气候变化领域集成服务门户(CCPortal): The influence of water percolation through crevasses on the thermal regime of a Himalayan mountain glacier

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DOI	10.5194/tc-14-1273-2020
	The influence of water percolation through crevasses on the thermal regime of a Himalayan mountain glacier
	Gilbert A.; Sinisalo A.; R. Gurung T.; Fujita K.; B. Maharjan S.; C. Sherpa T.; Fukuda T.
发表日期	2020
ISSN	19940416
起始页码	1273
结束页码	1288
卷号	14 期号:4
英文摘要	In cold and arid climates, small glaciers with cold accumulation zones are often thought to be entirely cold based. However, scattering in ground-penetrating radar (GPR) measurements on the Rikha Samba Glacier in the Nepal Himalayas suggests a large amount of temperate ice that seems to be influenced by the presence of crevassed areas. We used a coupled thermo-mechanical model forced by a firn model accounting for firn heating to interpret the observed thermal regime. Using a simple energy conservation approach, we show that the addition of water percolation and refreezing in crevassed areas explains these observations. Model experiments show that both steady and transient thermal regimes are significantly affected by latent heat release in crevassed areas. This makes half of the glacier base temperate, resulting in an ice dynamic mainly controlled by basal friction instead of ice deformation. The timescale of thermal regime change, in response to atmospheric warming, is also greatly diminished, with a potential switch from cold to temperate basal ice in 50-60 years in the upper part of the glacier instead of the 100-150 years that it would take without the effect of the crevasses. This study highlights the crucial role of water percolation through the crevasses on the thermal regime of glaciers and validates a simple method to account for it in glacier thermo-mechanical models. © 2020 Copernicus GmbH. All rights reserved.
英文关键词	atmospheric modeling; energy conservation; glacier; ground penetrating radar; percolation; thermal regime; timescale; warming; Himalayas; India; Jammu and Kashmir; Nepal; Samba
语种	英语
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/202083
作者单位	Department of Geosciences, University of Oslo, Oslo, Norway; International Centre for Integrated Mountain Development, P.O. Box 3226, Kathmandu, Nepal; Graduate School of Environmental Studies, Nagoya University, Nagoya, 464-8601, Japan; Graduate School of Environmental Science, Hokkaido University, Sapporo, 060-0810, Japan; Institute of Low Temperature Science, Hokkaido University, Sapporo, 060-0819, Japan; GRID, Arendal, Norway; Hokkaido Government, Sapporo, 060-8588, Japan
推荐引用方式 GB/T 7714	Gilbert A.,Sinisalo A.,R. Gurung T.,et al. The influence of water percolation through crevasses on the thermal regime of a Himalayan mountain glacier[J],2020,14(4).
APA	Gilbert A..,Sinisalo A..,R. Gurung T..,Fujita K..,B. Maharjan S..,...&Fukuda T..(2020).The influence of water percolation through crevasses on the thermal regime of a Himalayan mountain glacier.Cryosphere,14(4).
MLA	Gilbert A.,et al."The influence of water percolation through crevasses on the thermal regime of a Himalayan mountain glacier".Cryosphere 14.4(2020).