HR: 0800h
AN: SM51C-0673    [Abstracts]
TI: 2-dimensional FDTD simulations of plasma wave propagations in the ionosphere
AU: * Miyake, T
EM: miyake@pu-toyama.ac.jp
AF: Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
AU: Yoshino, S
EM: yoshino@rdw.pu-toyama.ac.jp
AF: Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
AU: Okada, T
EM: okada@pu-toyama.ac.jp
AF: Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
AU: Ishisaka, K
EM: ishisaka@pu-toyama.ac.jp
AF: Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
AB: We developed a 2-dimensional FDTD simulation code which can treat wave propagations in magnetized plasma. Though we need to perform full particle simulations in order to recognize accurate characteristics of waves propagating in space plasma, FDTD simulations can be performed with much less computer resources than those necessary for full particle simulations, in memories as well as cpu times. Since space plasma is magnetized, it is necessary to incorporate the dielectric tensor with anisotropy and dispersibility in FDTD simulation code, in order to calculate the electromagnetic field in space plasma. We use PLRC method to formulization FDTD scheme to reduce numerical errors. In FDTD simulations, it is essential that how to realize an effective absorbing boundary. We developed PML absorbing boundary condition with anisotropy and dispersibility, and succeeded to realize very effective absorbind boundary. According to the rocket observations, we can receive MF radio wave above the dense ionospheric layer whose density is larger than those corresponding to cutoff frequency of MF radio wave. We consider that this is because the thickness of the ionopheric layer is smaller than the wavelength of MF radio wave, the density of ionospheric layer is not constant in the horizontal plane. We have been analyzing the characteristics of MF wave propagation in the ionospher with Full-wave method. In the Full-wave method, since the electron density profile is assumed to change in one-dimensional corrsponding to the alititude, we can only treat one-dimensional electron density profiles. In this study, therefore, we performed a series of FDTD simulations of MF wave propagations in ionospheres with several types of electron density distributions in the horizontal plane, such as electron dense cloud, sporadic layer, etc., and studied the relation between spatial scale of ionospheric layer and MF radio wavelength. In addition, we performed a FDTD simulation of MF radio wave propagations with the ionospheric layer model which is estimated by Full-wave analysis of S-310-37 sounding rocket observations. S-310-37 sonding rocket was launched at USC (Uchinoura Space Center, Kagoshima) in Jan. 2007. We are going to compare FDTD simulation results, Full-wave analysis and rocket observations, and study the influence of electron density profile on the propagation characterictics of MF radio wave in the ionosphere.
DE: 2700 MAGNETOSPHERIC PHYSICS (6939)
DE: 6929 Ionospheric physics (1240, 2400)
DE: 6964 Radio wave propagation
DE: 6984 Waves in plasma (7867)
DE: 6994 Instruments and techniques (1241)
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting