Evaluation of the CMIP5 models in the aim of regional modelling of the Antarctic surface mass balance

The surface mass balance (SMB) of the Antarctic Ice Sheet cannot be reliably deduced from global climate models (GCMs), both because their spatial resolution is insufficient and because their physics are not adapted for cold and snow-covered regions. By contrast, regional climate models (RCMs) adapt...

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Main Authors: C. Agosta, X. Fettweis, R. Datta
Format: Article
Language:English
Published: Copernicus Publications 2015-12-01
Series:The Cryosphere
Online Access:http://www.the-cryosphere.net/9/2311/2015/tc-9-2311-2015.pdf
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author C. Agosta
X. Fettweis
R. Datta
author_facet C. Agosta
X. Fettweis
R. Datta
author_sort C. Agosta
collection DOAJ
description The surface mass balance (SMB) of the Antarctic Ice Sheet cannot be reliably deduced from global climate models (GCMs), both because their spatial resolution is insufficient and because their physics are not adapted for cold and snow-covered regions. By contrast, regional climate models (RCMs) adapted for polar regions can physically and dynamically downscale SMB components over the ice sheet using large-scale forcing at their boundaries. Polar-oriented RCMs require appropriate GCM fields for forcing because the response of the cryosphere to a warming climate is dependent on its initial state and is not linear with respect to temperature increase. In this context, we evaluate the current climate in 41 climate models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) data set over Antarctica by focusing on forcing fields which may have the greatest impact on SMB components simulated by RCMs. Our inter-comparison includes six reanalyses, among which ERA-Interim reanalysis is chosen as a reference over 1979–2014. Model efficiency is assessed taking into account the multi-decadal variability of the fields over the 1850–1980 period. We show that fewer than 10 CMIP5 models show reasonable biases compared to ERA-Interim, among which ACCESS1-3 is the most pertinent choice for forcing RCMs over Antarctica, followed by ACCESS1-0, CESM1-BGC, CESM1-CAM5, NorESM1-M, CCSM4 and EC-EARTH. Finally, climate change over the Southern Ocean in CMIP5 is less sensitive to the global warming signal than it is to the present-day simulated sea-ice extent and to the feedback between sea-ice decrease and air temperature increase around Antarctica.
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spelling doaj.art-87c3642487da4cd9b2e9d71a1c115aab2022-12-22T03:51:54ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242015-12-01962311232110.5194/tc-9-2311-2015Evaluation of the CMIP5 models in the aim of regional modelling of the Antarctic surface mass balanceC. Agosta0X. Fettweis1R. Datta2Department of Geography, Université de Liège, Liège, BelgiumDepartment of Geography, Université de Liège, Liège, BelgiumThe Graduate Center, City University of New York, NY 10016, USAThe surface mass balance (SMB) of the Antarctic Ice Sheet cannot be reliably deduced from global climate models (GCMs), both because their spatial resolution is insufficient and because their physics are not adapted for cold and snow-covered regions. By contrast, regional climate models (RCMs) adapted for polar regions can physically and dynamically downscale SMB components over the ice sheet using large-scale forcing at their boundaries. Polar-oriented RCMs require appropriate GCM fields for forcing because the response of the cryosphere to a warming climate is dependent on its initial state and is not linear with respect to temperature increase. In this context, we evaluate the current climate in 41 climate models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) data set over Antarctica by focusing on forcing fields which may have the greatest impact on SMB components simulated by RCMs. Our inter-comparison includes six reanalyses, among which ERA-Interim reanalysis is chosen as a reference over 1979–2014. Model efficiency is assessed taking into account the multi-decadal variability of the fields over the 1850–1980 period. We show that fewer than 10 CMIP5 models show reasonable biases compared to ERA-Interim, among which ACCESS1-3 is the most pertinent choice for forcing RCMs over Antarctica, followed by ACCESS1-0, CESM1-BGC, CESM1-CAM5, NorESM1-M, CCSM4 and EC-EARTH. Finally, climate change over the Southern Ocean in CMIP5 is less sensitive to the global warming signal than it is to the present-day simulated sea-ice extent and to the feedback between sea-ice decrease and air temperature increase around Antarctica.http://www.the-cryosphere.net/9/2311/2015/tc-9-2311-2015.pdf
spellingShingle C. Agosta
X. Fettweis
R. Datta
Evaluation of the CMIP5 models in the aim of regional modelling of the Antarctic surface mass balance
The Cryosphere
title Evaluation of the CMIP5 models in the aim of regional modelling of the Antarctic surface mass balance
title_full Evaluation of the CMIP5 models in the aim of regional modelling of the Antarctic surface mass balance
title_fullStr Evaluation of the CMIP5 models in the aim of regional modelling of the Antarctic surface mass balance
title_full_unstemmed Evaluation of the CMIP5 models in the aim of regional modelling of the Antarctic surface mass balance
title_short Evaluation of the CMIP5 models in the aim of regional modelling of the Antarctic surface mass balance
title_sort evaluation of the cmip5 models in the aim of regional modelling of the antarctic surface mass balance
url http://www.the-cryosphere.net/9/2311/2015/tc-9-2311-2015.pdf
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AT rdatta evaluationofthecmip5modelsintheaimofregionalmodellingoftheantarcticsurfacemassbalance