[P-EM16] Dynamics of Earth's Inner Magnetosphere and Initial Results from Arase

[PEM16-18] Magnetic field disturbances observed by Arase (ERG) associated with the magnetic dipolarization

*松岡 彩子¹、能勢 正仁²、三好 由純³、寺本 万里子³、野村 麗子⁴、藤本 晶子⁵、田中 良昌⁶、篠原 学⁷、笠原 禎也⁸、笠羽 康正⁹、石坂 圭吾¹⁰、松田 昇也³、小路 真史³、中川 朋子¹¹、篠原 育¹ (1.宇宙航空研究開発機構　宇宙科学研究所　太陽系科学研究系、2.京都大学理学部、3.名古屋大学宇宙地球環境研究所、4.宇宙航空研究開発機構　環境試験技術ユニット、5.九州大学国際宇宙天気科学・教育センター、6.国立極地研究所、7.鹿児島工業高等専門学校、8.金沢大学工学部、9.東北大学理学部、10.富山県立大学 工学部、11.東北工業大学)

キーワード：あらせ、磁場、双極子化

It is known that magnetic field disturbances often appear in the night-side magnetosphere associated with the magnetic dipolarization. The disturbances carry significant energy which is considered to be released by the global configuration change of the magnetosphere, The energy normally directs to the earth in the inner magnetosphere at the several Re distance from the earth. It suggests that the disturbances are generated in the near-earth magnetotail region, presumably about 10 Re distance from the earth. However, it is not still very clear how the magnetic field disturbances are excited and affect the particle motion in the inner magnetosphere.

The Arase (ERG) satellite was launched on December 20, 2016, to investigate the plasma physics in the inner magnetosphere. The energy exchange between particles and fields is one of the major subjects of the Arase project. We are studying the magnetic dipolarization and associated disturbances observed by Arase. The characteristics (compressibility, polarization, propagation direction, and so on) are investigated for typical events to limit the generation mechanism of the disturbances. Very close investigation of the disturbances should lead to the future statistical study, occurrence ratio, distribution and relation with the particle signature.