1. Finnish Meteorological Institute, 00560 Helsinki, Finland
2. Laboratory of Atmospheric Processes and their Impacts, School of Architecture, Civil & Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, 1015, Switzerland
3. Institute of Chemical Engineering Sciences, Foundation for Research and Technology (FORTH/ICE-HT), Hellas, 26504, Patras, Greece
4. Federal Office of Meteorology and Climatology MeteoSwiss, Chemin de l’Aerologie 1, CH-1530 Payerne, Switzerland
5. Department of Technical Physics, University of Eastern Finland, 70211 Kuopio, Finland