1. School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
2. Department of Environmental Health & Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
3. Department of Chemistry, University of California, Irvine, California, 92697, United States
4. Geophysical Institute and Department of Chemistry & Biochemistry, University of Alaska Fairbanks, Fairbanks, Alaska 99775, United States
5. Laboratory of Atmospheric Processes and their Impacts (LAPI), School of Architecture, Civil & Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland
6. Center for Studies of Air Quality and Climate Change, Institute of Chemical Engineering Sciences, Foundation for Research and Technology, Patras, Hellas 26504, Greece