1. Department of Atmospheric Sciences University of Washington Seattle WA USA
2. Now at Harvard John A. Paulson School of Engineering and Applied Sciences Harvard University Cambridge MA USA
3. Department of Chemistry University of Colorado Boulder Boulder CO USA
4. Cooperative Institute for Research in Environmental Sciences (CIRES) University of Colorado Boulder Boulder CO USA
5. Atmospheric Chemistry Observations and Modeling Laboratory National Center for Atmospheric Research Boulder CO USA
6. Earth Observing Laboratory National Center for Atmospheric Research Boulder CO USA
7. Now at Undergraduate Research Opportunities Center California State University Monterey Bay Seaside CA USA
8. Chemical Sciences Division Earth System Research Laboratory, NOAA Boulder CO USA