1. Department of Civil and Environmental Engineering Massachusetts Institute of Technology Cambridge Massachusetts USA
2. Now at State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering Peking University Beijing China
3. CIRES and Department of Chemistry and Biochemistry University of Colorado Boulder Boulder Colorado USA
4. Aerodyne Research, Inc. Billerica Massachusetts USA
5. Department of Environmental Toxicology University of California Davis California USA
6. Key Laboratory for Urban Habitat Environmental Science and Technology, School of Environment and Energy Peking University Shenzhen Graduate School Shenzhen China
7. Leibniz Institute for Tropospheric Research Leipzig Germany
8. School of Engineering and Applied Sciences NHarvard University Cambridge Massachusetts USA
9. Now at Earth Observatory of Singapore Nanyang Technological University Singapore
10. Department of Chemistry University of Toronto Toronto Ontario Canada
11. Air Quality Research Division Environment Canada Toronto Ontario Canada