1. Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, 00014 Helsinki, Finland
2. Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science & Engineering, Fudan University, 200438 Shanghai, China
3. Karsa Ltd., A. I. Virtasen aukio 1, 00560 Helsinki, Finland
4. Faculty of Engineering and Natural Sciences, Tampere University, 33720 Tampere, Finland
5. Aerodyne Research, Inc., 45 Manning Road, Billerica, Massachusetts 01821, United States