1. State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment; Chinese Academy of Sciences; XiAn China
2. Air Quality Research Branch; Meteorological Service of Canada; Toronto, Ontario Canada
3. College of Resource and Environment; Lanzhou University; Lanzhou China
4. Institute of Cold and Arid Environment and Engineering Research; Chinese Academy of Sciences; Lanzhou China
5. Climate Data Centre, National Meteorological Canter; China Metrology Administration; Beijing China