1. Department of Atmospheric Science; Colorado State University; Fort Collins Colorado USA
2. State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics; Chinese Academy of Sciences; Beijing China
3. Now at Department of Civil and Environmental Engineering; Prairie View A&M University; Prairie View Texas USA
4. Now at Department of Environmental Science; Hankuk University of Foreign Studies; Seoul South Korea
5. Department of Civil and Environmental Engineering; The Hong Kong Polytechnic University; Kowloon Hong Kong
6. Environment Research Institute; Shandong University; Jinan China