Propagation property of transient MHD impulses in the Magnetosphere‐Ionosphere System: The 2D model of the Pi2 pulsation
Propagation property of transient MHD impulses in the Magnetosphere‐Ionosphere System: The 2D model of the Pi2 pulsation
复制标题
磁层-电离层系统中瞬态 MHD 脉冲的传播特性：Pi2 脉动的二维模型
DOI：
10.1029/2000gl000108
复制
发表时间：
2001
影响因子：
5.2
通讯作者：
H. Nakata
中科院分区：
文献类型：
--
作者：
S. Fujita;T. Mizuta;M. Itonaga;A. Yoshikawa;H. Nakata
通过使用具有偶极子磁场、具有 Pedersen 电导率的电离层和自由外边界的磁层模型，研究了由脉冲电流引起的二维耦合 MHD 波的传播特性。这项研究是对当前楔形模型生成的 Pi2 脉动进行真实建模的第一步。数值计算表明，电离层不仅控制场线共振振荡的阻尼，还控制其频率。场线共振振荡呈现出等离子体层中沿场线的基本模式结构。在高纬度地区，电离层之间有波反弹。这表明中低纬度地区的波形与高纬度地区的波形不同。
Propagation property of the 2D‐coupled MHD wave induced from an impulsive current is studied by using a magnetospheric model having the dipole magnetic field, the ionosphere with Pedersen conductivity, and a free outer boundary. This study is the first step toward realistic modeling of Pi2 pulsation generated by the current wedge model. Numerical calculation reveals that the ionosphere controls not only damping of the field‐line resonance oscillation but also its frequency. The field‐line resonance oscillation exhibits the fundamental mode structure along the field line in the plasmasphere. In high latitudes, there are waves bouncing between the ionospheres. This suggests that the waveform in the middle‐ and low‐latitudes is different from that in high‐latitudes.