论文标题
在电子注入过程中，由动力学alfvén波驱动的数十个至数百个keV电子降水
Tens to hundreds of keV electron precipitation driven by kinetic Alfvén waves during an electron injection
论文作者
论文摘要
电子注射是与磁层实量相关的关键过程，它们将明显的电子能量沉积到电离层中。尽管对注射过程中的$ <$ 10 keV电子的波散射进行了充分的研究，但磁尾电子注射与能量（$ \ geq $ 100 keV）电子沉淀之间的连接仍然难以捉摸。使用ELFIN和磁层多尺度（MMS）任务之间的共轭观测，我们向数百个keV电子沉淀提供了数十个keV电子沉淀的证据，这可能是由动力学Alfvén波（KAWS）驱动的电离层的，该波动层可能与磁轨电子注射和磁场梯度相关。适应观察结果的测试粒子模拟表明，偶极化 - 前磁场梯度和相关的$ \ nabla b $漂移允许注射的电子和KAWS之间的多普勒移位的Landau共振，从而在横跨前面产生电子空间散射，从而导致音高垂垂降低和后续沉淀。测试粒子结果表明，这种KAW驱动的降水可以解释低于$ \ sim $ 300 kev的精灵观测值。
Electron injections are critical processes associated with magnetospheric substorms, which deposit significant electron energy into the ionosphere. Although wave scattering of $<$10 keV electrons during injections has been well studied, the link between magnetotail electron injections and energetic ($\geq$100 keV) electron precipitation remains elusive. Using conjugate observations between the ELFIN and Magnetospheric Multiscale (MMS) missions, we present evidence of tens to hundreds of keV electron precipitation to the ionosphere potentially driven by kinetic Alfvén waves (KAWs) associated with magnetotail electron injections and magnetic field gradients. Test particle simulations adapted to observations show that dipolarization-front magnetic field gradients and associated $\nabla B$ drifts allow Doppler-shifted Landau resonances between the injected electrons and KAWs, producing electron spatial scattering across the front which results in pitch-angle decreases and subsequent precipitation. Test particle results show that such KAW-driven precipitation can account for ELFIN observations below $\sim$300 keV.
