JpGU-AGU Joint Meeting 2017

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-EM 太陽地球系科学・宇宙電磁気学・宇宙環境

[P-EM14] [EE] Dynamics in magnetosphere and ionosphere

2017年5月20日(土) 10:45 〜 12:15 ポスター会場 (国際展示場 7ホール)

コンビーナ:堀 智昭(東京大学大学院理学系研究科)、田中 良昌(国立極地研究所)、中溝 葵(情報通信研究機構 電磁波計測研究所)、尾崎 光紀(金沢大学理工研究域電子情報学系)

[PEM14-P23] Simultaneous existence of the cusp aurora and polar cap arcs during northward IMF

*織田 優心1田口 聡1細川 敬祐2 (1.京都大学大学院理学研究科、2.電気通信大学大学院情報理工学研究科)

キーワード:cusp aurora, northward IMF, polar cap arcs

The cusp aurora for northward IMF is created by the particle precipitation caused by high-latitude reconnection poleward of the cusp. The aurora generally appears at 75 - 80 MLAT in the daytime sector. In this sector the polar cap arcs are also often seen when IMF is northward. In this research we show the spatial and temporal features of the cusp aurora and polar cap arcs by examining events in which both exist simultaneously. We analyzed the 630 nm auroral image data from a highly sensitive all-sky imager at Longyearbyen, Svalbard in Norway, and the precipitating particle and ion drift data from the DMSP spacecraft. The spacecraft data show that lobe convection exists in the daytime sector, and that the cusp electron precipitation and higher-energy electron precipitation occur at different places simultaneously. It is also clear from the all-sky image data that the former and latter produce the cusp aurora and polar cap arcs, respectively. Detailed examination of the all-sky image data obtained immediately before and after the time when whether the observed auroral structures are the cusp proper or polar cap arcs are undoubtedly determined reveals their spatial and temporal features.