Study of substorm simulation

对流是了解地球空间结构和磁层-电离层(M-I)系统中观测到的扰动的最基本过程。在本研究中，将全球对流系统在真实拓扑下的自洽位形视为一个复合系统。通过分析磁流体力学(MHD)模拟得到的数值结果，基于M-I耦合格式进行了研究，保证了整个系统在BV(磁场和速度)模式下的自洽。在M-I耦合方案中强调，对流和场向电流(FAC)是表征开放磁层的同一物理过程的不同方面。在这项研究中，特别关注驱动FAC系统的能源供应(发电机)过程。在对流系统中，发电机必须由剪切运动和等离子体布居状态共同构成，才能稳定地驱动对流。在电离层观察到的对流模式也是实现全球自我和谐的表现。将这些概念应用于地球空间研究的一个主要办法是考虑M-I系统在对给定的太阳风条件作出反应时如何调整可压缩磁层和不可压缩电离层之间的相对运动。上述原理也适用于亚暴等扰动现象的研究，以及通量转移事件(FTE)、突然启动(SC)和西塔极光等明显独特过程的研究。最后，试图将亚暴理解为行星际磁场(IMF)条件下增强对流的延伸。

Convection is the most fundamental process in understanding the structure of geospace and disturbances observed in the magnetosphere-ionosphere (M-I) system. In this study, a self-consistent configuration of the global convection system is considered under the real topology as a compound system. Investigations are made based on the M-I coupling scheme by analyzing numerical results obtained from magnetohydrodynamic (MHD) simulations which guarantee the self-consistency in the whole system under the BV (magnetic field and velocity) paradigm. It is emphasized in the M-I coupling scheme that convection and field-aligned current (FAC) are different aspects of same physical process characterizing the open magnetosphere. Special attention is given in this study to the energy supplying (dynamo) process that drives the FAC system. In the convection system, the dynamo must be constructed from shear motion together with plasma population regimes to steadily drive the convection. Convection patterns observed in the ionosphere are also the manifestation of achievement in global self-consistency. A primary approach to apply these concepts to the study of geospace is to consider how the M-I system adjusts the relative motion between the compressible magnetosphere and the incompressible ionosphere when responding to given solar-wind conditions. The above principle is also applicable for the study of disturbance phenomena such as the substorm as well as for the study of apparently unique processes such as the flux transfer event (FTE), the sudden commencement (SC), and the theta aurora. Finally, an attempt is made to understand the substorm as the extension of enhanced convection under the southward interplanetary magnetic field (IMF) condition.