气候变化领域集成服务门户(CCPortal): High-resolution modelling of the seasonal evolution of surface water storage on the Greenland Ice Sheet

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DOI	10.5194/tc-8-1149-2014
	High-resolution modelling of the seasonal evolution of surface water storage on the Greenland Ice Sheet
	Arnold N.S.; Banwell A.F.; Willis I.C.
发表日期	2014
ISSN	19940416
卷号	8 期号:4
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.
学科领域	drainage; flow modeling; glacial hydrology; lake ecosystem; mass balance; meltwater; runoff; seasonal variation; subglacial environment; Arctic; Greenland; Greenland Ice Sheet
语种	英语
scopus关键词	drainage; flow modeling; glacial hydrology; lake ecosystem; mass balance; meltwater; runoff; seasonal variation; subglacial environment; Arctic; Greenland; Greenland Ice Sheet
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/120093
作者单位	Scott Polar Research Institute, University of Cambridge, Lancefield Road, Cambridge CB2 1ER, United Kingdom
推荐引用方式 GB/T 7714	Arnold N.S.,Banwell A.F.,Willis I.C.. High-resolution modelling of the seasonal evolution of surface water storage on the Greenland Ice Sheet[J],2014,8(4).
APA	Arnold N.S.,Banwell A.F.,&Willis I.C..(2014).High-resolution modelling of the seasonal evolution of surface water storage on the Greenland Ice Sheet.Cryosphere,8(4).
MLA	Arnold N.S.,et al."High-resolution modelling of the seasonal evolution of surface water storage on the Greenland Ice Sheet".Cryosphere 8.4(2014).