DOI: 10.5194/tc-11-1813-2017
Scopus记录号: 2-s2.0-85027014116
论文题名: Modelling rock wall permafrost degradation in the Mont Blanc massif from the LIA to the end of the 21st century
作者: Magnin F ; , Josnin J ; -Y ; , Ravanel L ; , Pergaud J ; , Pohl B ; , Deline P
刊名: Cryosphere
ISSN: 19940416
出版年: 2017
卷: 11, 期: 4 起始页码: 1813
结束页码: 1834
语种: 英语
英文关键词: 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
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). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75520
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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作者单位: EDYTEM Lab, Université Savoie Mont Blanc, CNRS, Le Bourget du Lac, France; Centre de Recherches de Climatologie Biogéosciences, Université de Bourgogne Franche-Comté, CNRS, Dijon, France
Recommended Citation:
Magnin F,, Josnin J,-Y,et al. Modelling rock wall permafrost degradation in the Mont Blanc massif from the LIA to the end of the 21st century[J]. Cryosphere,2017-01-01,11(4)