1. Department of Geosciences, University of Oslo, PO Box 1022, Blindern, 0315 Oslo, Norway
2. Center for International Climate and Environmental Research – Oslo, Norway
3. Norwegian Institute for Air Research, Norway
4. Met Office, Exeter, UK
5. Meteo-France (CNRM/GMEI), France
6. NASA Goddard Institute for Space Studies, New York, USA
7. Laboratoire d’Optique Atmosphérique, Centre National de la Recherche Scientifique, Université des Sciences et Technologies de Lille, Villeneuve d’Ascq, France