1. Department of Atmospheric SciencesUniversity of Illinois at Urbana‐Champaign Urbana Illinois USA
2. Now at Department of Atmospheric SciencesUniversity of Wyoming Laramie Wyoming USA
3. NASA Goddard Institute for Space Studies New York New York USA
4. Department of Geophysical SciencesUniversity of Chicago Chicago Illinois USA
5. Now at Atmospheric Modeling and Analysis Division, National Exposure Research LaboratoryU.S. Environmental Protection Agency Research Triangle Park North Carolina USA