[P-CG21] 惑星大気圏・電磁圏

[PCG21-P15] 木星磁気圏プラズマ変動期における放射線帯電波の観測

*三澤 浩昭¹、土屋 史紀¹、佐藤 愼也¹、北 元¹、関戸 衛²、岳藤 一宏²、川合 栄治²、近藤 哲朗²、長谷川 新吾² (1.東北大学大学院理学研究科惑星プラズマ・大気研究センター、2.情報通信研究機構)

キーワード：木星、シンクロトロン電波、放射線帯、磁気圏変動

Rapid variation of relativistic electrons in Jupiter's radiation has been inferred with the time scale of a day or less from the observation of Jupiter's synchrotron radiation (JSR) at 327MHz. The Galileo Jupiter orbiter data showed this rapid variation has some relation with the (recurrent) magnetic reconfiguration events (MRE) in the outer magnetosphere, however, the causality of the rapid variation of JSR and MRE have not been known yet. One plausible causality for MRE is proposed to be enhancement of mass loading originally brought by enhancement of plasma originated from Io. In the middle of Jan. to May, 2015, obvious Io plasma enhancement has been identified by the ground-based optical observation (Yoneda et al., 2015) and also the Hisaki spacecfarft observation. This phenomena gives us a good opportunity to directly confirm the relation between the occurrence of rapid variation of Jupiter's radiation belt and enhancement of the Iogenic plasma. We have made a quasi regular JSR observation at 2.3GHz for about three weeks in March, 2015 using the Kashima 34m radio telescope with a new observation method to eliminate artificial radio noises. We will report the result of this JSR observation and discuss variation characteristics.