DOI: 10.5194/tc-8-1149-2014
Scopus记录号: 2-s2.0-84903991426
论文题名: High-resolution modelling of the seasonal evolution of surface water storage on the Greenland Ice Sheet
作者: Arnold N ; S ; , Banwell A ; F ; , Willis I ; C
刊名: Cryosphere
ISSN: 19940416
出版年: 2014
卷: 8, 期: 4 起始页码: 1149
结束页码: 1160
语种: 英语
英文关键词: drainage
; flow modeling
; glacial hydrology
; lake ecosystem
; mass balance
; meltwater
; runoff
; seasonal variation
; subglacial environment
; Arctic
; Greenland
; Greenland Ice Sheet
英文摘要: Seasonal meltwater lakes on the Greenland Ice Sheet form when surface runoff is temporarily trapped in surface topographic depressions. The development of such lakes affects both the surface energy balance and dynamics of the ice sheet. Although areal extents, depths and lifespan of lakes can be inferred from satellite imagery, such observational studies have a limited temporal resolution. Here, we adopt a modelling-based strategy to estimate the seasonal evolution of surface water storage for the ∼ 3600 km2 Paakitsoq region of W. Greenland. We use a high-resolution time-dependent surface mass balance model to calculate surface melt, a supraglacial water routing model to calculate lake filling and a prescribed water-volume-based threshold to predict rapid lake drainage events. This threshold assumes that drainage will occur through a fracture if V Combining double low line Fa H, where V is lake volume, H is the local ice thickness and Fa is the potential fracture area. The model shows good agreement between modelled lake locations and volumes and those observed in nine Landsat 7 ETM images from 2001, 2002 and 2005. We use the model to investigate the lake water volume required to trigger drainage, and the impact that varying this threshold volume has on the proportion of meltwater that is stored in surface lakes and enters the subglacial drainage system. Model performance is maximised with values of F a between 4000 and 7500 m2. For these thresholds, lakes transiently store < 40% of available meltwater at the beginning of the melt season, decreasing to ∼ 5 to 10% by the middle of the melt season; over the course of a melt season, 40 to 50% of total meltwater production enters the subglacial drainage system through moulins at the bottom of drained lakes. © Author(s) 2014. CC Attribution 3.0 License. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/74828
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: Scott Polar Research Institute, University of Cambridge, Lancefield Road, Cambridge CB2 1ER, United Kingdom
Recommended Citation:
Arnold N,S,, Banwell A,et al. High-resolution modelling of the seasonal evolution of surface water storage on the Greenland Ice Sheet[J]. Cryosphere,2014-01-01,8(4)