DOI: 10.5194/tc-9-2295-2015
Scopus记录号: 2-s2.0-84950105625
论文题名: Debris-covered glacier energy balance model for Imja-Lhotse Shar Glacier in the Everest region of Nepal
作者: Rounce D ; R ; , Quincey D ; J ; , McKinney D ; C
刊名: Cryosphere
ISSN: 19940416
出版年: 2015
卷: 9, 期: 6 起始页码: 2295
结束页码: 2310
语种: 英语
英文关键词: ablation
; albedo
; energy balance
; glacier
; latent heat flux
; surface energy
; surface roughness
; thermal conductivity
; Imja Glacier
; Lhotse Shar Glacier
; Nepal
; Sagarmatha [(ADS) Nepal]
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 glacier 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 the 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 glacier 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 the latent heat flux is zero 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., when 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. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75214
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: Center for Research in Water Resources, University of Texas at Austin, Austin, TX, United States; School of Geography, University of Leeds, Leeds, United Kingdom
Recommended Citation:
Rounce D,R,, Quincey D,et al. Debris-covered glacier energy balance model for Imja-Lhotse Shar Glacier in the Everest region of Nepal[J]. Cryosphere,2015-01-01,9(6)