1. Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, 00014 Helsinki, Finland
2. Institute of Ion Physics and Applied Physics, University of Innsbruck, 6020 Innsbruck, Austria
3. Institute for Atmospheric and Environmental Sciences, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
4. Center for Atmospheric Particle Studies, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
5. Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
6. CENTRA and Faculdade de Ciências da Universidade de Lisboa, 1749-016 Campo Grande, Lisboa, Portugal
7. Leibniz Institute for Tropospheric Research, Permoserstrasse 15, 04318 Leipzig, Germany
8. Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, 76344 Karlsruhe, Germany
9. Helsinki Institute of Physics, University of Helsinki, 00014 Helsinki, Finland
10. Department of Chemistry and Cooperative Institute for Research in the Environmental Sciences, University of Colorado Boulder, Boulder, Colorado 80309, United States
11. CERN, the European Organization for Nuclear Research, CH-1211 Geneva 23, Switzerland
12. Aerosol Physics Laboratory, Physics Unit, Faculty of Engineering and Natural Sciences, Tampere University, 33014 Tampere, Finland
13. Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
14. Aerodyne Research, Inc., Billerica, Massachusetts 01821, United States
15. Atmospheric and Oceanic Sciences, Princeton University, Princeton, New Jersey 08540, United States
16. Department of Physics, University of Genoa & INFN, 16146 Genoa, Italy
17. Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
18. Department of Atmospheric and Oceanic Sciences, University of Colorado Boulder, Boulder, Colorado 80309, United States
19. P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 119991 Moscow, Russia
20. Finnish Meteorological Institute, Erik Palmenin aukio 1, 00560 Helsinki, Finland
21. Division of Nuclear Physics, Lund University, 22100 Lund, Sweden
22. Department of Applied Physics, University of Eastern Finland, 70211 Kuopio, Finland
23. School of Marine Sciences, Sun Yat-sen University, 519082 Zhuhai, China
24. Institute Infante Dom Luíz, University of Beira Interior, 6200-001 Covilhã, Portugal
25. Joint International Research Laboratory of Atmospheric and Earth System Sciences, School of Atmospheric Sciences, Nanjing University, 210023 Nanjing, China
26. Aerosol and Haze Laboratory, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, 100029 Beijing, China
27. Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
28. Department of Engineering and Public Policy, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States