磁层顶通量传输事件的经验重构  

Empirical Reconstruction of Flux Transfer Events at the Magnetopause

作　　者：李照宇 陈涛 LI Zhaoyu;CHEN Tao(State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190;University of Chinese Academy of Sciences, Beijing 100049)

机构地区：[1]中国科学院国家空间科学中心空间天气学国家重点实验室,北京100190 [2]中国科学院大学,北京100049

出　　处：《空间科学学报》2017年第6期675-689,共15页Chinese Journal of Space Science

基　　金：国家自然科学基金项目(40774081);空间天气学国家重点实验室专项基金项目;中国科学院国家空间中心项目(CAS-NSSC-135)共同资助

摘　　要：在地球磁层顶附近观测到的通量传输事件(Flux Transfer Event,FTE)—般被认为是瞬态局域磁重联的产物,是太阳风质量、动量和能量进入地球内磁层的重要通道.重构FTE的磁场结构可促进对其形成、演化过程及其与周围等离子体环境相互作用的理解.Grad-Shafranov重构法和磁通量绳拟合法等传统磁场重构方法适用于满足特定物理条件的磁场结构.基于平面线性插值原理,设计了一种不受具体物理条件限定的二维FTE磁场结构重构法.模型测试以及对THEMIS和Cluster卫星簇分别观测到的两个FTE的实际应用表明,在合适的多卫星位形条件下,该方法能快速有效重构出FTE的磁场空间分布,有助于推测FTE的磁场线位形,理解卫星测量数据的时间变化,以及分析等离子体物理量相对于FTE的磁场空间分布特征.Flux Transfer Events （FTEs） observed at the Earth＇s magnetopause are generally be- lieved to be products of transient and patchy magnetic reconnection processes, serving as linkage channels between solar wind and Earth＇s magnetosphere and therefore playing a crucial role in the exchange of mass, momentum, and energy between these two regions. Magnetic field reconstruction techniques are useful for better understanding FTE＇s formation and evolution and its interaction with surrounding environment. Traditional techniques such as Grad-Shafranov reconstruction and FTE model fitting methods, however, are confined to specific physical conditions. A new multi-point method applicable to two-dimensional FTEs in various physical condition is devised based on plane linear interpolation. The applications to two FTEs observed by THEMIS and Cluster show that themethod can quickly and efficiently reconstruct the spatial distribution of the magnetic field structure, and will help to infer the magnetic field line configurations, understand the temporal variation of measured data and analyze the spatial distribution characteristic of plasma parameters relative to the magnetic field.

关 键 词：通量传输事件 磁层顶 经验重构 多点分析 

分 类 号：P353[天文地球—空间物理学]