1. College of Electrical and Power Engineering, Taiyuan University of Technology, Taiyuan 030024, China
2. Key Laboratory for Polar Science of the MNR, Polar Research Institute of China, Shanghai 200136, China
3. College of Hydro Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
4. State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China