1. Atmospheric Chemistry, Observations and Modeling LaboratoryNational Center for Atmospheric Research Boulder CO USA
2. Climate and Global Dynamics LaboratoryNational Center for Atmospheric Research Boulder CO USA
3. Atmospheric Sciences and Global Change DivisionPacific Northwest National Laboratory Richland WA USA
4. Cooperative Institute for Research in Environmental Sciences (CIRES)University of Colorado Boulder Boulder CO USA
5. Department of ChemistryUniversity of Colorado Boulder Boulder CO USA
6. Department of Atmospheric ScienceUniversity of Wyoming Laramie WY USA
7. Now at Department of Atmospheric SciencesTexas A&M University College Station TX USA