气候变化领域集成服务门户(CCPortal): Modelling rock wall permafrost degradation in the Mont Blanc massif from the LIA to the end of the 21st century

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DOI	10.5194/tc-11-1813-2017
	Modelling rock wall permafrost degradation in the Mont Blanc massif from the LIA to the end of the 21st century
	Magnin F.; Josnin J.-Y.; Ravanel L.; Pergaud J.; Pohl B.; Deline P.
发表日期	2017
ISSN	19940416
卷号	11 期号:4
英文摘要	High alpine rock wall permafrost is extremely sensitive to climate change. Its degradation has a strong impact on landscape evolution and can trigger rockfalls constituting an increasing threat to socio-economical activities of highly frequented areas; quantitative understanding of permafrost evolution is crucial for such communities. This study investigates the long-term evolution of permafrost in three vertical cross sections of rock wall sites between 3160 and 4300 m above sea level in the Mont Blanc massif, from the Little Ice Age (LIA) steady-state conditions to 2100. Simulations are forced with air temperature time series, including two contrasted air temperature scenarios for the 21st century representing possible lower and upper boundaries of future climate change according to the most recent models and climate change scenarios. The 2-D finite element model accounts for heat conduction and latent heat transfers, and the outputs for the current period (2010-2015) are evaluated against borehole temperature measurements and an electrical resistivity transect: permafrost conditions are remarkably well represented. Over the past two decades, permafrost has disappeared on faces with a southerly aspect up to 3300 m a.s.l. and possibly higher. Warm permafrost (i.e. >-2 °C) has extended up to 3300 and 3850 m a.s.l. in N and S-exposed faces respectively. During the 21st century, warm permafrost is likely to extend at least up to 4300 m a.s.l. on S-exposed rock walls and up to 3850 m a.s.l. depth on the N-exposed faces. In the most pessimistic case, permafrost will disappear on the S-exposed rock walls at a depth of up to 4300 m a.s.l., whereas warm permafrost will extend at a depth of the N faces up to 3850 m a.s.l., but possibly disappearing at such elevation under the influence of a close S face. The results are site specific and extrapolation to other sites is limited by the imbrication of local topographical and transient effects. © 2017 Author(s).
学科领域	air temperature; borehole; electrical resistivity; landscape evolution; latent heat flux; Little Ice Age; permafrost; time series analysis; topology; twentieth century; Alps; Haute Savoie; Mont Blanc; Savoy Alps; Western Alps
语种	英语
scopus关键词	air temperature; borehole; electrical resistivity; landscape evolution; latent heat flux; Little Ice Age; permafrost; time series analysis; topology; twentieth century; Alps; Haute Savoie; Mont Blanc; Savoy Alps; Western Alps
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/119362
作者单位	EDYTEM Lab, Université Savoie Mont Blanc, CNRS, Le Bourget du Lac, 73376, France; Centre de Recherches de Climatologie Biogéosciences, Université de Bourgogne Franche-Comté, CNRS, Dijon, France
推荐引用方式 GB/T 7714	Magnin F.,Josnin J.-Y.,Ravanel L.,et al. Modelling rock wall permafrost degradation in the Mont Blanc massif from the LIA to the end of the 21st century[J],2017,11(4).
APA	Magnin F.,Josnin J.-Y.,Ravanel L.,Pergaud J.,Pohl B.,&Deline P..(2017).Modelling rock wall permafrost degradation in the Mont Blanc massif from the LIA to the end of the 21st century.Cryosphere,11(4).
MLA	Magnin F.,et al."Modelling rock wall permafrost degradation in the Mont Blanc massif from the LIA to the end of the 21st century".Cryosphere 11.4(2017).