Japan Geoscience Union Meeting 2016

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International Session (Poster)

Symbol P (Space and Planetary Sciences) » P-EM Solar-Terrestrial Sciences, Space Electromagnetism & Space Environment

[P-EM04] Space Weather, Space Climate, and VarSITI

Sun. May 22, 2016 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall HALL6)

Convener:*Ryuho Kataoka(National Institute of Polar Research), Antti Pulkkinen(NASA GSFC), Yusuke Ebihara(Research Institute for Sustainable Humanosphere, Kyoto University), Yoshizumi Miyoshi(Institute for Space-Earth Environmental Research, Nagoya University), Toshifumi Shimizu(Institute of Space and Astronautical Science, JAXA), Ayumi Asai(Unit for Synergetic Studies of Space, Kyoto University), Hidekatsu Jin(National Institude of Information and Communications Technology), Tatsuhiko Sato(Japan Atomic Energy Agency), Kanya Kusano(Institute for Space-Earth Environmental Research, Nagoya University), Hiroko Miyahara(College of Art and Design, Musashino Art University), Kiminori Itoh(Graduate School of Engineering, Yokohama National University), Kazuo Shiokawa(Institute for Space-Earth Environmental Research, Nagoya University), Takuji Nakamura(National Institute of Polar Research), Shigeo Yoden(Division of Earth and Planetary Sciences, Graduate School of Science, Kyoto University), Kiyoshi Ichimoto(Kwasan and Hida Observatories, Kyoto University), Mamoru Ishii(National Institute of Information and Communications Technology)

5:15 PM - 6:30 PM

[PEM04-P04] Double Arc Instability in the solar corona

*Naoyuki Ishiguro1, Kanya Kusano1,2 (1.Institute for Space-Earth Environmental Research, Nagoya University, 2.Japan Agency for Marine-Earth Science and Technology)

Keywords:Sun, solar flare, instability

The stability of flux rope in the solar corona must be related to the occurrence of solar flares and coronal mass ejections (CMEs), which are primary cause of solar weather disturbance. Torus Instability (TI) was recently proposed by Kliem & Toeroek (2006) as the cause of solar eruptions. However, how the instability can be initiated is not yet well understood. On the other hand, one of the most likely scenario for the process causing unstable flux rope is the tether-cutting reconnection suggested by Moore et al. (2001). This scenario suggests that magnetic reconnection between sheared magnetic fields forms a double-arc loop which can erupts. However, the stability of double-arc loop was not analyzed yet.
The objective of this study is to analyze the stability of double-arc loop theoretically. We model double-arc electric current loop using two circular tori connected each other, and numerically calculate the stability of it. As the result, we found that the double-arc current loop can be destabilized even if the external field is uniform in contrast to the TI. The results indicate that the Double-Arc Instability (DAI) is different from the TI. The decay index which is used as a criteria for TI is not applicable to DAI. Furthermore, we found that in order to make the DAI the twist of magnetic field line must be larger than one-half. We also show that the growth of DAI is similar to the observation of flux eruption. These results indicate that the DAI caused by the tether cutting reconnection is a possible scenario, which can well explain how solar eruption can be triggered.