气候变化领域集成服务门户(CCPortal): The Presence and Widespread Distribution of Dark Sediment in Greenland Ice Sheet Supraglacial Streams Implies Substantial Impact of Microbial Communities on Sediment Deposition and Albedo

CCPortal

DOI	10.1029/2020GL088444
	The Presence and Widespread Distribution of Dark Sediment in Greenland Ice Sheet Supraglacial Streams Implies Substantial Impact of Microbial Communities on Sediment Deposition and Albedo
	Leidman S.Z.; Rennermalm Å.K.; Muthyala R.; Guo Q.; Overeem I.
发表日期	2021
ISSN	0094-8276
卷号	48 期号:1
英文摘要	Melting on the Greenland Ice Sheet leads to extensive supraglacial stream networks. These streams accumulate low-albedo sediments disproportionately contribute to melting. Studies analyzing supraglacial sediment distribution and hydrodynamic properties are rare. Here, we examine a 130-m supraglacial stream reach in southwest Greenland using drone imagery, bathymetry, and hydrology measurements from 2017. Sediment covered 24% of the channel and had a mass-median diameter of 0.027 mm. We applied calculations of critical Shields stress to determine the minimum water depth needed to initiate sediment movement. In order for theoretical critical water depths to match observed depths, sediment grains would need to be 2.48 mm (near the grain size for cryoconite granules) indicating that microbial growth within sediment caused extensive flocculation. Without flocculation, sediment would flush out of floodplains and supraglacial streams would have significantly higher albedos. Supraglacial stream albedo might therefore be sensitive to changing stream chemistry, temperature, and meltwater supply. © 2020. The Authors.
英文关键词	Flocculation; Glaciers; Hydrographic surveys; Melting; Ostwald ripening; Solar radiation; Greenland Ice Sheet; Hydrodynamic properties; Mass median diameters; Microbial communities; Microbial growth; Sediment deposition; Sediment distribution; Sediment movement; Sediments
语种	英语
来源期刊	Geophysical Research Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/169236
作者单位	Department of Geography, Rutgers, The State University of New Jersey, Piscataway, NJ, United States; Department of Civil and Environmental Engineering, Rutgers, The State University of New Jersey, Piscataway, NJ, United States; INSTAAR, University of Colorado at Boulder, Boulder, CO, United States; Department of Geological Sciences, University of Colorado at Boulder, Boulder, CO, United States
推荐引用方式 GB/T 7714	Leidman S.Z.,Rennermalm Å.K.,Muthyala R.,et al. The Presence and Widespread Distribution of Dark Sediment in Greenland Ice Sheet Supraglacial Streams Implies Substantial Impact of Microbial Communities on Sediment Deposition and Albedo[J],2021,48(1).
APA	Leidman S.Z.,Rennermalm Å.K.,Muthyala R.,Guo Q.,&Overeem I..(2021).The Presence and Widespread Distribution of Dark Sediment in Greenland Ice Sheet Supraglacial Streams Implies Substantial Impact of Microbial Communities on Sediment Deposition and Albedo.Geophysical Research Letters,48(1).
MLA	Leidman S.Z.,et al."The Presence and Widespread Distribution of Dark Sediment in Greenland Ice Sheet Supraglacial Streams Implies Substantial Impact of Microbial Communities on Sediment Deposition and Albedo".Geophysical Research Letters 48.1(2021).