1. Earth System Science Programme, Faculty of Science; The Chinese University of Hong Kong; Hong Kong
2. National Snow and Ice Data Center; University of Colorado Boulder; Boulder Colorado USA
3. Department of Geophysics; Stanford University; Stanford California USA
4. International Arctic Research Center; University of Alaska Fairbanks; Fairbanks Alaska USA
5. Key Laboratory of Western China's Environmental Systems, College of Earth and Environmental Sciences; Lanzhou University; Lanzhou China