日本地球惑星科学連合2018年大会

講演情報

[EE] ポスター発表

セッション記号 P (宇宙惑星科学) » P-PS 惑星科学

[P-PS01] Outer Solar System Exploration Today, and Tomorrow

2018年5月21日(月) 15:30 〜 17:00 ポスター会場 (幕張メッセ国際展示場 7ホール)

コンビーナ:木村 淳(大阪大学)、笠羽 康正(東北大学大学院 理学研究科 地球物理学専攻)、Vance Steven(Jet Propulsion Laboratory, Caltech、共同)、Kunio M. Sayanagi (Hampton University)

[PPS01-P10] Identification of Jupiter's hectometric radiation associated with reconnection in the magnetotail

*三澤 浩昭1土屋 史紀1水口 岳宏1 (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)

キーワード:木星、ヘクトメーター電波、磁気再結合

It is known that Jupiter's radio emission in the hectometric wave range (HOM) shows two type occurrence components. One is a component relating to solar wind variations (sw-HOM) appearing around CML(Central Melian system III Longitude of an observer)=180deg when solar wind pressure enhances. Another one is generally more intense than sw-HOM and has no or weak relation with solar wind variations (nsw-HOM) appearing around CML=110deg and 280deg as the two major components when De (Jovicentric declination of an observer)=-1deg (Nakagawa, 2003). The nsw-HOM is thought to be generated by some internal processes initiated by the rapid planetary rotation and massive plasma, however precise source processes and locations have not been clarified yet.
We have reanalyzed occurrence characteristics of HOM using the WIND data to investigate precise relation between occurrence of nsw-HOM and Jupiter's magnetospheric variations observed by the Galileo Jupiter orbiter. As a result, we found that HOM has the 3rd nsw-HOM component appearing from 340deg to +20deg in CML which generally appears quasi periodically with the time scale of a few to several days and also shows long-term occurrence variations with seemingly capricious time scales. A comparison study between the occurrence timing of the 3rd nsw-HOM and magnetospheric events for the Galileo era indicates that most of the 3rd nsw-HOM appeared when magnetic reconfiguration events occurred in the magnetotail region. We show the precise occurrence features of the 3rd nsw-HOM and discuss their possible source locations based on a comparison study with Jupiter's UV auroral images.