Trend Analysis of Snow Density and Water Equivalent in the Alpine Region

Snow density is an important property for the characterisation of a snow cover. It is also a key factor for retrieving the snow water equivalent (SWE), which plays a critical role in the water cy- cle in any mountainous region. Both, snow density and SWE are important parameters when as- sessing snow models used e.g. in hydrology or avalanche forecasting. In this study we analyse changes of snow density and SWE measurements from roughly 30 snow sta- tions in the Alps in the last 50 years. The measurement sites are located between 500 and 2600 m asl in four Alpine countries. We show that missing values can be successfully parameterised. The hereby induced error for SWE decreases from about 30% at lowest stations to about 15% only at the highest stations. The long-term time series reveal slightly increasing mid-winter snow density at altitudes be- low 1000 m but decreasing SWE at all altitudes.