Japan Geoscience Union Meeting 2015

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International Session (Oral)

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

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

Mon. May 25, 2015 4:15 PM - 6:00 PM 302 (3F)

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), Chair:Yusuke Ebihara(Research Institute for Sustainable Humanosphere, Kyoto University)

4:15 PM - 4:45 PM

★ [PEM07-26] Wide energy electron precipitation associated with the pulsating aurora and its impact on the middle atmosphere

*Yoshizumi MIYOSHI1, Shin-ichiro OYAMA1, Shinji SAITO1, Satoshi KURITA1, Hitoshi FUJIWARA2, Ryuho KATAOKA3, Yusuke EBIHARA4, Craig Kletzing5, Geoff Reeves6, Ondrej Santolik7, Mark Clilverd8, Craig Rodger9, Esa Turunen10, Fuminori TSUCHIYA11 (1.Solar-Terrestrial Environment Laboratory, Nagoya University, 2.Seikei University, 3.National Institute of Polar Research, 4.RISH, Kyoto University, 5.University of Iowa, USA, 6.Los Alamos National Laboratory, USA, 7.Charles University in Prague, Czech Rep., 8.British Antarctic Survey, UK, 9.University of Otago, NZ, 10.Sodankyla Geophysical Observatory, University of Oulu, Finland, 11.PPARC, Tohoku University)

Keywords:energetic electron precipiation, Geospace, middle atmosphere

The pulsating aurora are caused by intermittent precipitations of tens keV electrons. It is also expected that not only tens keV electrons but also sub-relativistic/relativistic electrons precipitate simultaneously into the ionosphere owing to whistler-mode wave-particle interactions. We analyzed the pulsating aurora event in November 2012 using several ground-based observation data; EISCAT, riometer, and sub-ionospheric radio waves, and the Van Allen Probes satellite data. The electron density profile obtained from EISCA Tromso VHF radar identify the electron density enhancement at >68 km altitudes. The electron energy spectrum derived from the inversion method indicates the wide energy electron precipitations from 10 keV ? 200 keV. The riometer and network of subionospheric radio wave observations also showed the energetic electron precipitations during this period. During this period, the footprint of the Van Allen Probe-A satellite was very close to Tromso and the satellite observed rising tone emissions of the lower-band chorus (LBC) waves near the equatorial plane. Using the satellite observed LBC and trapped electrons as an initial condition, we conducted a computer simulation of the wave-particle interactions. The simulation showed simultaneous precipitation of electrons at both tens of keV and a few hundred keV, which is consistent with the energy spectrum estimated by the inversion method using the EISCAT observations. This result revealed that electrons with a wide energy range simultaneously precipitate into the ionosphere in association with the pulsating aurora. We also discuss the possible impacts on the middle atmosphere due to precipitations of wide energy electrons during the pulsating aurora.