太阳风一磁层相互作用的磁流体力学数值模拟研究

MHD Simulations on the Interaction of the Solar Wind With the Magnetosphere

磁层位于地球空间的最外层,太阳风与磁层的相互作用是空间天气变化因果链中承上启下的关键环节,是揭示地球空间天气基本规律的关键科学课题.地球空间由于时变、多成分、多自由度的关联相互作用,使得传统的理论分析变得非常困难.数值模拟作为近几十年发展起来的一个新的研究手段,对地球空间的理论和应用研究产生了深刻的影响.国际上磁层的全球MHD数值模拟工作开始于20世纪70年代末,最初的研究局限于二维空间由于磁层内在的三维特性,20世纪80年代三维MHD数值模拟工作兴起.本文简要说明了三维全球磁层MHD(磁流体力学)研究的特点及现状,给出了三维全球磁层模型的基本框架,综述了行星际激波与磁层相互作用、大尺度电流体系、重联电压和越极电位、磁层顶K-H不稳定性等方面的太阳风-磁层相互作用的MHD数值模拟的研究进展.

The magnetosphere is outermost layer of the geospace. Interaction of the solar wind with the magnetosphere is one of the key links among the space weather chain process from the Sun to Earth, thus becomes one of the key issues in space weather study. The characteristics of the geospace, including time-dependent, multiple components, and non-linearity, make the traditional analytic study very difficult. Numerical simulations, as new means to investigate the coupling system, has played an important role in recent decades. The global MHD simulation about the magnetosphere started in 1970s, and limited to 2D initially. Since the intrinsic 3D characters of the magnetosphere, 3D MHD simulations thrived in 1980s. This paper briefly illustrates the characteristics of the 3D global magnetosphere MHD simulations, and their current status. The framework of the 3D global MHD magnetosphere simulation, and its application to the interaction of interplanetary shocks with the magnetosphere, large-scale current systems, reconnection voltage and cross polar potential drop,K-H instability in the magnetopause etc. are presented.