气候变化领域集成服务门户(CCPortal): Evidence of meltwater retention within the Greenland ice sheet

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DOI	10.5194/tc-7-1433-2013
	Evidence of meltwater retention within the Greenland ice sheet
	Rennermalm A.K.; Smith L.C.; Chu V.W.; Box J.E.; Forster R.R.; Van Den Broeke M.R.; Van As D.; Moustafa S.E.
发表日期	2013
ISSN	19940416
卷号	7 期号:5
英文摘要	Greenland ice sheet mass losses have increased in recent decades with more than half of these attributed to surface meltwater runoff. However, the magnitudes of englacial storage, firn retention, internal refreezing and other hydrologic processes that delay or reduce true water export to the global ocean remain less understood, partly due to a scarcity of in situ measurements. Here, ice sheet surface meltwater runoff and proglacial river discharge between 2008 and 2010 near Kangerlussuaq, southwestern Greenland were used to establish sub- and englacial meltwater storage for a small ice sheet watershed (36-64 km2). This watershed lacks significant potential meltwater storage in firn, surface lakes on the ice sheet and in the proglacial area, and receives limited proglacial precipitation. Thus, ice sheet surface runoff not accounted for by river discharge can reasonably be attributed to retention in sub- and englacial storage. Evidence for meltwater storage within the ice sheet includes (1) characteristic dampened daily river discharge amplitudes relative to ice sheet runoff; (2) three cold-season river discharge anomalies at times with limited ice sheet surface melt, demonstrating that meltwater may be retained up to 1-6 months; (3) annual ice sheet watershed runoff is not balanced by river discharge, and while near water budget closure is possible as much as 54% of melting season ice sheet runoff may not escape to downstream rivers; (4) even the large meltwater retention estimate (54%) is equivalent to less than 1% of the ice sheet volume, which suggests that storage in en- and subglacial cavities and till is plausible. While this study is the first to provide evidence for meltwater retention and delayed release within the Greenland ice sheet, more information is needed to establish how widespread this is along the Greenland ice sheet perimeter. © Author(s) 2013.
学科领域	cryosphere; firn; GRIP; hydrological regime; meltwater; proglacial environment; retention; river discharge; runoff; subglacial environment; till; water storage; watershed; Arctic; Greenland; Greenland Ice Sheet
语种	英语
scopus关键词	cryosphere; firn; GRIP; hydrological regime; meltwater; proglacial environment; retention; river discharge; runoff; subglacial environment; till; water storage; watershed; 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/120258
作者单位	Department of Geography, Rutgers, State University of New Jersey, New Brunswick, NJ, United States; Department of Geography, University of California Los Angeles, Los Angeles, CA, United States; Geological Survey of Denmark and Greenland (GEUS), Copenhagen, Denmark; Department of Geography, University of Utah, Salt Lake City, UT, United States; Institute for Marine and Atmospheric Research, Utrecht University, Utrecht, Netherlands
推荐引用方式 GB/T 7714	Rennermalm A.K.,Smith L.C.,Chu V.W.,et al. Evidence of meltwater retention within the Greenland ice sheet[J],2013,7(5).
APA	Rennermalm A.K..,Smith L.C..,Chu V.W..,Box J.E..,Forster R.R..,...&Moustafa S.E..(2013).Evidence of meltwater retention within the Greenland ice sheet.Cryosphere,7(5).
MLA	Rennermalm A.K.,et al."Evidence of meltwater retention within the Greenland ice sheet".Cryosphere 7.5(2013).