We investigated the excitation mechanism and global distribution of internally driven Pc3‐Pc5 ultralow‐frequency waves in the inner magnetosphere using a kinetic and self‐consistent simulation (Geospace Environment Modeling System for Integrated Studies‐Ring Current model). These waves can be excited through the drift‐bounce resonance with ring current ions injected into the inner magnetosphere during substorms. Initial phase space density of ring current ions is the butterfly‐like distribution with the asymmetry in pitch angle direction. We find two kinds of internally driven ultralow‐frequency waves. First, the dynamic power spectra of the field fluctuations show the excitation of poloidal, toroidal, and compressional Pc5 waves. We find that the excited waves are fundamental modes propagating westward with the azimuthal wave number of m ~ − 50. These waves are excited by the drift resonance with ions having the energy of 50–150 keV. Second, we can reproduce the excitation of poloidal Pc3 waves in the dusk region with m ~ − 30, which are driven by the bounce resonance with ions having energies of 20–50 keV for the first time. We investigate the energy transfer between ions and waves and find that poloidal Pc5 and Pc3 waves are excited mainly by positive energy gradient of the phase space density, while we find the inward gradient of the phase space density at L > 6. The velocity distribution of the growth rate suggests that Pc5 waves are driven by ions with pitch angle of around 90°, while Pc3 waves are excited by ions at oblique pitch angle.

中文翻译：

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基于漂移运动学模拟的带有振铃电流离子的漂移弹跳共振对内部驱动的ULF波的激励

我们使用动力学和自洽模拟（用于集成研究的环空环境建模系统-环流模型）研究了内部磁层中内部驱动的Pc3-Pc5超低频波的激发机理和全局分布。在副风暴期间，通过将环状电流离子注入内部磁层，可以通过漂移反弹共振来激发这些波。环流离子的初始相空间密度是蝶形分布，在螺距角方向上具有不对称性。我们发现两种内部驱动的超低频波。首先，场涨落的动态功率谱显示了极性，环形和压缩性Pc5波的激发。我们发现，激发波是向西传播的基本模式，其方位角波数为m〜−  50。这些波被能量为50–150 keV的离子的漂移共振激发。其次，我们可以重现极向PC3波的激励在黄昏区域与米 〜 - 30，其由弹跳共振与具有20-50千电子伏的能量的离子的第一次驱动。我们研究了离子与波之间的能量转移，发现极点Pc5和Pc3波主要由相空间密度的正能量梯度激发，而我们发现L  > 6时相空间密度的向内梯度。增长率表明，Pc5波是由倾斜角约为90 °的离子驱动的，而Pc3波是由斜倾斜角的离子激发的。