Japan Geoscience Union Meeting 2015

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International Session (Poster)

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

[P-EM07] Space Weather, Space Climate, and VarSITI

Tue. May 26, 2015 6:15 PM - 7:30 PM Convention Hall (2F)

Convener:*Ryuho Kataoka(National Institute of Polar Research), Yusuke Ebihara(Research Institute for Sustainable Humanosphere, Kyoto University), Yoshizumi Miyoshi(Solar-Terrestrial Environement Laboratory, 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(Solar-Terrestrial Environment Laboratory, Nagoya University), Hiroko Miyahara(College of Art and Design, Musashino Art University), Takuji Nakamura(National Institute of Polar Research), Kazuo Shiokawa(Solar-Terrestrial Environment Laboratory, Nagoya University), Kiminori Itoh(Graduate School of Engineering, Yokohama National University)

6:15 PM - 7:30 PM

[PEM07-P01] Magnetic storms during solar 'mini-max'

*Yusuke EBIHARA1, Takashi TANAKA2, Mei-ching FOK3 (1.RISH, Kyoto University, 2.Kyushu University, 3.NASA GSFC)

Large magnetic storms, such as Dst being less than -100 nT, have rarely been observed during Solar Cycle 24. One of the reasons would be a weak driver in the solar wind. We focus on another possibility; the influence of the solar EUV radiation on the storm intensity. According to the ring current simulation coupled with the ionosphere, the intensity of the ring current becomes high when the background ionospheric conductivity is high. The reason is that the shielding electric field is weak and ions with energy of the order of keV penetrate deep into the inner magnetosphere when the ionospheric conductivity is high. According to the magnetohydrodynamics (MHD) simulation coupled with the ionosphere, the convection electric potential is weak when the background ionospheric conductivity is high. Thus, the ring current is expected to be weak because the keV ions are primarily transported from the near-earth plasma sheet by the convection electric field. This is opposite to that expected from the ring current simulation. We evaluate and discuss the overall influence of the solar radiation on the intensity of the ring current.