Collaborative Research: GEM--Global Propagation Characteristics of Electromagnetic Ion Cyclotron Waves

该项目的重点是研究近地空间环境中电磁离子回旋波(EMIC)的产生、传播和耗散。磁波是由等离子体与地球磁场相互作用而产生的。这些波对范艾伦辐射带中粒子的能量和损失都起着重要的作用。由于辐射带与卫星运行的区域重叠，因此了解可能改变其强度的因素是预测空间天气影响的一个重要方面。该项目将使用观测和数值模拟相结合的方法来研究EMIC波动力学。该领域以前的大多数建模都使用光线跟踪方法。本项目采用了一种新颖的方法，即使用全波模型来模拟波浪动力学。该项目将支持担任PI的年轻女科学家的努力。它还将为博士生提供支持。研究人员还将计划通过与国家等离子体物理和聚变能源科学本科生奖学金计划合作，为本科生提供参与研究的机会。更具体地说，该项目涉及以下问题：(A)赤道产生的电磁波如何到达地面？(B)电磁波的传播如何受到地磁活动的影响？(C)磁层/电离层参数和波法向角对电磁波从磁层到电离层的传播有何相对贡献？为了实现这一目标，研究人员计划使用最近开发的具有真实等离子体参数的2D全波代码进行全波模拟。我们还将分析Van Allen探测器、THEMIS和GOES卫星最近对这些波的观测，并将它们与地面磁力计网络的观测结果进行比较。

The focus of project is to investigate the creation, propagation, and dissipation electromagnetic ion cyclotron waves (EMIC) in the near-Earth space environment. EMIC waves are created by the interaction of plasma with the Earth's magnetic field. These waves play an important role in both the energization and loss of particles in the Van Allen radiation belts. Since the radiation belts overlap the region where satellites operate understanding the factors that can change their intensity is an important aspect of predicting space weather impacts. This project will use a combination of observations and numerical modeling to address EMIC wave dynamics. Most previous modeling in this area has used ray-tracing methods. This project takes the novel approach of using a full wave model to simulate the wave dynamics. The project will support the efforts of young female scientist who is serving as the PI. It will also provide support to PhD graduate student. The investigators will also plan to provide opportunities for undergraduates to participate in the research through partnership with National Undergraduate Fellowship Program in Plasma Physics and Fusion Energy Sciences program. More specifically this project addresses the following questions; (a) How do equatorially generated EMIC waves reach the ground?; (b) How is EMIC wave propagation affected by geomagnetic activity?; and (c) What are the relative contributions of magnetospheric/ionospheric parameters and wave normal angle to EMIC wave propagation from the magnetosphere to the ionosphere? To achieve this goal, the investigators plan to perform full-wave simulations employing recently developed 2D full-wave code with realistic plasma parameters. We will also analyze recent observations of these waves by Van Allen Probes, THEMIS and GOES satellites and compare them with observations from the ground magnetometer network.