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

[PEM16-21] Periodic enhancements of magnetic field, energetic particle fluxes, and high-frequency waves deep in the inner magnetosphere during substorm dipolarization: ERG observations

*宮下 幸長¹、三好 由純²、松岡 彩子³、笠原 禎也⁴、笠原 慧⁵、横田 勝一郎⁶、浅村 和史³、Wang Shiang-Yu⁷ (1.韓国天文研究院、2.名古屋大学宇宙地球環境研究所、3.宇宙航空研究開発機構 宇宙科学研究所、4.金沢大学、5.東京大学、6.大阪大学、7.Academia Sinica)

キーワード：サブストーム、内部磁気圏、磁場双極子化、ERG、あらせ

Dipolarization is one of the important processes in the magnetosphere for understanding of substorm onset and development. Using ERG (Arase) spacecraft data, we studied periodic enhancements of magnetic field, energetic particle fluxes, and high-frequency waves deep in the inner magnetosphere during substorm dipolarization. The magnetic field oscillated at a period of 1 to 2 min during dipolarization. When it enhanced, both energetic ion and electron fluxes with a few tens to hundred keV were enhanced, accompanied by broadband electromagnetic waves and high-frequency electrostatic waves from below to above the electron cyclotron frequency. The electrostatic waves were seen in the inner plasma sheet, while they were weak or were not seen away from the inner plasma sheet. We will discuss the role of the periodic enhancements of particles and waves in dipolarization and substorm development.