气候变化领域集成服务门户(CCPortal): Efficient meltwater drainage through supraglacial streams and rivers on the southwest Greenland ice sheet

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DOI	10.1073/pnas.1413024112
	Efficient meltwater drainage through supraglacial streams and rivers on the southwest Greenland ice sheet
	Smith L.C.; Chu V.W.; Yang K.; Gleason C.J.; Pitcher L.H.; Rennermalm A.K.; Legleiter C.J.; Behar A.E.; Overstreet B.T.; Moustafa S.E.; Tedesco M.; Forster R.R.; LeWinter A.L.; Finnegan D.C.; Sheng Y.; Balog J.
发表日期	2015
ISSN	0027-8424
起始页码	1001
结束页码	1006
卷号	112 期号:4
英文摘要	Thermally incised meltwater channels that flow each summer across melt-prone surfaces of the Greenland ice sheet have received little direct study. We use high-resolution WorldView-1/2 satellite mapping and in situ measurements to characterize supraglacial water storage, drainage pattern, and discharge across 6,812 km2 of southwest Greenland in July 2012, after a record melt event. Efficient surface drainage was routed through 523 high-order stream/river channel networks, all of which terminated in moulins before reaching the ice edge. Low surface water storage (3.6 ± 0.9 cm), negligible impoundment by supraglacial lakes or topographic depressions, and high discharge to moulins (2.54-2.81 cm·d-1) indicate that the surface drainage system conveyed its own storage volume every <2 d to the bed. Moulin discharges mapped inside ∼52% of the source ice watershed for Isortoq, a major proglacial river, totaled ∼41-98% of observed proglacial discharge, highlighting the importance of supraglacial river drainage to true outflow from the ice edge. However, Isortoq discharges tended lower than runoff simulations from the Modèle Atmosphérique Régional (MAR) regional climate model (0.056-0.112 km3·d-1 vs. ∼0.103 km3·d-1), and when integrated over the melt season, totaled just 37-75% of MAR, suggesting nontrivial subglacial water storage even in this melt-prone region of the ice sheet. We conclude that (i) the interior surface of the ice sheet can be efficiently drained under optimal conditions, (ii) that digital elevation models alone cannot fully describe supraglacial drainage and its connection to subglacial systems, and (iii) that predicting outflow from climate models alone, without recognition of subglacial processes, may overestimate true meltwater export from the ice sheet to the ocean.
英文关键词	Greenland ice sheet; Mass balance; Meltwater runoff; Remote sensing; Supraglacial hydrology
语种	英语
scopus关键词	runoff; Article; geology; glacier; Greenland; ice sheet; priority journal; river; stream (river); water supply
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/158914
作者单位	Smith, L.C., Department of Geography, University of California, Los Angeles, CA 90095, United States; Chu, V.W., Department of Geography, University of California, Los Angeles, CA 90095, United States; Yang, K., Department of Geography, University of California, Los Angeles, CA 90095, United States; Gleason, C.J., Department of Geography, University of California, Los Angeles, CA 90095, United States; Pitcher, L.H., Department of Geography, University of California, Los Angeles, CA 90095, United States; Rennermalm, A.K., Department of Geography, Rutgers University, Piscataway, NJ 08854, United States; Legleiter, C.J., Department of Geography, University of Wyoming, Laramie, WY 82071, United States; Behar, A.E., NASA Jet Propulsion Laboratory, Pasadena, CA 91109, United States; Overstreet, B.T., Department of Geography, University of Wyoming, Laramie, WY 82071, United States; Moustafa, S.E., Department of Geography, Rutgers University, Piscataway, NJ 08854, United States; Tedesco, M., Department ...
推荐引用方式 GB/T 7714	Smith L.C.,Chu V.W.,Yang K.,et al. Efficient meltwater drainage through supraglacial streams and rivers on the southwest Greenland ice sheet[J],2015,112(4).
APA	Smith L.C..,Chu V.W..,Yang K..,Gleason C.J..,Pitcher L.H..,...&Balog J..(2015).Efficient meltwater drainage through supraglacial streams and rivers on the southwest Greenland ice sheet.Proceedings of the National Academy of Sciences of the United States of America,112(4).
MLA	Smith L.C.,et al."Efficient meltwater drainage through supraglacial streams and rivers on the southwest Greenland ice sheet".Proceedings of the National Academy of Sciences of the United States of America 112.4(2015).