DOI: 10.5194/tc-10-371-2016
Scopus记录号: 2-s2.0-84958251046
论文题名: Intercomparison of snow density measurements: Bias, precision, and vertical resolution
作者: Proksch M ; , Rutter N ; , Fierz C ; , Schneebeli M
刊名: Cryosphere
ISSN: 19940416
出版年: 2016
卷: 10, 期: 1 起始页码: 371
结束页码: 384
语种: 英语
英文关键词: alpine environment
; density
; measurement method
; precision
; resolution
; sampling bias
; snow
; threshold
; tomography
; uncertainty analysis
; Davos
; Graubunden
; Switzerland
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). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75187
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: WSL, Institute for Snow and Avalanche Research SLF, Fluëlastrasse 11, Davos Dorf, Switzerland; Institute of Meteorology and Geophysics, University of Innsbruck, Innrain 52, Innsbruck, Austria; Department of Geography, Northumbria University, Newcastle-upon-Tyne, United Kingdom
Recommended Citation:
Proksch M,, Rutter N,, Fierz C,et al. Intercomparison of snow density measurements: Bias, precision, and vertical resolution[J]. Cryosphere,2016-01-01,10(1)