1. Physikalisch-Meteorologisches Observatorium Davos; World Radiation Centre (PMOD/WRC); Dorfstrasse 33, 7260 Davos-Dorf Switzerland
2. Institute of Geography; University of Bern; Hallerstrasse 12, 3012 Bern Switzerland
3. Oeschger Centre for Climate Change Research; Zähringerstrasse 25, 3012 Bern Switzerland