1. Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland.
2. Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland.
3. Finnish Meteorological Institute, Erik Palménin aukio 1, 00560 Helsinki, Finland.
4. Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Wien, Austria.
5. CENTRA and FCUL, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
6. Goethe University Frankfurt, Institute for Atmospheric and Environmental Sciences, Altenhöferallee 1, 60438 Frankfurt am Main, Germany.
7. University of Innsbruck, Institute for Ion and Applied Physics, 6020 Innsbruck, Austria.
8. Ionicon GesmbH, Innsbruck, Austria.
9. University of Eastern Finland, Department of Applied Physics, P.O. Box 1627, 70211 Kuopio, Finland.
10. Carnegie Mellon University Center for Atmospheric Particle Studies, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA.
11. Department of Chemistry, University of California, Irvine, Irvine, CA 92697, USA.
12. Department of Chemistry and CIRES, University of Colorado, Boulder, CO 80309 USA.
13. University of Leeds, Leeds LS2 9JT, UK.
14. Aerosol and Haze Laboratory, Beijing University of Chemical Technology, Beijing, China.
15. California Institute of Technology, 210-41, Pasadena, CA 91125, USA.
16. CERN, CH-1211 Geneva, Switzerland.
17. Department of Environmental Science and Analytical Chemistry (ACES) and Bolin Centre for Climate Research, Stockholm University, 10691 Stockholm, Sweden.
18. School of Earth and Environmental Sciences, University of Manchester, Manchester M13 9PL, UK.
19. Joint International Research Laboratory of Atmospheric and Earth System Sciences, Nanjing University, Nanjing, China.
20. Collaborative Innovation Center of Climate Change, Jiangsu Province, China.
21. IDL, Universidade da Beira Interior, Covilhã, Portugal.
22. Laboratory of Environmental Chemistry, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland.
23. Aerodyne Research Inc., 45 Manning Road, Billerica, MA 01821, USA.
24. Aerosol Physics, Faculty of Science, Tampere University of Technology, P.O. Box 692, 33101, Tampere, Finland.
25. Helsinki Institute of Physics, FI-00014 Helsinki, Finland.