1. Department of Atmospheric Sciences University of Washington Seattle WA USA
2. Now at Paul Scherrer Institute Villigen Switzerland
3. Cooperative Institute for Research in Environmental Sciences University of Colorado Boulder Boulder CO USA
4. Department of Chemistry University of Colorado Boulder Boulder CO USA
5. Earth System Research Laboratory, Chemical Sciences Division National Oceanic and Atmospheric Administration Boulder CO USA
6. National Center for Atmospheric Research Boulder CO USA
7. U.S. Environmental Protection Agency Research Triangle NC USA
8. Department of Physics North Carolina Agricultural and Technical State University Greensboro NC USA
9. NOAA‐ISET Center North Carolina Agricultural and Technical State University Greensboro NC USA