气候变化领域集成服务门户(CCPortal): Debris-covered energy balance model for Imja-Lhotse Shar Glacier in the Everest region of Nepal

CCPortal

DOI	10.5194/tcd-9-3503-2015
	Debris-covered energy balance model for Imja-Lhotse Shar Glacier in the Everest region of Nepal
	Rounce D.R.; Quincey D.J.; McKinney D.C.
发表日期	2015
ISSN	19940432
卷号	9 期号:3
英文摘要	Debris thickness plays an important role in regulating ablation rates on debris-covered glaciers as well as controlling the likely size and location of supraglacial lakes. Despite its importance, lack of knowledge about debris properties and associated energy fluxes prevents the robust inclusion of the effects of a debris layer into most glacier surface energy balance models. This study combines fieldwork with a debris-covered energy balance model to estimate debris temperatures and ablation rates on Imja-Lhotse Shar glacier located in the Everest region of Nepal. The debris properties that significantly influence the energy balance model are thermal conductivity, albedo, and surface roughness. Fieldwork was conducted to measure thermal conductivity and a method was developed using Structure from Motion to estimate surface roughness. Debris temperatures measured during the 2014 melt season were used to calibrate and validate a debris-covered energy balance model by optimizing the albedo, thermal conductivity, and surface roughness at 10 debris-covered sites. Furthermore, three methods for estimating the latent heat flux were investigated. Model calibration and validation found the three methods had similar performance; however, comparison of modeled and measured ablation rates revealed that assuming a zero latent heat flux may overestimate ablation. Results also suggest that where debris moisture is unknown, measurements of the relative humidity or precipitation may be used to estimate wet debris periods, i.e., the latent heat flux is non-zero. The effect of temporal resolution on the model was also assessed and results showed that both 6 h data and daily average data slightly underestimate debris temperatures and ablation rates, thus these should only be used to estimate rough ablation rates when no other data are available. © Author(s) 2015.
学科领域	ablation; albedo; debris flow; energy balance; energy flux; ephemeral lake; fieldwork; glacier; latent heat flux; pond; precipitation (climatology); relative humidity; surface energy; surface roughness; thermal conductivity; Imja-Lhoste Shar Glacier; Nepal
语种	英语
scopus关键词	ablation; albedo; debris flow; energy balance; energy flux; ephemeral lake; fieldwork; glacier; latent heat flux; pond; precipitation (climatology); relative humidity; surface energy; surface roughness; thermal conductivity; Imja-Lhoste Shar Glacier; Nepal
来源期刊	Cryosphere Discussions
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/119873
作者单位	Center for Research in Water Resources, University of Texas at Austin, Austin, TX, United States; School of Geography, University of Leeds, Leeds, LS2 9JT, United Kingdom
推荐引用方式 GB/T 7714	Rounce D.R.,Quincey D.J.,McKinney D.C.. Debris-covered energy balance model for Imja-Lhotse Shar Glacier in the Everest region of Nepal[J],2015,9(3).
APA	Rounce D.R.,Quincey D.J.,&McKinney D.C..(2015).Debris-covered energy balance model for Imja-Lhotse Shar Glacier in the Everest region of Nepal.Cryosphere Discussions,9(3).
MLA	Rounce D.R.,et al."Debris-covered energy balance model for Imja-Lhotse Shar Glacier in the Everest region of Nepal".Cryosphere Discussions 9.3(2015).