Methods for measuring water content of snow containing salt

Abstract

Methods for measuring the water content of snow containing salt, which contains liquid water at subzero temperatures, were investigated. Since the temperature of wet snow containing salt is below freezing, a conventional method using a calorimeter underestimates the water content. Two methods were devised: one was to use a calorimeter and add a process of correction for the specific heat from the subzero temperature to 0 °C，and the other was to calculate the water content from the theory of freezing-point depression using only the temperature and salinity of the sample without using a calorimeter. The dataset of water content of snow obtained by both methods agreed well with an error of 3 % for the natural snow samples and artificially salted snow samples. While the former method is rather complex, it is rigorous and applicable for all the salt-contained samples. On the other hand, the latter method is useful because of its simplicity, but it is not applicable when the temperature is above －1 °C．These methods were applied to the measurement of the water content of snow on the Arctic sea ice and on the ice of Saroma-ko lagoon, and it was confirmed that they can be applied to a wide range of conditions.