1. Department of Chemistry and Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado 80309, United States
2. Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark
3. Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), UMR CNRS 7583, Institut Pierre Simon Laplace (IPSL), Université Paris-Est Créteil (UPEC) et Université de Paris (UP), 94010 Creteil, France