Magnetospheric sawtooth oscillations are observed during strong and steady solar wind driving conditions. The simulation results of our global magnetohydrodynamics (MHD) model with embedded kinetic physics show that when the total magnetic flux carried by constant solar wind exceeds a threshold, sawtooth-like magnetospheric oscillations are generated. Different from previous works, this result is obtained without involving time-varying ionospheric outflow in the model. The oscillation period and amplitude agree well with observations. The simulated oscillations cover a wide range of local times, although the distribution of magnitude as a function of longitude is different from observations. Our comparative simulations using ideal or Hall MHD models do not produce global time-varying features, which suggests that kinetic reconnection physics in the magnetotail is a major contributing factor to sawtooth oscillations.

中文翻译：

---

磁层锯齿振荡的模拟：动力学重联在磁尾中的作用

在强烈和稳定的太阳风驱动条件下观察到磁层锯齿振荡。我们嵌入动力学物理的全局磁流体动力学 (MHD) 模型的模拟结果表明，当恒定太阳风携带的总磁通量超过阈值时，会产生锯齿状磁层振荡。与以往的工作不同，该结果是在模型中不涉及时变电离层流出的情况下获得的。振荡周期和振幅与观察结果吻合得很好。模拟的振荡涵盖了广泛的本地时间，尽管幅度作为经度函数的分布与观测不同。我们使用理想或霍尔 MHD 模型的比较模拟不会产生全局时变特征，