R Guo (Key Laboratory of Earth and Planetary Physics), Z Pu (School of Earth and Space Sciences), Z Yao (Laboratoire de Physique Atmospherique et Planetaire), M Dunlop (STFC Rutherford Appleton Lab., and Beihang Univ., China), YV Bogdanova (STFC Rutherford Appleton Lab.), Y Wei (Key Laboratory of Earth and Planetary Physics), X Wang (Harbin Institute of Technology), C Xiao (School of Physics), J He (School of Earth and Space Sciences), S Fu (School of Earth and Space Sciences), L Xie (School of Earth and Space Sciences), AN Fazakerley (UCL Mullard Space Science Laboratory), W Wan (Key Laboratory of Earth and Planetary Physics)