1. Department of Meteorology and Bolin Centre for Climate Research; Stockholm University; Stockholm Sweden
2. Department of Physics and Technology; UiT Arctic University of Norway; Tromsø Norway
3. Max-Planck-Institute for Meteorology; Hamburg Germany
4. National Snow and Ice Data Center, Cooperative Institute for Research in Environmental Sciences; University of Colorado Boulder; Boulder Colorado USA
5. Centre for Polar Observation and Modelling, Earth Sciences/Department of Space and Climate Physics (MSSL); University College London; London UK
6. Earth System Science Interdisciplinary Center; University of Maryland; College Park Maryland USA