1. WSL Institute for Snow and Avalanche Research SLF; Davos Dorf Switzerland
2. Department of Geography; Ludwig-Maximilians-Universität München; Munich Germany
3. Institute of Environmental Physics; University of Heidelberg; Heidelberg Germany
4. Alfred-Wegener-Institut Helmholtz Zentrum für Polar- und Meeresforschung; Bremerhaven and Universität Bremen; Bremen Germany