1. a Centre for Atmosphere Watch and Services, Chinese Academy of Meteorological Sciences , 46, Zhongguancun South Avenue, Haidian District, Beijing, 100081, China
2. b State Key Laboratory of Remote Sensing Science, Jointly Sponsored by the Institute of Remote Sensing Applications of the Chinese Academy of Sciences and Beijing Normal University, Institute of Remote Sensing Applications, Chinese Academy of Sciences , PO Box 9718, Beijing, 100101, China
3. c Earth System Science Center, The University of Alabama in Huntsville , 320 Sparkman Drive, Huntsville, AL, 35805, USA