Acceleration of outer radiation belt electrons associated with solar wind pressure pulse: MHD-test particle simulation study and Arase and Van Allen Probe observations

Miyoshi, Yoshizumi

Acceleration of outer radiation belt electrons associated with solar wind pressure pulse: MHD-test particle simulation study and Arase and Van Allen Probe observations

Monday, 5 March 2018: 15:45

Longshot and Bogey (Hotel Quinta da Marinha)

Yoshizumi Miyoshi¹, Masahiro Hayashi¹, Shinji Saito¹, Yosuke Matsumoto², Satoshi Kurita¹, Mariko Teramoto¹, Tomoaki Hori¹, Masafumi Shoji³, Shinobu Machida⁴, Takanobu Amano⁵, Kanako Seki⁶, Nana Higashio⁷, Takefumi Mitani⁸, Takeshi Takashima⁹, Yoshiya Kasahara¹⁰, Yasumasa Kasaba¹¹, Keigo Ishisaka¹², Fuminori Tsuchiya¹¹, Ayako Matsuoka³, Iku Shinohara³, J Bernard Blake¹³, Joseph F. Fennell¹³ and Seth G Claudepierre¹³, (1)Nagoya University, Nagoya, Japan, (2)Chiba University, Chiba, Japan, (3)ISAS/JAXA, Sagamihara, Japan, (4)Nagoya University, Institute for Space-Earth Environmental Research, Nagoya, Japan, (5)University of Tokyo, Bunkyo-ku, Japan, (6)The University of Tokyo, Tokyo, Japan, (7)JAXA, Tukuba, Japan, (8)ISAS/JAXA, Kanagawa, Japan, (9)ISAS Institute of Space and Astronautical Science, Kanagawa, Japan, (10)Kanazawa University, Kanazawa, Japan, (11)Tohoku University, Sendai, Japan, (12)Toyama Prefectural University, Imizu, Japan, (13)Aerospace Corporation, Los Angeles, CA, United States

Abstract:

Relativistic electron fluxes of the outer radiation belt rapidly change in response to solar wind variations. Fast mode waves induced by compression of the dayside magnetopause causes the shortest acceleration of energetic electrons in the outer radiation belt In order to investigate this process, especially, conditions for acceleration as well as evolution of energy spectrum of electrons, we conduct 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 ~5 nPa is used as the up-stream condition to drive the MHD simulation. As a result, the fast mode waves with the small mode number propagates from the dayside to nightside, interacting with electrons and rapid accelerations for wide energy range are observed. Considering the simulation results, we investigate a model for rapid acceleration of electrons and derive the critical energy for efficient accelerations. We will compare our simulation results with observations from Arase and Van Allen Probes on energy spectrum and pitch angle distribution, and we will investigate the acceleration condition of relativistic electrons associated with storm sudden commencement (SSC).