A Three-Dimensional Global Hybrid Simulation Study of Magnetic Reconnection at the Dayside Magnetopause

磁重联是将太阳风的质量、动量和能量转移到地球磁层中起重要作用的基本过程。关于磁层顶边界层重联的微观和中尺度特征的基本问题还没有得到充分的了解。该项目将使用三维全球混合等离子体模型来研究磁层顶的磁重联。混合代码将电子视为流体，但包括离子的完整粒子动力学。该代码能够在从离子陀螺周期到日侧对流时间尺度，从离子拉莫尔半径到全球尺度长度的广泛范围内解析等离子体物理。本项目的主要任务是：(1)确定日侧磁层顶磁重联的三维结构；(2)确定磁层顶磁重联中的磁场和等离子体特性以及磁传递事件（FTEs）的演化；(3)研究不同位置磁重联事件中相应的离子动力学和速度分布。(4)研究磁场主要为反平行时发生的重联与存在强引导场时发生的重联（也称为分量重联）之间的差异。这项研究将有助于我们对全球磁层中磁重联的三维、多尺度物理学的理解，并将提高我们对地球空间动力学和结构特性的认识。三维混合建模的努力也将在磁层、天体物理学和实验室等离子体物理学的其他主题中有更广泛的应用。这项研究将包括一名研究生，它还将为国家科学基金会的目标做出贡献，即为研究和教育开发和维护尖端的国家计算和信息基础设施

Magnetic reconnection is a fundamental process that plays an important role in the transfer of the solar wind mass, momentum, and energy into Earth's magnetosphere. Fundamental issues on the micro- and mesoscale characteristics of reconnection in the magnetopause boundary layer are not adequately understood. This project will use a 3-D global hybrid plasma model to investigate magnetic reconnection at the magnetopause. The hybrid code treats electrons as a fluid, but includes full particle kinetics of ions. The code and is capable of resolving the plasma physics in a broad range from ion gyro-period to the dayside convection time scale, and from the ion Larmor radius to the global scale lengths. The primary tasks of this project are: (1) determination of the 3-D structure of magnetic reconnection at the dayside magnetopause, (2) determination of the magnetic field and plasma properties and evolution of flux transfer events (FTEs) in the magnetopause reconnection, (3) investigation of the corresponding ion dynamics and velocity distributions in reconnection events at various locations, and (4) investigation of the differences between reconnection that occurs when the magnetic fields are primarily anti-parallel and reconnection that occurs when there is a strong guide field (also know as component reconnection). The study will contribute to our understanding of 3-D, multi-scale physics of magnetic reconnection in the global magnetosphere and will improve our knowledge of the dynamical and structural properties of geospace. The 3-D hybrid modeling efforts will also have broader applications in other topics of magnetospheric, astrophysical, and laboratory plasma physics. The study will include a graduate student and it will also contribute to the National Science Foundation's goal of developing and maintaining cutting edge national computing and information infrastructure for research and education