1. Shandong Provincial Key Laboratory of Optical Astronomy and Solar‐Terrestrial Environment, School of Space Science and PhysicsShandong University Weihai China
2. School of Earth and Space SciencesPeking University Beijing China
3. Key Laboratory of Earth and Planetary PhysicsInstitute of Geology and Geophysics, Chinese Academy of Sciences Beijing China
4. Physics and Astronomy DepartmentDartmouth College Hanover New Hampshire USA