日本地球惑星科学連合2018年大会

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[EE] Evening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-EM12] Space Weather, Space Climate, and VarSITI

2018年5月24日(木) 17:15 〜 18:30 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:片岡 龍峰(国立極地研究所)、Antti A Pulkkinen (NASA Goddard Space Flight Center)、草野 完也(名古屋大学宇宙地球環境研究所、共同)、塩川 和夫(名古屋大学宇宙地球環境研究所)

[PEM12-P01] Magnetohydrodynamic Simulation of the Solar Active Region 12673 and eruption accompanied with a Great Solar Flare

*井上 諭1伴場 由美2塩田 大幸3,1Sung-Hong Park1 (1.名古屋大学宇宙地球環境研究所、2.宇宙航空研究開発機構 宇宙科学研究所、3.情報通信研究機構)

キーワード:太陽フレア、コロナ質量放出、電磁流体力学

The solar active region (AR) 12673 came out on September 2017 and exhibited rapid evolution during few days. Consequently, the AR12673 produced 4 X-class flares and 27 M-class flares from 2017 September 4 to 10, including a great solar flare (X9.3 flare) which is ranked as largest in the solar cycle 24. In order to reveal a dynamics of the great solar flare, we performed a Magnetoydrodynamic (MHD) simulation. We first reconstructed a three-dimensional magnetic field based on the phtospheric magnetic field, which is obtained prior to the flare, through the MHD relaxation method and then put it in the MHD simulation as the initial condition.

The MHD simulation exhibited a drastic eruption, in particular, we found that a highly twisted flux tube is formed during the eruption through a reconnection of multiple twisted lines formed prior to the flare, and it eventually exhibited a writhe motion. The writhe motion is due to the kink instability because the eruptive flux tube is ultimately composed of highly twisted lines with more than required threshold of the kink instability. Because the reconstructed magnetic field prior to the flare has no such highly twisted lines leading the instability, this writhe motion would come from the nonlinear evolution of the eruptive flux tube. Furthermore, this writhe motion might explain the southward magnetic fields observed in vicinity of Earth whereas the northward magnetic fields were expected from solar observations. We will discuss more detailed dynamics and compare with solar observations and results obtained from solar wind simulation (SUSANOO).