气候变化领域集成服务门户(CCPortal): Top-of-permafrost ground ice indicated by remotely sensed late-season subsidence

CCPortal

DOI	10.5194/tc-15-2041-2021
	Top-of-permafrost ground ice indicated by remotely sensed late-season subsidence
	Zwieback S.; Meyer F.J.
发表日期	2021
ISSN	19940416
起始页码	2041
结束页码	2055
卷号	15 期号:4
英文摘要	Ground ice is foundational to the integrity of Arctic ecosystems and infrastructure. However, we lack finescale ground ice maps across almost the entire Arctic, chiefly because there is no established method for mapping ice-rich permafrost from space. Here, we assess whether remotely sensed late-season subsidence can be used to identify ice-rich permafrost. The idea is that, towards the end of an exceptionally warm summer, the thaw front can penetrate materials that were previously perennially frozen, triggering increased subsidence if they are ice rich. Focusing on northwestern Alaska, we test the idea by comparing the Sentinel-1 Interferometric Synthetic Aperture Radar (InSAR) late-season subsidence observations to permafrost cores and an independently derived ground ice classification.We find that the lateseason subsidence in an exceptionally warm summer was 4-8 cm (5th-95th percentiles) in the ice-rich areas, while it was low in ice-poor areas (-1 to 2 cm; 5th-95th percentiles). The distributions of the late-season subsidence overlapped by 2 %, demonstrating high sensitivity and specificity for identifying top-of-permafrost excess ground ice. The strengths of late-season subsidence include the ease of automation and its applicability to areas that lack conspicuous manifestations of ground ice, as often occurs on hillslopes. One limitation is that it is not sensitive to excess ground ice below the thaw front and thus the total ice content. Late-season subsidence can enhance the automated mapping of permafrost ground ice, complementing existing (predominantly non-automated) approaches based on largely indirect associations with vegetation and periglacial landforms. Thanks to its suitability for mapping ice-rich permafrost, satellite-observed late-season subsidence can make a vital contribution to anticipating terrain instability in the Arctic and sustainably stewarding its ecosystems. © Author(s) 2021.
英文关键词	data set; permafrost; remote sensing; subsidence
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/202462
作者单位	Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, United States
推荐引用方式 GB/T 7714	Zwieback S.,Meyer F.J.. Top-of-permafrost ground ice indicated by remotely sensed late-season subsidence[J],2021,15(4).
APA	Zwieback S.,&Meyer F.J..(2021).Top-of-permafrost ground ice indicated by remotely sensed late-season subsidence.Cryosphere,15(4).
MLA	Zwieback S.,et al."Top-of-permafrost ground ice indicated by remotely sensed late-season subsidence".Cryosphere 15.4(2021).