1. SIGMA Weather Group, State Key Laboratory of Space Weather, CSSAR; Chinese Academy of Sciences; Beijing China
2. Department of Earth and Planetary Sciences, Faculty of Sciences; Kyushu University; Fukuoka Japan
3. School of Electrical Engineering; Aalto University; Espoo Finland
4. Finnish Meteorological Institute; Helsinki Finland
5. Department of Physics and Technology; University of Bergen; Bergen Norway
6. Key Laboratory of Ionospheric Environment, Institute of Geology and Geophysics; Chinese Academy of Sciences; Beijing China
7. Beijing National Observatory of Space Environment, Institute of Geology and Geophysics; Chinese Academy of Sciences; Beijing China