气候变化领域集成服务门户(CCPortal): An ice-sheet-wide framework for englacial attenuation from ice-penetrating radar data

CCPortal

DOI	10.5194/tc-10-1547-2016
	An ice-sheet-wide framework for englacial attenuation from ice-penetrating radar data
	Jordan T.M.; Bamber J.L.; Williams C.N.; Paden J.D.; Siegert M.J.; Huybrechts P.; Gagliardini O.; Gillet-Chaulet F.
发表日期	2016
ISSN	19940416
卷号	10 期号:4
英文摘要	Radar inference of the bulk properties of glacier beds, most notably identifying basal melting, is, in general, derived from the basal reflection coefficient. On the scale of an ice sheet, unambiguous determination of basal reflection is primarily limited by uncertainty in the englacial attenuation of the radio wave, which is an Arrhenius function of temperature. Existing bed-returned power algorithms for deriving attenuation assume that the attenuation rate is regionally constant, which is not feasible at an ice-sheet-wide scale. Here we introduce a new semi-empirical framework for deriving englacial attenuation, and, to demonstrate its efficacy, we apply it to the Greenland Ice Sheet. A central feature is the use of a prior Arrhenius temperature model to estimate the spatial variation in englacial attenuation as a first guess input for the radar algorithm. We demonstrate regions of solution convergence for two input temperature fields and for independently analysed field campaigns. The coverage achieved is a trade-off with uncertainty and we propose that the algorithm can be "tuned" for discrimination of basal melt (attenuation loss uncertainty ∼ 5 dB). This is supported by our physically realistic ( ∼20 dB) range for the basal reflection coefficient. Finally, we show that the attenuation solution can be used to predict the temperature bias of thermomechanical ice sheet models and is in agreement with known model temperature biases at the Dye 3 ice core. © 2016 Author(s).
学科领域	algorithm; basal melting; englacial process; ground penetrating radar; ice core; ice sheet; radio wave; spatial variation; temperature effect; thermomechanics; trade-off; Arctic; Greenland; Greenland Ice Sheet
语种	英语
scopus关键词	algorithm; basal melting; englacial process; ground penetrating radar; ice core; ice sheet; radio wave; spatial variation; temperature effect; thermomechanics; trade-off; Arctic; Greenland; Greenland Ice Sheet
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/119614
作者单位	Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, United Kingdom; Center for Remote Sensing of Ice Sheets, University of Kansas, Lawrence, United States; Grantham Institute and Earth Science and Engineering, Imperial College, University of London, London, United Kingdom; Earth System Science and Departement Geografie, Vrije Universiteit Brussel, Brussels, Belgium; Le Laboratoire de Glaciologie et Geophysique de l'Environnement, University Grenoble Alpes, Grenoble, France; Le Laboratoire de Glaciologie et Geophysique de l'Environnement, Centre National de la Recherche Scientifique, Grenoble, France
推荐引用方式 GB/T 7714	Jordan T.M.,Bamber J.L.,Williams C.N.,et al. An ice-sheet-wide framework for englacial attenuation from ice-penetrating radar data[J],2016,10(4).
APA	Jordan T.M..,Bamber J.L..,Williams C.N..,Paden J.D..,Siegert M.J..,...&Gillet-Chaulet F..(2016).An ice-sheet-wide framework for englacial attenuation from ice-penetrating radar data.Cryosphere,10(4).
MLA	Jordan T.M.,et al."An ice-sheet-wide framework for englacial attenuation from ice-penetrating radar data".Cryosphere 10.4(2016).