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Global Warming Threshold and Mechanisms for Accelerated Greenland Ice Sheet Surface Mass Loss

The Community Earth System Model version 2.1 (CESM2.1) is used to investigate the evolution of the Greenland ice sheet (GrIS) surface mass balance (SMB) under an idealized CO(2) forcing scenario of 1% increase until stabilization at 4× pre‐industrial at model year 140. In this simulation, the SMB ca...

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Detalles Bibliográficos
Autores principales: Sellevold, Raymond, Vizcaíno, Miren
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7540049/
https://www.ncbi.nlm.nih.gov/pubmed/33042389
http://dx.doi.org/10.1029/2019MS002029
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author Sellevold, Raymond
Vizcaíno, Miren
author_facet Sellevold, Raymond
Vizcaíno, Miren
author_sort Sellevold, Raymond
collection PubMed
description The Community Earth System Model version 2.1 (CESM2.1) is used to investigate the evolution of the Greenland ice sheet (GrIS) surface mass balance (SMB) under an idealized CO(2) forcing scenario of 1% increase until stabilization at 4× pre‐industrial at model year 140. In this simulation, the SMB calculation is coupled with the atmospheric model, using a physically based surface energy balance scheme for melt, explicit calculation of snow albedo, and a realistic treatment of polar snow and firn compaction. By the end of the simulation (years 131–150), the SMB decreases with 994 Gt yr(−1) with respect to the pre‐industrial SMB, which represents a sea‐level rise contribution of 2.8 mm yr(−1). For a threshold of 2.7‐K global temperature increase with respect to pre‐industrial, the rate of expansion of the ablation area increases, the mass loss accelerates due to loss of refreezing capacity and accelerated melt, and the SMB becomes negative 6 years later. Before acceleration, longwave radiation is the most important contributor to increasing energy for melt. After acceleration, the large expansion of the ablation area strongly reduces surface albedo. This and much increased turbulent heat fluxes as the GrIS‐integrated summer surface temperature approaches melt point become the major sources of energy for melt.
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spelling pubmed-75400492020-10-09 Global Warming Threshold and Mechanisms for Accelerated Greenland Ice Sheet Surface Mass Loss Sellevold, Raymond Vizcaíno, Miren J Adv Model Earth Syst Research Articles The Community Earth System Model version 2.1 (CESM2.1) is used to investigate the evolution of the Greenland ice sheet (GrIS) surface mass balance (SMB) under an idealized CO(2) forcing scenario of 1% increase until stabilization at 4× pre‐industrial at model year 140. In this simulation, the SMB calculation is coupled with the atmospheric model, using a physically based surface energy balance scheme for melt, explicit calculation of snow albedo, and a realistic treatment of polar snow and firn compaction. By the end of the simulation (years 131–150), the SMB decreases with 994 Gt yr(−1) with respect to the pre‐industrial SMB, which represents a sea‐level rise contribution of 2.8 mm yr(−1). For a threshold of 2.7‐K global temperature increase with respect to pre‐industrial, the rate of expansion of the ablation area increases, the mass loss accelerates due to loss of refreezing capacity and accelerated melt, and the SMB becomes negative 6 years later. Before acceleration, longwave radiation is the most important contributor to increasing energy for melt. After acceleration, the large expansion of the ablation area strongly reduces surface albedo. This and much increased turbulent heat fluxes as the GrIS‐integrated summer surface temperature approaches melt point become the major sources of energy for melt. John Wiley and Sons Inc. 2020-09-09 2020-09 /pmc/articles/PMC7540049/ /pubmed/33042389 http://dx.doi.org/10.1029/2019MS002029 Text en ©2020. The Authors. This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Articles
Sellevold, Raymond
Vizcaíno, Miren
Global Warming Threshold and Mechanisms for Accelerated Greenland Ice Sheet Surface Mass Loss
title Global Warming Threshold and Mechanisms for Accelerated Greenland Ice Sheet Surface Mass Loss
title_full Global Warming Threshold and Mechanisms for Accelerated Greenland Ice Sheet Surface Mass Loss
title_fullStr Global Warming Threshold and Mechanisms for Accelerated Greenland Ice Sheet Surface Mass Loss
title_full_unstemmed Global Warming Threshold and Mechanisms for Accelerated Greenland Ice Sheet Surface Mass Loss
title_short Global Warming Threshold and Mechanisms for Accelerated Greenland Ice Sheet Surface Mass Loss
title_sort global warming threshold and mechanisms for accelerated greenland ice sheet surface mass loss
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7540049/
https://www.ncbi.nlm.nih.gov/pubmed/33042389
http://dx.doi.org/10.1029/2019MS002029
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