气候变化领域集成服务门户(CCPortal): Direct measurements of meltwater runoff on the Greenland ice sheet surface

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DOI	10.1073/pnas.1707743114
	Direct measurements of meltwater runoff on the Greenland ice sheet surface
	Smith L.C.; Yang K.; Pitcher L.H.; Overstreet B.T.; Chu V.W.; Rennermalm Å.K.; Ryan J.C.; Cooper M.G.; Gleason C.J.; Tedesco M.; Jeyaratnam J.; Van As D.; Van Den Broeke M.R.; Van De Berg W.J.; Noël B.; Langen P.L.; Cullather R.I.; Zhao B.; Willis M.J.; Hubbard A.; Box J.E.; Jenner B.A.; Behar A.E.
发表日期	2017
ISSN	0027-8424
起始页码	E10622
结束页码	E10631
卷号	114 期号:50
英文摘要	Meltwater runoff from the Greenland ice sheet surface influences surface mass balance (SMB), ice dynamics, and global sea level rise, but is estimated with climate models and thus difficult to validate. We present a way to measure ice surface runoff directly, from hourly in situ supraglacial river discharge measurements and simultaneous high-resolution satellite/drone remote sensing of upstream fluvial catchment area. A first 72-h trial for a 63.1-km2 moulin-terminating internally drained catchment (IDC) on Greenland’s midelevation (1,207–1,381 m above sea level) ablation zone is compared with melt and runoff simulations from HIRHAM5, MAR3.6, RACMO2.3, MERRA-2, and SEB climate/SMB models. Current models cannot reproduce peak discharges or timing of runoff entering moulins but are improved using synthetic unit hydrograph (SUH) theory. Retroactive SUH applications to two older field studies reproduce their findings, signifying that remotely sensed IDC area, shape, and supraglacial river length are useful for predicting delays in peak runoff delivery to moulins. Applying SUH to HIRHAM5, MAR3.6, and RACMO2.3 gridded melt products for 799 surrounding IDCs suggests their terminal moulins receive lower peak discharges, less diurnal variability, and asynchronous runoff timing relative to climate/SMB model output alone. Conversely, large IDCs produce high moulin discharges, even at high elevations where melt rates are low. During this particular field experiment, models overestimated runoff by +21 to +58%, linked to overestimated surface ablation and possible meltwater retention in bare, porous, low-density ice. Direct measurements of ice surface runoff will improve climate/SMB models, and incorporating remotely sensed IDCs will aid coupling of SMB with ice dynamics and subglacial systems.
英文关键词	Climate models; Fluvial catchment; Ice sheet meltwater runoff; Surface mass balance; Surface water hydrology
语种	英语
scopus关键词	Article; density; glacial mass balance; Greenland; ice sheet; measurement; porosity; priority journal; remote sensing; runoff; surface water hydrology; article; catchment; climate; controlled study; drone; field experiment; field study; Greenland; male; river; sea level rise; simulation; snowmelt runoff; surface runoff; surface water hydrology; theoretical study
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/158887
作者单位	Smith, L.C., Department of Geography, University of California, Los Angeles, CA 90095, United States; Yang, K., School of Geographical and Oceanographic Sciences, Nanjing University, Nanjing, 210093, China; Pitcher, L.H., Department of Geography, University of California, Los Angeles, CA 90095, United States; Overstreet, B.T., Department of Geography, University of Wyoming, Laramie, WY 82071, United States; Chu, V.W., Department of Geography, University of California, Santa Barbara, CA 93106, United States; Rennermalm, Å.K., Department of Geography, Rutgers, State University of New Jersey, Piscataway, NJ 08854, United States; Ryan, J.C., Department of Geography, University of California, Los Angeles, CA 90095, United States, Institute at Brown for Environment and Society, Brown University, Providence, RI 02912, United States; Cooper, M.G., Department of Geography, University of California, Los Angeles, CA 90095, United States; Gleason, C.J., Department of Civil and Environmental Engineering, Unive...
推荐引用方式 GB/T 7714	Smith L.C.,Yang K.,Pitcher L.H.,et al. Direct measurements of meltwater runoff on the Greenland ice sheet surface[J],2017,114(50).
APA	Smith L.C..,Yang K..,Pitcher L.H..,Overstreet B.T..,Chu V.W..,...&Behar A.E..(2017).Direct measurements of meltwater runoff on the Greenland ice sheet surface.Proceedings of the National Academy of Sciences of the United States of America,114(50).
MLA	Smith L.C.,et al."Direct measurements of meltwater runoff on the Greenland ice sheet surface".Proceedings of the National Academy of Sciences of the United States of America 114.50(2017).