1. Institute of Environmental Assessment and Water Research; Barcelona Spain
2. Department of Chemistry and Biochemistry; University of Colorado Boulder; Boulder Colorado USA
3. Cooperative Institute for Research in Environmental Sciences; Boulder Colorado USA
4. Earth Sciences Department; Barcelona Supercomputing Center-Centro Nacional de Supercomputacion; Barcelona Spain
5. Department of Atmospheric and Oceanic Sciences; University of Colorado Boulder; Boulder Colorado USA
6. Now at Tofwerk AG; Thun Switzerland
7. Remote Sensing Laboratory, Signal Theory and Communications Department; Technical University of Catalonia; Barcelona Spain
8. Institute for Space Studies of Catalonia - Aerospace and Research Center; Technical University of Catalonia; Barcelona Spain
9. Laboratory of Atmospheric Chemistry; Paul Scherrer Institute; Villigen Switzerland
10. Now at Department of Atmospheric Sciences; University of Washington; Seattle Washington USA
11. Environmental Modeling Laboratory; Technical University of Catalonia; Barcelona Spain
12. NILU - Norwegian Institute for Air Research; Kjeller Norway
13. CSIC, Global Ecology Unit CREAF-CEAB-UAB; Cerdanyola del Vallès Spain
14. Now at Atmospheric Chemistry Division; National Center for Atmospheric Research; Boulder Colorado USA
15. CREAF; Cerdanyola del Vallès Spain
16. Research Centre on Energy, Environment and Technology CIEMAT; Madrid Spain
17. Centre for Ecology & Hydrology (Edinburgh); Penicuik UK
18. Institut für Ionenphysik und Angewandte Physik; Universitåt Innsbruck; Innsbruck Austria
19. Now at Department of Physical Sciences, Division of Atmospheric Sciences; University of Helsinki; Helsinki Finland
20. Ionicon Analytik; Innsbruck Austria
21. Atmospheric Physics Group of the University of Barcelona; Barcelona Spain
22. School of Chemical and Biomolecular Engineering and School of Earth and Atmospheric Sciences; Georgia Institute of Technology, Atlanta; Georgia USA
23. Aerodyne Research, Inc.; Billerica Massachusetts USA
24. Department of Chemistry and Biochemistry; University of Bern; Bern Switzerland
25. Oeschger Centre for Climate Change Research; University of Bern; Bern Switzerland