Study of Plasma Wave Propagation Based on Magnetotail MHD Modelling

基于磁尾MHD建模的等离子体波传播研究

• 批准号: 05640487
• 负责人: OMURA Yoshiharu
• 金额: $ 1.34万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05640487/
• 关键词: Simulation; Ray Tracing; Plasma Wave; Reconnection; MHD; Magnetosphere; Wave Propagation; GEOTAIL

We have clarified propagation characteristic of various kinds of plasma waves in the magnetotail based on the MHD simulation model which gives a self-consistent model of the magnetic field and plasma density. We first used a 2D MHD model of a plasmoid in the magnetotail region. After clarifying the propagation characteristics of various kinds of plasma waves in the 2D model, we extended the study to a 3D model. In applying the MHD models to the ray tracing, we introduced a new method to interpolate the plasma density and the magnetic field from those defined at the discrete spatial grid points, while the density and magnetic field models are given as an analytic functions in the previous ray tracing studies. We assumed a source of the plasma waves in the X-point reconnection region associated with the plasmoid. We traced the propagation paths of the various kinds of electromagnetic waves for all possible propagation angles. We obtained a "ray density" from the spatial distribution of the rays. We obtained the ray densities for various electromagnetic waves in the range from a very low frequency less than the ion cyclotron frequency up to the high frequency higher than the electron plasma frequency. Through visualization of the ray densities in the 3D model via the AVS graphic system, we have identified the propagation characteristics of ion cyclotron waves, lower hybrid waves, whistler mode waves, L-O mode waves in the magnetotail. Based on the database of the ray density, we simulated dynamic spectra of electromagnetic waves as observed by a spacecraft which traverses the plasmoid in the magnetotail.

基于MHD仿真模型，我们阐明了磁尾中各种等离子体波的传播特性，给出了磁场和等离子体密度的自洽模型。我们首先使用磁尾区域等离子体团的 2D MHD 模型。在明确了2D模型中各种等离子体波的传播特性后，我们将研究扩展到3D模型。在将 MHD 模型应用于射线追踪时，我们引入了一种新方法，根据离散空间网格点定义的等离子体密度和磁场来插值，而密度和磁场模型在之前的射线追踪研究中作为解析函数给出。我们假设等离子体波源位于与等离子体团相关的 X 点重联区域。我们追踪了各种电磁波在所有可能的传播角度下的传播路径。我们从射线的空间分布中获得了“射线密度”。我们获得了从低于离子回旋加速器频率的极低频率到高于电子等离子体频率的高频范围内的各种电磁波的射线密度。通过AVS图形系统对3D模型中的射线密度进行可视化，我们识别了磁尾中离子回旋波、低混合波、哨声模式波、L-O模式波的传播特性。基于射线密度数据库，我们模拟了航天器穿过磁尾等离子体团所观察到的电磁波动态谱。

项目成果

A.L.Brinca,Y.Omura and H.Matsumoto: "Linear Coupling Effects Originated in Electron Nongyrotropy" Journal of Geophysical Research. 98. 21071-21076 (1993)

A.L.Brinca、Y.Omura 和 H.Matsumoto：“电子非自转性中起源的线性耦合效应”地球物理研究杂志。

Y.Omura: "Computer simulation of electrostatic solitary waves: A non-linear model of broadband electrostatic noise" Geophysical Research Letters. 21. 2923-2926 (1994)

Y.Omura：“静电孤立波的计算机模拟：宽带静电噪声的非线性模型”地球物理研究快报。

Reiff,P.H.: "Remote sensing of substorm dynamics via radio sounding" Substorms 2: Proceedings of the Second International Conference on Substorms, edited by J.R.Kan. (1994)

Reiff,P.H.：“通过无线电探测对亚暴动态进行遥感”《亚暴 2：第二届国际亚暴会议论文集》，J.R.Kan 编辑。

Reiff, P.H., J.L.Green, R.F.Benson, D.L.Carpenter, W.Calvert, S.F.Fung, D.L.Gallagher, Y.Omura, B.W.Reinisch, M.F.Smith, and W.W.L.Taylor: "Remote sensing of substorm dynamics via radio sounding" Substorms 2 : Proceedings of the Second International Confe

Reiff, P.H.、J.L.Green、R.F.Benson、D.L.Carpenter、W.Calvert、S.F.Fung、D.L.Gallagher、Y.Omura、B.W.Reinisch、M.F.Smith 和 W.W.L.Taylor：“通过无线电探测对亚暴动态进行遥感” 亚暴 2：

Y.Omura,H.Kojima,H,Matsumoto: "Computet Simulation of Electrostatic Solitary Waves:A Nonlinear Model of Broadband Electrosratic Noise" Geophysical Research Letters. 21. 2923-2926 (1994)

Y.Omura、H.Kojima、H、Matsumoto：“静电孤立波的计算机模拟：宽带电激噪声的非线性模型”地球物理研究快报。