地球磁层对太阳风动压脉冲结构响应的研究进展

Progress in the Studies on Earth's Magnetospheric Responses to the Solar Wind Dynamic Pressure Pulses

综述了近年来国内外关于磁层对太阳风动压脉冲结构多时空尺度响应的观测结果以及物理模型。另外报道TC-1卫星在近地磁尾等离子片区观测的激波直接驱动磁尾等离子体片等离子体振动增强的新现象,并利用GOES飞船、LANL系列飞船,以及地磁数据,分析了该现象发生时地球同步轨道和地面对动压脉冲结构的响应。

The solar wind dynamic pressure pulses（DPPs） are a kind of important interplanetary small-scale disturbance structure.When it interacts with the magnetosphere,it will cause global strong disturbances in the magnetosphere-ionosphere coupling system that affect almost all major plasma regions and current systems in the magnetosphere and ionosphere.In this paper, the recent progress in the studies on the responses of the magnetosphere in multiple spatial and temporal scale to the solar wind dynamic pressure pulses is summarized,focused on the observations and the physical models.In addition,we report the new observations of TC-1,when the spacecraft is located in the near-Earth magnetotail plasma sheet,that the interplanetary shock directly drives the enhancements of the plasma oscillations in the magnetotail plasma sheet.The shocks are observed by WIND on November 07,2004.Prior to and after the shock,the IMF is either weakly southward or northward.The responses of the plasma sheet to the two shocks are intense and much similar.When the shock interacts with the magnetosphere,the magnetic field impulsively increases 12 min after the geomagnetic field sudden impulse（SI） judged from the Sym-H index change,and the magnetic field line is stretched.On the other hand,all of the ion density,the ion temperature,and the velocity of ion flow in the plasma sheet increase. Interestingly,quasi-periodical oscillations of the ion flow are suddenly enhanced,and the plasma flow is basically perpendicular to the local magnetic field.The responses of the magnetic field and the plasma are nearly simultaneous.The responses in the plasma sheet are probably caused by the lateral compression due to the dynamic pressure enhancement downstream the shock when the shock propagates antisunward in the magnetosheath.