1. Department of Environmental Systems ScienceETH Zurich Zurich Switzerland
2. Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) Birmensdorf Switzerland
3. Faculty of Environment and Natural ResourcesUniversity of Freiburg Freiburg im Breisgau Germany
4. Schmid College of Science and TechnologyChapman University Orange CA USA
5. Department of Earth and Planetary ScienceUniversity of California Berkeley CA USA