21st century high-resolution downscaling of the Antarctic surface mass balance from global circulation models
Most of the IPCC-AR4 Atmospheric Global Circulation Models (AGCM) predict an increase of the Antarctic Surface Mass Balance (SMB) during the 21st century that would mitigate global sea level rise. Present accumulation and predicted change are largest at the ice sheet margins because they are driven...
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ftorbi:oai:orbi.ulg.ac.be:2268/169670 2024-04-21T07:51:00+00:00 21st century high-resolution downscaling of the Antarctic surface mass balance from global circulation models Agosta, Cécile Favier, Vincent Genthon, Christophe Gallée, Hubert Krinner, Gerhard 2011-04 https://orbi.uliege.be/handle/2268/169670 https://orbi.uliege.be/bitstream/2268/169670/1/Agosta_EGU2011_V2.pdf en eng info:eu-repo/grantAgreement/EC/FP7/226375 https://orbi.uliege.be/handle/2268/169670 info:hdl:2268/169670 https://orbi.uliege.be/bitstream/2268/169670/1/Agosta_EGU2011_V2.pdf open access http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess European Geosciences Union General Assembly 2011, Vienne, Austria [AT], du 4 avril au 8 avril 2011 surface mass balance Antarctic projection sea-level downscaling surface energy balance Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique conference paper not in proceedings http://purl.org/coar/resource_type/c_18cp info:eu-repo/semantics/conferencePaper 2011 ftorbi 2024-03-27T14:46:01Z Most of the IPCC-AR4 Atmospheric Global Circulation Models (AGCM) predict an increase of the Antarctic Surface Mass Balance (SMB) during the 21st century that would mitigate global sea level rise. Present accumulation and predicted change are largest at the ice sheet margins because they are driven by snowfall, which mostly comes from warm, moist air arising over the land slopes. The coastal belt is also where complex processes of sublimation, melt and redistribution by the wind occur. Thus, high-resolution modelling (5 to 10 km) is necessary to adequately capture the effects of small-scale variations in topography on the atmospheric variables in this area, but limitations in computing resources prevent such resolution at the scale of Antarctica in full climate models. We present here a downscaling method leading to 10-km SMB resolution for century time-scales over Antarctica. We compute the effect of the fine topography on orographic precipitation and on boundary layer processes that lead to melt and sublimation. We show that the accumulation downscaled from ERA-Interim is in good agreement with field measurements for the last 40 years. We then display the SMB downscaled from LMDZ4 AGCM outputs (~60-km resolution), and show that the downscaling improves the agreement between present modelled and observed SMB. Finally, we present hi-resolution features of the Antarctic SMB evolution during the 21st century downscaled from LMDZ4 and discuss the effect of the resolution on the Antarctic SMB contribution to sea level change. The downscaling model is a powerful tool that will be applied to others climate models for a better assessment of future sea level rise. Conference Object Antarc* Antarctic Antarctica Ice Sheet University of Liège: ORBi (Open Repository and Bibliography) |
institution |
Open Polar |
collection |
University of Liège: ORBi (Open Repository and Bibliography) |
op_collection_id |
ftorbi |
language |
English |
topic |
surface mass balance Antarctic projection sea-level downscaling surface energy balance Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique |
spellingShingle |
surface mass balance Antarctic projection sea-level downscaling surface energy balance Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique Agosta, Cécile Favier, Vincent Genthon, Christophe Gallée, Hubert Krinner, Gerhard 21st century high-resolution downscaling of the Antarctic surface mass balance from global circulation models |
topic_facet |
surface mass balance Antarctic projection sea-level downscaling surface energy balance Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique |
description |
Most of the IPCC-AR4 Atmospheric Global Circulation Models (AGCM) predict an increase of the Antarctic Surface Mass Balance (SMB) during the 21st century that would mitigate global sea level rise. Present accumulation and predicted change are largest at the ice sheet margins because they are driven by snowfall, which mostly comes from warm, moist air arising over the land slopes. The coastal belt is also where complex processes of sublimation, melt and redistribution by the wind occur. Thus, high-resolution modelling (5 to 10 km) is necessary to adequately capture the effects of small-scale variations in topography on the atmospheric variables in this area, but limitations in computing resources prevent such resolution at the scale of Antarctica in full climate models. We present here a downscaling method leading to 10-km SMB resolution for century time-scales over Antarctica. We compute the effect of the fine topography on orographic precipitation and on boundary layer processes that lead to melt and sublimation. We show that the accumulation downscaled from ERA-Interim is in good agreement with field measurements for the last 40 years. We then display the SMB downscaled from LMDZ4 AGCM outputs (~60-km resolution), and show that the downscaling improves the agreement between present modelled and observed SMB. Finally, we present hi-resolution features of the Antarctic SMB evolution during the 21st century downscaled from LMDZ4 and discuss the effect of the resolution on the Antarctic SMB contribution to sea level change. The downscaling model is a powerful tool that will be applied to others climate models for a better assessment of future sea level rise. |
format |
Conference Object |
author |
Agosta, Cécile Favier, Vincent Genthon, Christophe Gallée, Hubert Krinner, Gerhard |
author_facet |
Agosta, Cécile Favier, Vincent Genthon, Christophe Gallée, Hubert Krinner, Gerhard |
author_sort |
Agosta, Cécile |
title |
21st century high-resolution downscaling of the Antarctic surface mass balance from global circulation models |
title_short |
21st century high-resolution downscaling of the Antarctic surface mass balance from global circulation models |
title_full |
21st century high-resolution downscaling of the Antarctic surface mass balance from global circulation models |
title_fullStr |
21st century high-resolution downscaling of the Antarctic surface mass balance from global circulation models |
title_full_unstemmed |
21st century high-resolution downscaling of the Antarctic surface mass balance from global circulation models |
title_sort |
21st century high-resolution downscaling of the antarctic surface mass balance from global circulation models |
publishDate |
2011 |
url |
https://orbi.uliege.be/handle/2268/169670 https://orbi.uliege.be/bitstream/2268/169670/1/Agosta_EGU2011_V2.pdf |
genre |
Antarc* Antarctic Antarctica Ice Sheet |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet |
op_source |
European Geosciences Union General Assembly 2011, Vienne, Austria [AT], du 4 avril au 8 avril 2011 |
op_relation |
info:eu-repo/grantAgreement/EC/FP7/226375 https://orbi.uliege.be/handle/2268/169670 info:hdl:2268/169670 https://orbi.uliege.be/bitstream/2268/169670/1/Agosta_EGU2011_V2.pdf |
op_rights |
open access http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess |
_version_ |
1796934515163136000 |