DOI: 10.5194/tc-11-1247-2017
Scopus记录号: 2-s2.0-85019891073
论文题名: Self-affine subglacial roughness: Consequences for radar scattering and basal water discrimination in northern Greenland
作者: Jordan T ; M ; , Cooper M ; A ; , Schroeder D ; M ; , Williams C ; N ; , Paden J ; D ; , Siegert M ; J ; , Bamber J ; L
刊名: Cryosphere
ISSN: 19940416
出版年: 2017
卷: 11, 期: 3 起始页码: 1247
结束页码: 1264
语种: 英语
英文关键词: echo sounding
; electromagnetic survey
; ice sheet
; melting
; radar
; radar imagery
; statistical analysis
; subglacial environment
; terrain
; Arctic
; Greenland
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. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75552
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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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
Recommended Citation:
Jordan T,M,, Cooper M,et al. Self-affine subglacial roughness: Consequences for radar scattering and basal water discrimination in northern Greenland[J]. Cryosphere,2017-01-01,11(3)