1. Laboratory for Air Pollution/Environmental Technology, Swiss Federal Laboratories for Materials Science and Technology (Empa), Duebendorf, Switzerland
2. Atmospheric Chemistry Research Group, University of Bristol, Bristol, United Kingdom
3. Department of Basic Sciences and Fundamentals, University of Urbino, Urbino, Italy
4. Hungarian Meteorological Service, Budapest, Hungary
5. Met Office, Exeter, United Kingdom
6. Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland