1. Atmospheric Chemistry Division, NCAR Earth System Laboratory; National Center for Atmospheric Research; Boulder Colorado USA
2. Now at Department of Earth System Science, School of Physical Sciences; University of California; Irvine California USA
3. Department of Chemistry; University of Toronto; Toronto Ontario Canada
4. Now at Department of Chemistry; Memorial University of Newfoundland, St. John's; Newfoundland Canada
5. NOAA Earth System Research Laboratory; Chemical Sciences Division; Boulder Colorado USA
6. Cooperative Institute for Research in Environmental Sciences; University of Colorado Boulder; Boulder Colorado USA
7. Department of Atmospheric Sciences; University of Washington; Seattle Washington USA
8. Natural Resources and Earth System Science Program; University of New Hampshire; Durham New Hampshire USA
9. Department of Chemistry; Appalachian State University; Boone North Carolina USA