[P-EM11] Dynamics of the Inner Magnetospheric System

[PEM11-04] Variations of the relativistic electrons of the outer belt and plasmasphere during the solar declining and minimum phase: Arase observations

*三好 由純¹、栗田 怜²、片岡 龍峰³、今城 峻²、堀 智昭¹、中村 紗都子¹、寺本 万里子⁴、三谷 烈史⁵、篠原 育⁵、浅村 和史⁵、高島 健⁵、東尾 奈々⁵、土屋 史紀⁶、熊本 篤志⁶、松田 昇也⁷、笠原 禎也⁷、松岡 彩子² (1.名古屋大学宇宙地球環境研究所、2.京都大学、3.国立極地研究所、4.九州工業大学、5.宇宙航空研究開発機構、6.東北大学、7.金沢大学)

キーワード：あらせ衛星、放射線帯、プラズマ圏

The Arase satellite has observed the inner magnetosphere from 2017 to present, which covers the declining phase and the minimum of the cycle 24 and the early rising phase of the cycle 25. Since past inner magnetosphere satellites near the equator did not cover the transition phase of two cycles, the Arase satellite has provided the unique data set of the outer belt as well as the plasmasphere. During the declining phase, the Arase satellite observed the outer belt variations associated with many coronal hole streams and several CME-driven storms. The semi-annual variations of the outer belt due to the Russel-McPherron effects are observed. The growing peak of the phase space density are observed in the heart of the outer belt and outside the plasmapause in average, which suggests that the internal acceleration process mainly works for the flux enhancements. In the early cycle 25, the Arase satellite observed the ground-minimum of the outer belt in which the flux of the MeV electrons is almost empty for a few months, and then the satellite observed significant enhancements of the outer belt associated with the storm activities of the cycle 25.