气候变化领域集成服务门户(CCPortal): Measuring the specific surface area of wet snow using 1310 nm reflectance

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DOI	10.5194/tc-8-1139-2014
	Measuring the specific surface area of wet snow using 1310 nm reflectance
	Gallet J.-C.; Domine F.; Dumont M.
发表日期	2014
ISSN	19940416
卷号	8 期号:4
英文摘要	The specific surface area (SSA) of snow can be used as an objective measurement of grain size and is therefore a central variable to describe snow physical properties such as albedo. Snow SSA can now be easily measured in the field using optical methods based on infrared reflectance. However, existing optical methods have only been validated for dry snow. Here we test the possibility to use the DUFISSS instrument, based on the measurement of the 1310 nm reflectance of snow with an integrating sphere, to measure the SSA of wet snow. We perform cold room experiments where we measure the SSA of a wet snow sample, freeze it and measure it again, to quantify the difference in reflectance between frozen and wet snow. We study snow samples in the SSA range 12-37 m2 kgĝ̂'1 and in the mass liquid water content (LWC) range 5-32%. We conclude that the SSA of wet snow can be obtained from the measurement of its 1310 nm reflectance using three simple steps. In most cases, the SSA thus obtained is less than 10 {%} different from the value that would have been obtained if the sample had been considered dry, so that the three simple steps constitute a minor correction. We also run two optical models to interpret the results, but no model reproduces correctly the water-ice distribution in wet snow, so that their predictions of wet snow reflectance are imperfect. The correction on the determination of wet snow SSA using the DUFISSS instrument gives an overall uncertainty better than 11%, even if the LWC is unknown. If SSA is expressed as a surface to volume ratio (e.g., in mmĝ̂'1), the uncertainty is then 13% because of additional uncertainties in the determination of the volume of ice and water when the LWC is unknown. © Author(s) 2014. CC Attribution 3.0 License.
学科领域	albedo; grain size; optical method; prediction; reflectance; snow; surface area; volume
语种	英语
scopus关键词	albedo; grain size; optical method; prediction; reflectance; snow; surface area; volume
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/120094
作者单位	Norwegian Polar Institute, Troms, Norway; Takuvik Joint International Laboratory, Université Laval (Canada) and CNRS-INSU (France), Pavillon Alexandre Vachon, 1045 avenue de La Médecine, Quebec, QC, G1V 0A6, Canada; Department of Chemistry, Université Laval, Quebec, QC, Canada; Météo-France -CNRS, CNRM-GAME UMR3589, CEN, Grenoble, France
推荐引用方式 GB/T 7714	Gallet J.-C.,Domine F.,Dumont M.. Measuring the specific surface area of wet snow using 1310 nm reflectance[J],2014,8(4).
APA	Gallet J.-C.,Domine F.,&Dumont M..(2014).Measuring the specific surface area of wet snow using 1310 nm reflectance.Cryosphere,8(4).
MLA	Gallet J.-C.,et al."Measuring the specific surface area of wet snow using 1310 nm reflectance".Cryosphere 8.4(2014).