkening, with albedo anomalies averaged over the whole ice ... |
format |
Article in Journal/Newspaper |
author |
Tedesco, M. Doherty, S. Fettweis, Xavier Alexander, P. Jeyaratnam, J. Stroeve, J. |
author_facet |
Tedesco, M. Doherty, S. Fettweis, Xavier Alexander, P. Jeyaratnam, J. Stroeve, J. |
author_sort |
Tedesco, M. |
title |
The darkening of the Greenland ice sheet: trends, drivers, and projections (1981–2100) |
title_short |
The darkening of the Greenland ice sheet: trends, drivers, and projections (1981–2100) |
title_full |
The darkening of the Greenland ice sheet: trends, drivers, and projections (1981–2100) |
title_fullStr |
The darkening of the Greenland ice sheet: trends, drivers, and projections (1981–2100) |
title_full_unstemmed |
The darkening of the Greenland ice sheet: trends, drivers, and projections (1981–2100) |
title_sort |
darkening of the greenland ice sheet: trends, drivers, and projections (1981–2100) |
publisher |
Copernicus |
publishDate |
2016 |
url |
https://orbi.uliege.be/handle/2268/194220 https://orbi.uliege.be/bitstream/2268/194220/1/tc-10-477-2016.pdf https://doi.org/10.5194/tc-10-477-2016 |
genre |
Greenland Ice Sheet The Cryosphere |
genre_facet |
Greenland Ice Sheet The Cryosphere |
op_source |
The Cryosphere, 10, 477-496 (2016-03-03) |
op_relation |
http://www.the-cryosphere.net/10/477/2016/ urn:issn:1994-0416 urn:issn:1994-0424 https://orbi.uliege.be/handle/2268/194220 info:hdl:2268/194220 https://orbi.uliege.be/bitstream/2268/194220/1/tc-10-477-2016.pdf doi:10.5194/tc-10-477-2016 scopus-id:2-s2.0-84960094017 |
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-10-477-2016 |
container_title |
The Cryosphere |
container_volume |
10 |
container_issue |
2 |
container_start_page |
477 |
op_container_end_page |
496 |
_version_ |
1796943347796934656 |