Analysis and modelling of snow bulk density in the Tyrolean Alps

Abstract

An extensive collection of in-situ snow measurements is used to characterize snow conditions in the entire elevation range of the alpine area of Tyrol, Austria. Regularly observed snow station data are evaluated with respect to mean snow density-time curves of the period 1952-2010. Dependent on the observed snow depth (HS), the snow bulk density (ρ) is statistically modelled for different elevation zones and snow-climate regions. Model improvements allow daily estimates of ρ, and introducing an additional parameter accounting for the decrease of bulk density in relation to new snow data further improved the results. This paper describes the development of an additional model for the glacierized sub-region of the Tyrolean Alps, based on snow course data from the peak snow accumulation period in April/May. The resulting relative errors of the different models range from 13 to 25% for single stations distributed over the entire investigation area and from 5 to 20% for annual snow courses in glacierized catchments. Regression models are most accurate at high elevations and for deep snowpacks. The transferability of the presented models is shown between Austria, Switzerland and Italy.