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DOI	10.5194/tcd-9-3581-2015
	Intercomparison of snow density measurements: Bias, precision and spatial resolution
	Proksch M.; Rutter N.; Fierz C.; Schneebeli M.
发表日期	2015
ISSN	19940432
卷号	9 期号:4
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 considered the recent advances in snow measurement methods such as micro-computed tomography (CT). 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 CT and gravimetric methods (density cutters) was 5 to 9 %, with a bias of -5 to 2 %, expressed as percentage of the mean CT density. In the field, the density cutters tend to overestimate (1 to 6 %) densities below and underestimate (1 to 6 %) densities above 296 to 350 kg m-3, respectively, depending on the cutter type. Using the mean per layer of all measurement methods applied in the field (CT, box, wedge and cylinder cutter) and ignoring ice layers, the variation of layer density 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 CT 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 sampling with lower resolution or layer aggregation, is critical when snow density measurements are used as boundary or initial conditions in numerical simulations. © Author(s) 2015.
语种	英语
来源期刊	Cryosphere Discussions
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/119869
作者单位	WSL Institute for Snow and Avalanche Research SLF, Flüelastrasse 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 spatial resolution[J],2015,9(4).
APA	Proksch M.,Rutter N.,Fierz C.,&Schneebeli M..(2015).Intercomparison of snow density measurements: Bias, precision and spatial resolution.Cryosphere Discussions,9(4).
MLA	Proksch M.,et al."Intercomparison of snow density measurements: Bias, precision and spatial resolution".Cryosphere Discussions 9.4(2015).