Japan Geoscience Union Meeting 2018

Presentation information

[EE] Oral

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

[P-EM16] Dynamics of Earth's Inner Magnetosphere and Initial Results from Arase

Mon. May 21, 2018 3:30 PM - 5:00 PM 303 (3F International Conference Hall, Makuhari Messe)

convener:Danny Summers(Memorial University of Newfoundland), Yoshizumi Miyoshi(Institute for Space-Earth Environmental Research, Nagoya University), Keisuke Hosokawa(電気通信大学大学院情報理工学研究科, 共同), Yusuke Ebihara(Research Institute for Sustainable Humanosphere, Kyoto University), Chairperson:Ebihara Yusuke(RISH, Kyoto University)

4:30 PM - 4:45 PM

[PEM16-17] Rapid acceleration of outer radiation belt electrons associated with solar wind pressure pulse: Arase and Van Allen Probe observations and code-coupling simulation

Masahiro Hayashi1, *Yoshizumi Miyoshi1, Shinji Saito1, Yosuke Matsumoto2, Satoshi Kurita1, Ito Hiroki1, Mariko Teramoto1, Tomoaki Hori1, Shoya Matsuda1, Masafumi Shoji1, Shinobu Machida1, Takanobu Amano3, Kanako Seki3, Nana Higashio4, Takefumi Mitani4, Takeshi Takashima4, Yoshiya Kasahara5, Yasumasa Kasaba6, Keigo Ishisaka7, Fuminori Tsuchiya6, Atsushi Kumamoto6, Ayako Matsuoka4, Iku Shinohara4 (1.Institute for Space-Earth Environmental Research,Nagoya University, 2.Chiba University, 3.The University of Tokyo, 4.Japan Aerospace Exploration Agency, 5.Kanazawa University, 6.Tohoku University, 7.Toyama Prefectural University)

Keywords:Arase, Radiation belt, electron acceleration

Relativistic electron fluxes of the outer radiation belt rapidly change in response to solar wind variations. One of the shortest acceleration processes of electrons in the outer radiation belt is caused by interactions between drifting electrons and fast-mode waves induced by compression of the dayside magnetopause associated with interplanetary shocks. In order to investigate this process, we investigate the Sutorm Suddun Commencement (SSC) event on July 16, 2017 using the Arase(ERG) satellite and Van Allen Probes. The satellites observed the rapid flux enhancement of sub-relativistic and relativistic electrons for wide energy range associated with the fast mode waves. In order to investigate these wide energy electron acceleration associated with the fast mode waves, we perform a code-coupling simulation using the GEMSIS-RB test particle simulation (Saito et al., 2010) and the GEMSIS-GM global MHD magnetosphere simulation (Matsumoto et al., 2010). As a case study, an interplanetary pressure pulse with the enhancement of ~2 nPa is used to investigate the compression of the dayside magnetopause and subsequent propagation of the fast mode waves. The fast mode waves with the azimuthal electric field ( negative Ephi : |Ephi| ~ 10 mV/m, azimuthal mode number : m ≦ 2 ) propagates from the dayside to nightside, interacting with electrons. The simulation results indicate the flux enhancments in the wide energy range after the fast mode wave propagation. Condiering the interaction process, we derive the critical energy for the acceleration. The high energy electrons above the critical energy can be effectively accelerated by the fast mode waves, and these tendency seem to be consistent with the observations.