气候变化领域集成服务门户(CCPortal): Modeling debris-covered glaciers: Response to steady debris deposition

CCPortal

DOI	10.5194/tc-10-1105-2016
	Modeling debris-covered glaciers: Response to steady debris deposition
	Anderson L.S.; Anderson R.S.
发表日期	2016
ISSN	19940416
卷号	10 期号:3
英文摘要	Debris-covered glaciers are common in rapidly eroding alpine landscapes. When thicker than a few centimeters, surface debris suppresses melt rates. If continuous debris cover is present, ablation rates can be significantly reduced leading to increases in glacier length. In order to quantify feedbacks in the debris-glacier-climate system, we developed a 2-D long-valley numerical glacier model that includes englacial and supraglacial debris advection. We ran 120 simulations on a linear bed profile in which a hypothetical steady state debris-free glacier responds to a step increase of surface debris deposition. Simulated glaciers advance to steady states in which ice accumulation equals ice ablation, and debris input equals debris loss from the glacier terminus. Our model and parameter selections can produce 2-fold increases in glacier length. Debris flux onto the glacier and the relationship between debris thickness and melt rate strongly control glacier length. Debris deposited near the equilibriumline altitude, where ice discharge is high, results in the greatest glacier extension when other debris-related variables are held constant. Debris deposited near the equilibrium-line altitude re-emerges high in the ablation zone and therefore impacts melt rate over a greater fraction of the glacier surface. Continuous debris cover reduces ice discharge gradients, ice thickness gradients, and velocity gradients relative to initial debris-free glaciers. Debris-forced glacier extension decreases the ratio of accumulation zone to total glacier area (AAR). Our simulations reproduce the "general trends" between debris cover, AARs, and glacier surface velocity patterns from modern debris-covered glaciers. We provide a quantitative, theoretical foundation to interpret the effect of debris cover on the moraine record, and to assess the effects of climate change on debris-covered glaciers. © 2016 Author(s).
学科领域	ablation; advection; alpine environment; climate change; debris flow; flow velocity; glacial debris; glacier mass balance; ice drift; ice thickness; snow avalanche
语种	英语
scopus关键词	ablation; advection; alpine environment; climate change; debris flow; flow velocity; glacial debris; glacier mass balance; ice drift; ice thickness; snow avalanche
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/119642
作者单位	Institute of Earth Sciences, University of Iceland, Sturlugotu 7, Reykjavik, 101, Iceland; Institute of Arctic and Alpine Research, Department of Geological Sciences, University of Colorado, Boulder, CO 80309, United States
推荐引用方式 GB/T 7714	Anderson L.S.,Anderson R.S.. Modeling debris-covered glaciers: Response to steady debris deposition[J],2016,10(3).
APA	Anderson L.S.,&Anderson R.S..(2016).Modeling debris-covered glaciers: Response to steady debris deposition.Cryosphere,10(3).
MLA	Anderson L.S.,et al."Modeling debris-covered glaciers: Response to steady debris deposition".Cryosphere 10.3(2016).