Using a circulation type classification to analyse the general circulation over Greenland simulated by GCMs
Future projections of the Greenland ice sheet melt are mainly based on General Circulation Model (GCM) outputs. The atmospheric circulation type classification offers a unique opportunity for validating the GCM-based circulations. Six GCMs used in the last IPCC report are analysed here. A correlatio...
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ftorbi:oai:orbi.ulg.ac.be:2268/78590 2024-04-21T08:03:19+00:00 Using a circulation type classification to analyse the general circulation over Greenland simulated by GCMs Belleflamme, Alexandre Fettweis, Xavier Erpicum, Michel 2010-11-23 14 https://orbi.uliege.be/handle/2268/78590 https://orbi.uliege.be/bitstream/2268/78590/1/a_belleflamme_cost733_finalevent.pdf en eng https://orbi.uliege.be/handle/2268/78590 info:hdl:2268/78590 https://orbi.uliege.be/bitstream/2268/78590/1/a_belleflamme_cost733_finalevent.pdf open access http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess COST733 Final Workshop, Vienna, Austria [AT], du 22 novembre 2010 au 24 novembre 2010 General Circulation Models Greenland Atmospheric circulation Atmospheric circulation type classification COST733 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 2010 ftorbi 2024-03-27T14:43:28Z Future projections of the Greenland ice sheet melt are mainly based on General Circulation Model (GCM) outputs. The atmospheric circulation type classification offers a unique opportunity for validating the GCM-based circulations. Six GCMs used in the last IPCC report are analysed here. A correlation-based classification is constructed for each model using daily geopotential height at 500 hPa over Greenland. It is applied to a dataset combining the GCM-based outputs (20C3M scenario) for the current climate and the NCEP-NCAR 1 reanalysis data over the period 1961-1990 allowing a direct comparison for each circulation type. Most of the analysed models are able to reproduce the main circulation types, but they fail to reproduce their frequencies because they underestimate the climate variability. In addition, some biases in the mean geopotential height remain. However, we use our atmospheric circulation type classification for analysing future projections made by GCMs. As for the 20th century climate, a combined classification is made integrating reanalysis data over 1971-1990, GCM-based outputs over 1971-1990 (using 20C3M scenario) and GCM-based outputs over 2046-2065 and 2081-2100 (using A1B scenario). No new circulation types are individualised knowing that the main changes are just a general increase of the geopotential height. Furthermore, the changes in frequency observed between the 20th century climate and the first future period (2046-2065) are of the same order than the uncertainties of the models for simulating the current climate by comparison with the reanalysis data. Therefore, the circulation type classification is a useful tool to give a precise analysis of the atmospheric circulation simulated by GCMs knowing that most of downscaling techniques are dependent on the general circulation simulated by the GCMs. Conference Object Greenland 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 |
General Circulation Models Greenland Atmospheric circulation Atmospheric circulation type classification COST733 Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique |
spellingShingle |
General Circulation Models Greenland Atmospheric circulation Atmospheric circulation type classification COST733 Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique Belleflamme, Alexandre Fettweis, Xavier Erpicum, Michel Using a circulation type classification to analyse the general circulation over Greenland simulated by GCMs |
topic_facet |
General Circulation Models Greenland Atmospheric circulation Atmospheric circulation type classification COST733 Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique |
description |
Future projections of the Greenland ice sheet melt are mainly based on General Circulation Model (GCM) outputs. The atmospheric circulation type classification offers a unique opportunity for validating the GCM-based circulations. Six GCMs used in the last IPCC report are analysed here. A correlation-based classification is constructed for each model using daily geopotential height at 500 hPa over Greenland. It is applied to a dataset combining the GCM-based outputs (20C3M scenario) for the current climate and the NCEP-NCAR 1 reanalysis data over the period 1961-1990 allowing a direct comparison for each circulation type. Most of the analysed models are able to reproduce the main circulation types, but they fail to reproduce their frequencies because they underestimate the climate variability. In addition, some biases in the mean geopotential height remain. However, we use our atmospheric circulation type classification for analysing future projections made by GCMs. As for the 20th century climate, a combined classification is made integrating reanalysis data over 1971-1990, GCM-based outputs over 1971-1990 (using 20C3M scenario) and GCM-based outputs over 2046-2065 and 2081-2100 (using A1B scenario). No new circulation types are individualised knowing that the main changes are just a general increase of the geopotential height. Furthermore, the changes in frequency observed between the 20th century climate and the first future period (2046-2065) are of the same order than the uncertainties of the models for simulating the current climate by comparison with the reanalysis data. Therefore, the circulation type classification is a useful tool to give a precise analysis of the atmospheric circulation simulated by GCMs knowing that most of downscaling techniques are dependent on the general circulation simulated by the GCMs. |
format |
Conference Object |
author |
Belleflamme, Alexandre Fettweis, Xavier Erpicum, Michel |
author_facet |
Belleflamme, Alexandre Fettweis, Xavier Erpicum, Michel |
author_sort |
Belleflamme, Alexandre |
title |
Using a circulation type classification to analyse the general circulation over Greenland simulated by GCMs |
title_short |
Using a circulation type classification to analyse the general circulation over Greenland simulated by GCMs |
title_full |
Using a circulation type classification to analyse the general circulation over Greenland simulated by GCMs |
title_fullStr |
Using a circulation type classification to analyse the general circulation over Greenland simulated by GCMs |
title_full_unstemmed |
Using a circulation type classification to analyse the general circulation over Greenland simulated by GCMs |
title_sort |
using a circulation type classification to analyse the general circulation over greenland simulated by gcms |
publishDate |
2010 |
url |
https://orbi.uliege.be/handle/2268/78590 https://orbi.uliege.be/bitstream/2268/78590/1/a_belleflamme_cost733_finalevent.pdf |
genre |
Greenland Ice Sheet |
genre_facet |
Greenland Ice Sheet |
op_source |
COST733 Final Workshop, Vienna, Austria [AT], du 22 novembre 2010 au 24 novembre 2010 |
op_relation |
https://orbi.uliege.be/handle/2268/78590 info:hdl:2268/78590 https://orbi.uliege.be/bitstream/2268/78590/1/a_belleflamme_cost733_finalevent.pdf |
op_rights |
open access http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess |
_version_ |
1796943224845107200 |