气候变化领域集成服务门户(CCPortal): Self-affine subglacial roughness: Consequences for radar scattering and basal water discrimination in northern Greenland

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DOI	10.5194/tc-11-1247-2017
	Self-affine subglacial roughness: Consequences for radar scattering and basal water discrimination in northern Greenland
	Jordan T.M.; Cooper M.A.; Schroeder D.M.; Williams C.N.; Paden J.D.; Siegert M.J.; Bamber J.L.
发表日期	2017
ISSN	19940416
卷号	11 期号:3
英文摘要	Subglacial roughness can be determined at a variety of length scales from radio-echo sounding (RES) data either via statistical analysis of topography or inferred from basal radar scattering. Past studies have demonstrated that subglacial terrain exhibits self-affine (power law) roughness scaling behaviour, but existing radar scattering models do not take this into account. Here, using RES data from northern Greenland, we introduce a self-affine statistical framework that enables a consistent integration of topographicscale roughness with the electromagnetic theory of radar scattering. We demonstrate that the degree of radar scattering, quantified using the waveform abruptness (pulse peakiness), is topographically controlled by the Hurst (roughness power law) exponent. Notably, specular bed reflections are associated with a lower Hurst exponent, with diffuse scattering associated with a higher Hurst exponent. Abrupt waveforms (specular reflections) have previously been used as a RES diagnostic for basal water, and to test this assumption we compare our radar scattering map with a recent prediction for the basal thermal state. We demonstrate that the majority of thawed regions (above pressure melting point) exhibit a diffuse scattering signature, which is in contradiction to the prior approach. Self-affine statistics provide a generalised model for subglacial terrain and can improve our understanding of the relationship between basal properties and ice-sheet dynamics. © Author(s) 2017. CC Attribution 3.0 License.
学科领域	echo sounding; electromagnetic survey; ice sheet; melting; radar; radar imagery; statistical analysis; subglacial environment; terrain; Arctic; Greenland
语种	英语
scopus关键词	echo sounding; electromagnetic survey; ice sheet; melting; radar; radar imagery; statistical analysis; subglacial environment; terrain; Arctic; Greenland
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/119394
作者单位	Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, United Kingdom; Department of Geophysics, Stanford University, Stanford, CA, United States; Center for Remote Sensing of Ice Sheets, University of Kansas, Lawrence, KS, United States; Grantham Institute, Department of Earth Science and Engineering, Imperial College, London, United Kingdom
推荐引用方式 GB/T 7714	Jordan T.M.,Cooper M.A.,Schroeder D.M.,et al. Self-affine subglacial roughness: Consequences for radar scattering and basal water discrimination in northern Greenland[J],2017,11(3).
APA	Jordan T.M..,Cooper M.A..,Schroeder D.M..,Williams C.N..,Paden J.D..,...&Bamber J.L..(2017).Self-affine subglacial roughness: Consequences for radar scattering and basal water discrimination in northern Greenland.Cryosphere,11(3).
MLA	Jordan T.M.,et al."Self-affine subglacial roughness: Consequences for radar scattering and basal water discrimination in northern Greenland".Cryosphere 11.3(2017).