1. Key Laboratory of Earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China
2. College of Earth and Planetary Sciences University of Chinese Academy of Sciences Beijing China
3. Now at Center for Space Physics and Department of Astronomy Boston University Boston MA USA
4. Max‐Planck‐Institute for Solar System Research Göttingen Germany
5. Swedish Institute of Space Physics Kiruna Sweden
6. Finnish Meteorological Institute Helsinki Finland
7. Swedish Institute of Space Physics Uppsala Sweden
8. Center for Space Physics and Department of Astronomy Boston University Boston MA USA