1. Laboratory for Climate Studies, National Climate Center, China Meteorological Administration, Beijing 100081, PR China
2. Department of Atmospheric Science, School of Environmental Studies, China University of Geosciences, Wuhan 430074, PR China
3. College of Geographical Sciences and Tourism, Jilin Normal University, Siping 136000, PR China
4. National Meteorological Information Center, China Meteorological Administration, Beijing 100081, PR China