1. Department of Earth Sciences; VU University; De Boelelaan 1085 1081 HV Amsterdam The Netherlands
2. Departments of Earth Sciences and Geography; University of Ottawa; Ottawa Ontario Canada K1N 6N5
3. Department of Geography; University of Victoria; Victoria British Columbia Canada V8W 3R4
4. P.O. Box 138 050000 Almaty Kazakhstan
5. Geophysical Institute; UAF; 903 Koyukuk Dr., P.O. Box 757320 Fairbanks AK 99775-7320 USA
6. Geographical Institute RAS; Staromonetny 29, 110017 Moscow Russia
7. State Key Laboratory of Frozen Soils Engineering; Cold and Arid Regions Environmental and Engineering Research Institute CAS; 326 West Donggang Road Lanzhou 730000 China
8. College of Urban and Environmental Sciences; Peking University; Beijing 100871 China
9. College of Earth and Environmental Sciences; Lanzhou University; Lanzhou 730000 China
10. National Snow and Ice Data Centre (NSIDC); University of Colorado at Boulder; Boulder CO 80309-0449 USA
11. Research School of Arid Environment and Climate Change; Lanzhou University; Lanzhou 730000 China