Snow instability in a changing climate


Alec van Herwijnen


Jürg Schweizer


Stephanie Isabelle Mayer
Alec van Herwijnen

The seasonal snowpack is very sensitive to climate change. Rising air temperatures lead to a reduction of mean snow depths and snow cover duration in Alpine regions. However, less snow does not imply less avalanches. The formation of weak layers (fragile layers within the snowpack necessary for avalanche formation) is often associated with a shallow snowpack and/or early-season rain crusts. In this project, we assess the influence of climate change on avalanches by modeling future snow instability for selected representative sites in Switzerland. By analyzing existing data on avalanche activity, we establish methods to describe the degree of instability over entire winter seasons. Snow stratigraphy is then modeled by driving the detailed snow cover model SNOWPACK with downscaled climate projections and trends for future avalanche activity are assessed.