1. Department of Physics University of Toronto Toronto Ontario Canada
2. Department of Civil and Environmental Engineering Carleton University Ottawa Ontario Canada
3. School of Earth and Space Sciences University of Science and Technology of China Hefei Anhui China
4. Department of Mechanical Engineering University of Colorado at Boulder Boulder CO USA
5. Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research Boulder CO USA
6. Department of Physics & Engineering Physics University of Saskatchewan Saskatoon Saskatchewan Canada
7. Air Quality Research Division Environment and Climate Change Canada Toronto Ontario Canada