GEM: Turbulence and Structure in the Magnetospheric Cusps: Cluster Spacecraft Observations and Numerical Simulations

该项目的主要目标是了解高空尖点中结构、边界和低频湍流的形成，并研究由于结构、磁重联和低频湍流的运动而引起的粒子加速。调查将使用几年的星团卫星数据，并辅以磁鞘中的双星星星卫星数据。 数据分析方法包括方差分析技术、将观测值转换为deHoffman Teller参考系、使用Walen关系、多航天器方法以及快速傅立叶变换和小波分析等频谱分析方法。 数据分析结果将与尖点几何形状的三维高分辨率MHD模拟进行比较。 可以在模拟箱中进行虚拟航天器测量，并与卫星数据进行比较。 模拟还将使用测试粒子。这项研究将涉及几个具体专题：（1）尖点中反磁空腔和其它边界的形成，（2）开尔文-亥姆霍兹模和重联作为尖点中低频湍流发生器的作用，（3）鞘湍流对尖点湍流的影响，以及（4）（i）反磁空腔的运动，（ii）重联，和（iii）低频波湍流对尖点中粒子加速的影响。该项目通过将安柏瑞德航空大学（ERAU）的本科生纳入夏季研究计划，将研究和教育结合起来。 PI还将创建一个项目网站，使ERAU的本科生（以及更广泛的受众）能够轻松有趣地熟悉该项目并通过该项目学习空间科学。ERAU正在促进代表性不足的群体的平等机会，PI将在为该项目提名学生时遵循这一传统。

The primary goal of this project is to understand the formation of structure, boundaries and low frequency turbulence in the high-altitude cusp and to study particle acceleration due to the motion of the structures, magnetic reconnection and low frequency turbulence. The investigation will use several years of Cluster satellite data complemented with Double Star satellite data in the magnetosheath. Data analysis methods include variance analysis techniques, transforming observations into the deHoffman Teller frame of reference, use of the Walen relation, multi-spacecraft methods, and spectral analysis methods such as Fast Fourier Transform and Wavelet analysis. The data analysis results will be compared with three-dimensional high-resolution MHD simulations in the cusp geometry. Virtual spacecraft measurements can be taken in the simulation box and compared with satellite data. The simulations will also use test particles. The study will address several specific topics: (1) The formation of diamagnetic cavities and other boundaries in the cusp, (2) the role of Kelvin-Helmholtz modes and reconnection as generators of low frequency turbulence in the cusp, (3) the effect of sheath turbulence on cusp turbulence, and (4) the effect of (i) the motion of the diamagnetic cavities, (ii) reconnection, and (iii) low frequency wave turbulence on particle acceleration in the cusp. The project integrates research and education by including undergraduate students of Embry-Riddle Aeronautical University (ERAU) in a summer research program. The PI will also generate a project website that makes it easy and interesting for the undergraduate students in ERAU (but also for a broader audience) to get familiar with the project and learn space science through it. The ERAU is promoting equal opportunities for the underrepresented groups and the PI will follow this tradition when nominating students for this project.