A Laboratory Comparison Of Field Techniques For Measurement Of The Liquid Water Fraction Of Snow PDF Download

The amount and distribution of liquid water in a snow cover is important for assessing its mechanical strength, meltwater generation and meltwater transmission. It also has a profound effect on the performance of active and passive remote sensing systems operating in the microwave and millimeter wave regions of the electromagnetic spectrum. New methods of measuring liquid water have been reported that show considerable promise. This report describes tests of measurement equivalence, in which are compared the three absolute methods of freezing calorimetry, alcohol calorimetry and dilution. Also compared are a capacitance snow moisture meter and one of the absolute methods. All comparisons were made in a laboratory coldroom using homogeneous snow with a mass liquid water content that varied from 0 to 14%. The comparisons show that the methods are equivalent and that the experimental errors associated with the measurements are consistent with what is expected from an error analysis of each method. However, the operational achievement of equivalence depends strongly on a variety of factors such as sample size, mixing of snow and working fluid, and operator skill. Keywords: Alcohol calorimetry tests; Dielectric snow moisture meter; Dilution tests; Freezing calorimetry tests; Laboratory tests; Liquid water fraction; Meltwater; Remote sensing; Snow cover; Snow liquid water fraction; Snow measurement; Snowmelt; Wet snow. (EDC).