气候变化领域集成服务门户(CCPortal): Ice velocity of Jakobshavn Isbræ, Petermann Glacier, Nioghalvfjerdsfjorden, and Zachariæ Isstrøm, 2015-2017, from Sentinel 1-a/b SAR imagery

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DOI	10.5194/tc-12-2087-2018
	Ice velocity of Jakobshavn Isbræ, Petermann Glacier, Nioghalvfjerdsfjorden, and Zachariæ Isstrøm, 2015-2017, from Sentinel 1-a/b SAR imagery
	Lemos A.; Shepherd A.; McMillan M.; Hogg A.E.; Hatton E.; Joughin I.
发表日期	2018
ISSN	19940416
卷号	12 期号:6
英文摘要	Systematically monitoring Greenland's outlet glaciers is central to understanding the timescales over which their flow and sea level contributions evolve. In this study we use data from the new Sentinel-1a/b satellite constellation to generate 187 velocity maps, covering four key outlet glaciers in Greenland: Jakobshavn Isbræ, Petermann Glacier, Nioghalvfjerdsfjorden, and Zachariæ Isstrøm. These data provide a new high temporal resolution record (6-day averaged solutions) of each glacier's evolution since 2014, and resolve recent seasonal speedup periods and inter-annual changes in Greenland outlet glacier speed with an estimated certainty of 10%. We find that since 2012, Jakobshavn Isbræ has been decelerating, and now flows approximately 1250g yr-1 (10%), slower than 5 years previously, thus reversing an increasing trend in ice velocity that has persisted during the last decade. Despite this, we show that seasonal variability in ice velocity remains significant: up to 750g yr-1 (14%) at a distance of 12 km inland of the terminus. We also use our new dataset to estimate the duration of speedup periods (80-95 days) and to demonstrate a strong relationship between ice front position and ice flow at Jakobshavn Isbræ, with increases in speed of 1800g yr-1 in response to 1 km of retreat. Elsewhere, we record significant seasonal changes in flow of up to 25% (2015) and 18% (2016) at Petermann Glacier and Zachariæ Isstrøm, respectively. This study provides a first demonstration of the capacity of a new era of operational radar satellites to provide frequent and timely monitoring of ice sheet flow, and to better resolve the timescales over which glacier dynamics evolve. © 2018 Author(s).
学科领域	annual variation; glacier dynamics; ice flow; ice sheet; satellite constellation; sea level change; Sentinel; synthetic aperture radar; trend analysis; Arctic; Greenland; Jakobshavn Glacier; Nioghalvfjerdsfjorden Glacier; Petermann Glacier
语种	英语
scopus关键词	annual variation; glacier dynamics; ice flow; ice sheet; satellite constellation; sea level change; Sentinel; synthetic aperture radar; trend analysis; Arctic; Greenland; Jakobshavn Glacier; Nioghalvfjerdsfjorden Glacier; Petermann Glacier
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/119125
作者单位	Centre for Polar Observation and Modelling, University of Leeds, Leeds, United Kingdom; Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA, United States
推荐引用方式 GB/T 7714	Lemos A.,Shepherd A.,McMillan M.,et al. Ice velocity of Jakobshavn Isbræ, Petermann Glacier, Nioghalvfjerdsfjorden, and Zachariæ Isstrøm, 2015-2017, from Sentinel 1-a/b SAR imagery[J],2018,12(6).
APA	Lemos A.,Shepherd A.,McMillan M.,Hogg A.E.,Hatton E.,&Joughin I..(2018).Ice velocity of Jakobshavn Isbræ, Petermann Glacier, Nioghalvfjerdsfjorden, and Zachariæ Isstrøm, 2015-2017, from Sentinel 1-a/b SAR imagery.Cryosphere,12(6).
MLA	Lemos A.,et al."Ice velocity of Jakobshavn Isbræ, Petermann Glacier, Nioghalvfjerdsfjorden, and Zachariæ Isstrøm, 2015-2017, from Sentinel 1-a/b SAR imagery".Cryosphere 12.6(2018).