Kinetic Study of Flux Transfer Events Enabled by Petascale Computing

该项目将使用计算机模拟来研究地球日侧磁层顶通量转移事件(FTE)的形成和演化。模拟的主要工具将是三维混合模拟(将电子视为流体的离子的动力学粒子处理)，但在少数情况下也将使用完全的粒子在单元(PIC)模拟，以研究FTE事件期间的电子加速问题。混合模拟的结果将与全球MHD模拟进行比较，以确定离子动力学效应的引入如何改变FTE事件的动力学。结果还将与各种卫星任务(主要是NASA的GeoTail和欧洲航天局的星团任务)的观测结果进行比较。通量转移事件是将能量从太阳风传输到磁层的一类重要的磁重联事件。理解FTE事件需要在真实的几何体中进行全局模拟，并具有真实的(和不断变化的)太阳风条件。只是在过去的几年里，高性能计算能力才达到了进行这些模拟所必需的千万亿次浮点运算规模。这项工作的结果有可能改变我们对这些事件发生的方式和原因的理解。该项目具有强大的教育效益，因为研究生将参与使用最先进的计算机代码和最先进的可视化工具。该项目还包括将研究结果用于公共宣传活动，特别是针对拥有大量社会经济贫困学生的K-12学校。

This project will use computer simulations to study the formation and evolution of flux transfer events (FTEs) at the dayside magnetopause of the Earth. The primary tool for the simulations will be 3-Dimensional hybrid simulations (kinetic particle treatment of ions with electrons treated as a fluid) but the will also use full particle-in-cell (PIC) simulations in a few cases to examine issues regarding electron acceleration during FTE events. Results from the hybrid simulations will be compared with global MHD simulations to determine how the introduction of ion kinetic effects changes the dynamics of an FTE event. The results will also be compared with observations from a variety of satellite missions (primarily NASA's Geotail and the European Space Agency's Cluster mission).Flux transfer events are an important class of magnetic reconnection events that transport energy from the solar wind into the magnetosphere. Understanding FTE events requires global simulations in a realistic geometry and with realistic (and changing) solar wind conditions. It is only in the past few years that high performance computing capabilities have reached the petaflops scale that is necessary to do these simulations. The results from this work have the potential to transform our understanding of how and why these events occur. The project has strong educational benefits because graduate students will be involved with using the state-of-the-art computer codes and the state-of-the-art visualization tools. The project also includes using the results from the research in public outreach activities, particularly targeted toward K-12 schools with large, socio-economically disadvantaged students.