1. Norwegian Polar Institute, Fram Centre; Tromsø Norway
2. DTU Space, Technical University of Denmark, National Space Institute; Lyngby Denmark
3. University of Bremen, Institute of Environmental Physics; Bremen Germany
4. U.S. Army Cold Regions and Engineering Laboratory; Alaska, Fort Wainwright; Alaska USA
5. Alfred Wegener Institute; Bremerhaven Germany
6. Cooperative Institute for Research in the Atmosphere; Colorado State University; Fort Collins Colorado USA