GEM: Generation of Very Low Frequency (VLF) Whistler Waves and Resulting Wave-Particle Interactions in the Radiation Belt

这个项目将使用二维电磁达尔文粒子-细胞模拟来自我一致地确定在各种条件下如何在磁层中产生哨声波，并了解随后的波粒相互作用。非线性波-粒子和波-波相互作用是这一问题的重要方面，因此有必要在细胞模拟中使用粒子。最近的观测和理论工作表明，哨声模波可以相对于环境磁场倾斜传播，因此需要一种多维方法。模拟将在下一代计算平台上运行，该平台将允许包含辐射带区域的真实参数，并将与观测到的波和粒子数据密切协调使用，以研究哨声波和合唱波的增长、幅度和波传播特性，其结构谱的形成，以及哨声对电子在能量和俯仰角散射方面的一般影响。在辐射带区域普遍存在的哨声波在电子的传输、加速和损失中发挥着重要作用。观察到的哨声具有各种特征，有时是光滑的和无结构的，但有时被观察到是突发的和有结构的。结构化和突发性排放通常被称为合唱。了解波在辐射带区域相对论电子群形成中所起的作用是空间气象研究的关键，因为这些电子可能对卫星产生有害影响。这里的研究计划使用第一原理，自洽的模拟方法来理解关于甚低频哨声波的起源和磁层内等离子体的能量的基本问题。

This project will use a two-dimensional electromagnetic Darwin particle-in-cell simulation determine self-consistently how whistler waves are generated in the magnetosphere for a variety of conditions and to understand the ensuing wave-particle interactions. Non-linear wave-particle and wave-wave interactions are important aspects of this problem necessitating the use of particle in cell simulations. Recent observational and theoretical work has shown that whistler-mode waves can propagate obliquely with respect to the ambient magnetic field, so a multidimensional approach is required. The simulations will be run on a next-generation computational platform that will allow the inclusion of realistic parameters for the radiation belt region and will be used in close coordination with observed wave and particle data to study the growth, amplitudes, and wave propagation characteristics of whistler waves and for chorus waves, the formation of their structured spectra, and the general effects whistlers have on electrons in terms of energization and pitch angle scattering.Whistler waves, which are ubiquitous in the radiation belt region, play a major role in the transport, acceleration and loss of electrons. Whistlers are observed with a variety of characteristics and are sometimes smooth and unstructured, but other times are observed as bursty and structured. The structured and bursty types of emissions are commonly referred to as chorus. Understanding the role waves play in the formation of relativistic electron populations in the radiation belt region is key to space weather studies because of the deleterious effects these electrons can have on satellites. The research program here uses a first principles, self-consistent simulation approach to understand the fundamental problem concerning the origin of VLF whistler waves and the energization of inner-magnetospheric plasmas.