1. Institute for Marine and Atmospheric Research Utrecht (IMAU); Utrecht The Netherlands
2. Department of Meteorology and Air Quality at Wageningen University; Wageningen The Netherlands
3. Max-Planck-Institut für Chemie, Air Chemistry Division; Mainz Germany
4. Department of Air Quality and Climate Research at the Energy Research Centre of the Netherlands (ECN); Petten The Netherlands
5. School of Chemistry; University of Bristol; Bristol UK
6. Centre for Australian Weather and Climate Research; CSIRO Marine and Atmospheric Research; Aspendale Victoria Australia
7. School of Earth and Atmospheric Sciences; Georgia Institute of Technology; Atlanta GA USA
8. Laboratoire des Sciences du Climat et de l'Environnement (LSCE); Gif-sur-Yvette France
9. Max-Planck Institut für Biogeochemie; Jena Germany
10. Institut für Meteorologie und Geophysik; Goethe-Universität Frankfurt; Frankfurt Germany
11. Department of Earth Sciences; Royal Holloway, University of London; Egham UK
12. Empa; Swiss Federal Institute for Materials Science and Technology, Laboratory for Air Pollution/Environmental Technology; Duebendorf Switzerland
13. Institut für Umweltphysik; Heidelberg Universität; Heidelberg Germany
14. School of Environmental Sciences; University of East Anglia; Norwich UK