1. Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
2. Paul Scherrer Institut, Villigen 5232, Switzerland
3. Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado 80305, United States
4. Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, Colorado 80309, United States
5. Applied Physics Program, University of Michigan, Ann Arbor, Michigan 48109, United States
6. Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
7. Department of Meteorology and Atmospheric Science, The Pennsylvania State University, University Park, Pennsylvania 16802 United States
8. Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, Michigan 48109, United States