1. Institute for Atmospheric and Earth System Research/Physics, University of Helsinki, FI-00014 Helsinki, Finland
2. College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
3. Department of Chemistry and Institute for Atmospheric and Earth System Research (INAR), University of Helsinki, 00014 Helsinki, Finland
4. Aerosol Physics Laboratory, Department of Physics, Tampere University, 33720 Tampere, Finland
5. Karsa Ltd., A. I. Virtasen aukio 1, 00560 Helsinki, Finland