气候变化领域集成服务门户(CCPortal): Surface velocity of the Northeast Greenland Ice Stream (NEGIS): Assessment of interior velocities derived from satellite data by GPS

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DOI	10.5194/tc-14-3487-2020
	Surface velocity of the Northeast Greenland Ice Stream (NEGIS): Assessment of interior velocities derived from satellite data by GPS
	Hvidberg C.S.; Grinsted A.; Dahl-Jensen D.; Khan S.A.; Kusk A.; Andersen J.K.; Neckel N.; Solgaard A.; Karlsson N.B.; Kjar H.A.; Vallelonga P.
发表日期	2020
ISSN	19940416
起始页码	3487
结束页码	3502
卷号	14 期号:10
英文摘要	The Northeast Greenland Ice Stream (NEGIS) extends around 600 km upstream from the coast to its onset near the ice divide in interior Greenland. Several maps of surface velocity and topography of interior Greenland exist, but their accuracy is not well constrained by in situ observations. Here we present the results from a GPS mapping of surface velocity in an area located approximately 150 km from the ice divide near the East Greenland Ice-core Project (EastGRIP) deep-drilling site. A GPS strain net consisting of 63 poles was established and observed over the years 2015-2019. The strain net covers an area of 35 km by 40 km, including both shear margins. The ice flows with a uniform surface speed of approximately 55ma1 within a central flow band with longitudinal and transverse strain rates on the order of 104 a1 and increasing by an order of magnitude in the shear margins. We compare the GPS results to the Arctic Digital Elevation Model and a list of satellite-derived surface velocity products in order to evaluate these products. For each velocity product, we determine the bias in and precision of the velocity compared to the GPS observations, as well as the smoothing of the velocity products needed to obtain optimal precision. The best products have a bias and a precision of 0:5ma1. We combine the GPS results with satellite-derived products and show that organized patterns in flow and topography emerge in NEGIS when the surface velocity exceeds approximately 55ma1 and are related to bedrock topography. © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License.
英文关键词	bedrock; digital elevation model; glacial hydrology; GPS; ice core; satellite data; shear strength; smoothing; topography; velocity profile; Arctic; East Greenland; Greenland; Greenland Ice Sheet
语种	英语
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/202110
作者单位	Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark; Dtu Space, Technical University of Denmark, Kongens Lyngby, Denmark; Alfred-Wegener-Institut, Helmholtz-Zentrum för Polar-und Meeresforschung, Bremerhaven, Germany; Geological Survey of Denmark and Greenland, Copenhagen, Denmark
推荐引用方式 GB/T 7714	Hvidberg C.S.,Grinsted A.,Dahl-Jensen D.,et al. Surface velocity of the Northeast Greenland Ice Stream (NEGIS): Assessment of interior velocities derived from satellite data by GPS[J],2020,14(10).
APA	Hvidberg C.S..,Grinsted A..,Dahl-Jensen D..,Khan S.A..,Kusk A..,...&Vallelonga P..(2020).Surface velocity of the Northeast Greenland Ice Stream (NEGIS): Assessment of interior velocities derived from satellite data by GPS.Cryosphere,14(10).
MLA	Hvidberg C.S.,et al."Surface velocity of the Northeast Greenland Ice Stream (NEGIS): Assessment of interior velocities derived from satellite data by GPS".Cryosphere 14.10(2020).