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DOI	10.5194/tc-10-371-2016
	Intercomparison of snow density measurements: Bias, precision, and vertical resolution
	Proksch M.; Rutter N.; Fierz C.; Schneebeli M.
发表日期	2016
ISSN	19940416
卷号	10 期号:1
英文摘要	Density is a fundamental property of porous media such as snow. A wide range of snow properties and physical processes are linked to density, but few studies have addressed the uncertainty in snow density measurements. No study has yet quantitatively considered the recent advances in snow measurement methods such as micro-computed tomography (μCT) in alpine snow. During the MicroSnow Davos 2014 workshop, different approaches to measure snow density were applied in a controlled laboratory environment and in the field. Overall, the agreement between μCT and gravimetric methods (density cutters) was 5 to 9 %, with a bias of-5 to 2 %, expressed as percentage of the mean μCT density. In the field, density cutters overestimate (1 to 6 %) densities below and underestimate (1 to 6 %) densities above a threshold between 296 to 350 kg m-3, dependent on cutter type. Using the mean density per layer of all measurement methods applied in the field (μCT, box, wedge, and cylinder cutters) and ignoring ice layers, the variation between the methods was 2 to 5% with a bias of-1 to 1 %. In general, our result suggests that snow densities measured by different methods agree within 9 %. However, the density profiles resolved by the measurement methods differed considerably. In particular, the millimeter-scale density variations revealed by the high-resolution μCT contrasted the thick layers with sharp boundaries introduced by the observer. In this respect, the unresolved variation, i.e., the density variation within a layer which is lost by lower resolution sampling or layer aggregation, is critical when snow density measurements are used in numerical simulations. © 2016 Author(s).
学科领域	alpine environment; density; measurement method; precision; resolution; sampling bias; snow; threshold; tomography; uncertainty analysis; Davos; Graubunden; Switzerland
语种	英语
scopus关键词	alpine environment; density; measurement method; precision; resolution; sampling bias; snow; threshold; tomography; uncertainty analysis; Davos; Graubunden; Switzerland
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/119703
作者单位	WSL, Institute for Snow and Avalanche Research SLF, Fluëlastrasse 11, Davos Dorf, 7260, Switzerland; Institute of Meteorology and Geophysics, University of Innsbruck, Innrain 52, Innsbruck, 6020, Austria; Department of Geography, Northumbria University, Newcastle-upon-Tyne, United Kingdom
推荐引用方式 GB/T 7714	Proksch M.,Rutter N.,Fierz C.,et al. Intercomparison of snow density measurements: Bias, precision, and vertical resolution[J],2016,10(1).
APA	Proksch M.,Rutter N.,Fierz C.,&Schneebeli M..(2016).Intercomparison of snow density measurements: Bias, precision, and vertical resolution.Cryosphere,10(1).
MLA	Proksch M.,et al."Intercomparison of snow density measurements: Bias, precision, and vertical resolution".Cryosphere 10.1(2016).