Studies on magnetospheric boundary processes based on magnetic field and aurora observation in the northern and southern polar caps

为了弄清太阳风与地球磁层之间的相互作用，利用位于南极大陆内部的6个无人自动地球物理观测站对磁层边界过程进行了研究。结合AGO设备记录的数据，如磁强计、极光成像仪、riometer和甚低频接收器，航天器获得的太阳风和太阳活动数据以及Syowa站的高频雷达数据，进行了综合分析。包括一些重要和新发现的结果如下：1）缀合物TCV发现了与TCV有关的电离层瞬变扰动，表明这种扰动是由三维电流系统和极光粒子沉降引起的F区非线性过程的结果; 3）MIE的自动探测算法（磁脉冲事件）和TD（切向不连续性）。使用这些算法，发现MIE和TD出现在季节变化中具有相关性。4）发展了一种利用单颗航天器获得的数据计算TD到达时间的技术。5）考虑磁层-电离层耦合过程中的共轭条件，建立了TCV现象的定量模型。6）通过三维MHD模拟研究了TCV的电流产生机制。结果成功地再现了典型的TCV现象。

In order to clarify the interaction between the solar wind and the magnetosphere of the Earth, magnetospheric boundary processes were investigated, making use of 6 non-manned automatic geophysical observatories (AGO) located in the interior of the Antarctic Continent. Comprehensive analysis was carried out, combining data recorded by AGO equipments, such as magnetometers, aurora imagers, riometers and VLF receivers, and solar wind and solar activity data obtained by spacecrafts as well as HF radar data at Syowa station. Results including some important and new findings are as follows:1) Conjugate TCV (traveling convection vortices) events moving sunward in both hemispheres were found and its physical mechanisms were investigated in detail.2) Transient ionospheric disturbances relating to the TCV were found. It is shown that the disturbances are consequence of non-linear processes in F-region caused by 3-D current system and auroral particle precipitations.3) Automatic detection algorithms for MIE (magnetic impulse event) and for TD (tangential discontinuity) were developed successfully.Using these algorithms,it was found that occurences of MIE and TD show correlation in seasonal variation.4) A tecchnique to calculate the TD arrival time using data obtained by one spacecraft was developed.5) Quantitative model for TCV phenomena considering conjugate condition in the magnetosphere-ionosphere coupling processes was constructed.6) 3-D MHD simulation was conducted to understand the current generation mechanisms associated with TCV. The results succeeded in reproducing typical TCV phenomena.