1. Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA;
2. Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington, USA;
3. Atmospheric Sciences Research Center, State University of New York, Albany, New York, USA;
4. Aerodyne Research, Inc, Billerica, Massachusetts, USA;
5. Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland;
6. Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Karlsruhe, Germany;
7. Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA