Performance of snow density measurement systems in snow stratigraphies

Abstract. Gravimetric and dielectric permittivity measuring systems are applied to measure snow density, but few studies have addressed differences between the two measurement systems under complex snowpack conditions. A field experiment was conducted to measure snow density using the two measurement systems in different stratigraphical layers consisting of fragmented precipitation particles (DF), faceted crystals particles (FC), depth hoar (DH) and melt forms (MF), and the performance of measurement systems were analyzed and compared. The results showed that the measured density from the gravimetric measurement system was significantly higher than from the dielectric permittivity measurement system. The precision and accuracy of the gravimetric measurement system was higher than that of the dielectric permittivity measurement system in the DF, FC and DH layers, but the precision and accuracy of two measurement systems were similar in the MF layers. By comparing the precision and accuracy as well as merits and drawbacks of the two measurement systems, it was concluded that using gravimetric measurement system during dry snow and dielectric permittivity measurement system during wet snow will help surveyors obtain more reliable data. Furthermore, the study provided an approach which will facilitate the integration of the data obtained from different studies with different measurement systems into global databases.