1. National Centre for Atmospheric Science (NCAS), Department of Chemistry, University of Leicester, UK
2. School of GeoSciences, University of Edinburgh, UK
3. Institute for Advanced Sustainability Studies (IASS), Potsdam, DE
4. Stockholm Environment Institute, Environment Department, University of York, York, UK
5. School of Chemistry, University of Edinburgh, Edinburgh, UK
6. NERC Centre for Ecology and Hydrology, Bush Estate, Penicuik, UK
7. Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, US
8. NOAA Earth System Research Laboratory, Boulder, Colorado, US
9. Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina, US
10. INERIS: Institut National de l’Environnement Industriel et des Risques, Verneuil-en-Halatte, FR
11. Key Laboratory for Atmospheric Chemistry of China Meteorological Administration, Chinese Academy of Meteorological Sciences, Beijing, CN
12. EMEP MSC-W, Norwegian Meteorological Institute, Oslo, NO
13. Department of Space, Earth and Environment, Chalmers Univ. Technology, Gothenburg, SE
14. Institute for Energy and Climate Research (IEK-8), Forschungszentrum Jülich, Jülich, DE
15. Now at Jülich Supercomputing Center, Forschungszentrum Jülich, DE
16. A.S.L. and Associates, Helena, MT, US
17. The University of Maryland School of Public Health, College Park, MD 20742, US
18. School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Johannesburg, ZA
19. Norwegian Institute for Air Research (NILU), Kjeller, NO
20. State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, CN