[P-EM26] Space Plasma Physics: Theory and Simulation

[PEM26-P09] 3-dimentional electromagnetic particle simulations about the low frequency component of Broadband Electrostatic Noise

*Taketoshi MIYAKE¹, Sho NAGAYASU¹, Masaki OKADA², Yoshiharu OMURA³, Hirotsugu KOJIMA³ (1.Toyama Prefectural University, 2.National Institute of Polar Research, 3.RISH, Kyoto University)

Keywords:particle simulations, low frequecy component of BEN, Geotail, EFD

According to PIC simulations, ESW (Electrostatic Solitary Waves) are
generated from electron beam instabilities. ESW correspond the upper
frequency component of BEN (Broadband Electrostatic Noise) which is
frequently observed in space plasma. The generation mechanism of the
low frequency component of BEN, however, is still unexplained.
To clarify whether such low frequency waves are generated, we made
statistical analysis on generation conditions of low frequency component
of BEN observed by Electric Field Detector (EFD) onboard Geotail
spacecraft. We detected low frequency component of BEN automatically
from EFD data, and made an occurrence frequency distribution of these
waves. Low frequency component of BEN are observed in PS and PSBL region
in the magnetosphere.
We studied several plasma parameters at the time when low frequency
component of BEN were observed, and found that these waves were observed
in the conditions with low ion density and strong B field in these
regions. Then, based on these statistical analysis, we are going to
perform a series of three-dimensional electromagnetic particle
simulations with different parameters on PC-Cluster built in our
laboratory.