Responses of Magnetosphere and Ionosphere to Solar Wind Pressure impulse

Tuesday, 11 July 2017
Furong Room (Cynn Hotel)
Anmin Tian1, Xiaochen Shen1, Quanqi Shi1, Binbin Tang2, Motoharu Nowada1, Hong Wu1, ZhiHan Li1, Weiqing Yan1, Qiugang Zong3 and Suiyan Fu3, (1)Shandong University at Weihai, Weihai, China, (2)NSSC National Space Science Center, CAS, Beijing, China, (3)Peking University, School of Earth and Space Sciences, Beijing, China
Abstract:
By in-situ observations and global simulations of one case, the characteristics and generation mechanism of preliminary impulse (PI) and main impulse (MI) geomagnetic signals are studied in detail. They were induced by ionospheric twin traveling convection vortices (TCVs) caused by a sudden increase of the solar wind dynamic pressure. It is found that both dawn side PI and MI related current vortices were azimuthally seen up to 4 MLT. Based on both observation and simulation technique, we show that the MI related FACs is correlated with the large scale magnetospheric flow vortex. The flow vortex may be generated by the reflection of the fast mode waves near the ionosphere. The MHD simulation also shows that the PI related FACs may be explained by mode conversion of fast mode waves e.g. SI into the Alfvén waves. We also conducted a statistical study on both ground PI/MI events induced by the positive and negative solar wind dynamic pulses, their generation processes are compared and analyzed, and the conclusion made by the case study is further confirmed.
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