气候变化领域集成服务门户(CCPortal): Aspect controls the survival of ice cliffs on debris-covered glaciers

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DOI	10.1073/pnas.1713892115
	Aspect controls the survival of ice cliffs on debris-covered glaciers
	Buri P.; Pellicciotti F.
发表日期	2018
ISSN	0027-8424
起始页码	4369
结束页码	4374
卷号	115 期号:17
英文摘要	Supraglacial ice cliffs exist on debris-covered glaciers worldwide, but despite their importance as melt hot spots, their life cycle is little understood. Early field observations had advanced a hypothesis of survival of north-facing and disappearance of south-facing cliffs, which is central for predicting the contribution of cliffs to total glacier mass losses. Their role as windows of energy transfer suggests they may explain the anomalously high mass losses of debris-covered glaciers in High Mountain Asia (HMA) despite the insulating debris, currently at the center of a debated controversy. We use a 3D model of cliff evolution coupled to very high-resolution topographic data to demonstrate that ice cliffs facing south (in the Northern Hemisphere) disappear within a few months due to enhanced solar radiation receipts and that aspect is the key control on cliffs evolution. We reproduce continuous flattening of south-facing cliffs, a result of their vertical gradient of incoming solar radiation and sky view factor. Our results establish that only north-facing cliffs are recurrent features and thus stable contributors to the melting of debris-covered glaciers. Satellite observations and mass balance modeling confirms that few south-facing cliffs of small size exist on the glaciers of Langtang, and their contribution to the glacier volume losses is very small (∼1%). This has major implications for the mass balance of HMA debris-covered glaciers as it provides the basis for new parameterizations of cliff evolution and distribution to constrain volume losses in a region where glaciers are highly relevant as water sources for millions of people. © 2018 National Academy of Sciences. All Rights Reserved.
英文关键词	Debris cover; Glaciers; High Mountain Asia; Ice cliffs; Modeling
语种	英语
scopus关键词	algorithm; Article; catchment; circadian rhythm; deglaciation; energy balance; glacial mass balance; glacier; hydrology; ice cliff; Nepal; Northern Hemisphere; priority journal; radiation; shortwave radiation; solar energy; solar radiation; topography; water supply; winter
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/158883
作者单位	Buri, P., Institute of Environmental Engineering, Hydrology and Water Resources Management Group, ETH Zürich, Zürich, 8093, Switzerland; Pellicciotti, F., Faculty of Engineering and Environment, Department of Geography, Northumbria University, Newcastle upon Tyne, NE18ST, United Kingdom
推荐引用方式 GB/T 7714	Buri P.,Pellicciotti F.. Aspect controls the survival of ice cliffs on debris-covered glaciers[J],2018,115(17).
APA	Buri P.,&Pellicciotti F..(2018).Aspect controls the survival of ice cliffs on debris-covered glaciers.Proceedings of the National Academy of Sciences of the United States of America,115(17).
MLA	Buri P.,et al."Aspect controls the survival of ice cliffs on debris-covered glaciers".Proceedings of the National Academy of Sciences of the United States of America 115.17(2018).