1. School of Earth and Space SciencesPeking University Beijing China
2. Department of Earth, Planetary, and Space SciencesUniversity of California Los Angeles CA USA
3. School of Space Science and PhysicsShandong University Weihai China
4. Laboratoire de Physique Atmosphérique et Planétaire, STAR InstituteUniversité de Liège Liège Belgium
5. Center for Space PhysicsBoston University Boston MA USA