1. Department of Atmospheric and Oceanic Science, University of Maryland, College Park, MD 20742, USA
2. National Climate Center, Chinese Meteorological Administration, Beijing, China.
3. Research Center for Sustainable Development, Chinese Academy of Social Sciences, Beijing, China.
4. Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China.
5. Department of Geography, University of Maryland, College Park, MD 20742, USA