[P-EM13] Dynamics of the Inner Magnetospheric System

[PEM13-P13] Electron Dynamic Modeling during Dipolarization Substorm Events by Test Particle Simulations

*Kirolosse Mina Girgis¹, Tohru Hada^2,1, Kaiti Wang³, Fumiko Otsuka², Akimasa Yoshikawa^1,4 (1.International Research Center for Space and Planetary Environmental Science, Kyushu University, Japan, 2.Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Japan, 3.Tamkang University, Taiwan, 4.Department of Earth and Planetary Sciences, Kyushu University, Japan)

Keywords:Dipolarization, Substorm, Electron Dynamics, Test Particle Simulations

We developed a test particle simulation code to examine the electron dynamics during multiple dipolarization substorm events detected by the THEMIS mission. Through the Tao-Chan-Brizard guiding center model, we evaluated the trajectories of 0.1, 1, and 10 keV electrons with different initial pitch angles and L-shells. We applied the Tsyganenko model TS05 and the IGRF-12 to generate the time-varying magnetic field model with the corresponding inductive and polarized electric fields.
Our preliminary simulation showed that the particle flux and energy increase were enhanced in the nighttime magnetosphere during dipolarization events. Our simulation results suggest that the increase in the magnetic field in the dipolarization event and the corresponding induced/polarized electric field energizes and transports the particles earthward, which may explain the mechanism of the particle flux enhancement in the inner magnetosphere.