日本地球惑星科学連合2019年大会

講演情報

[E] ポスター発表

セッション記号 P (宇宙惑星科学) » P-EM 太陽地球系科学・宇宙電磁気学・宇宙環境

[P-EM15] 太陽地球系結合過程の研究基盤形成

2019年5月30日(木) 15:30 〜 17:00 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:山本 衛(京都大学生存圏研究所)、小川 泰信(国立極地研究所)、野澤 悟徳(名古屋大学宇宙地球環境研究所)、吉川 顕正(九州大学大学院理学研究院地球惑星科学部門)

[PEM15-P03] Motion of the inverted-V structure during an isolated substorm

*田中 杜雄1田口 聡1高須 浩平1大井川 智一1細川 敬祐2 (1.京都大学大学院理学研究科地球惑星科学専攻地球物理学教室、2.電気通信大学大学院情報理工学研究科)

キーワード:沿磁力線電流、オーロラ、inverted-V、isolated substorm

The inverted-V is an energetic electron precipitation event, which can be seen as a V-shape structure in electron flux spectrograms, and causes intense auroral arcs. Previous studies have suggested that the inverted-V structure can move fast poleward or equatorward. However, we still do not understand what drives its motion. In this study we have investigated the detailed characteristics of an inverted-V structure moving poleward, which occurred during an isolated substorm, using simultaneous observations of auroras, precipitating electrons, and field-aligned currents. We analyzed aurora data (630-nm and 557.7-nm) from an all-sky imager at Longyearbyen, Svalbard, and precipitating electrons and magnetic field data from the DMSP spacecraft (F16, F17, F18, F19). One of the interesting characteristics of the poleward-moving inverted-V is the appearance of a downward field-aligned current equatorward of and adjacent to the inverted-V. We discuss how the region of the downward field-aligned current evolves in association with the motion and growth/decay of the inverted V structure, and possibility of a role of the downward field-aligned current for the latitudinal motion of the inverted V.