亚暴事件中磁尾多重等离子体团的数值研究(Ⅰ)  

A SIMULATION STUDY OF MULTIPLE PLASMOIDS IN THE MAGNETOTAIL DURING SUBSTORM EVENT(Ⅰ)

作　　者：金曙平[1] 马宁[1] 刘振兴[2] 濮祖荫[3] 宗秋刚[4] B.Wilken 

机构地区：[1]中国科学技术大学地球和空间科学系 [2]中国科学院空间科学与应用研究中心 [3]北京大学地球物理系 [4]中国科学院空间科学与应用研究中心北京,100080 [5]Max-Planck-InstitutfurAeronomie,D-37191Katlenburg-Lindau,Germany

出　　处：《地球物理学报》1997年第6期729-738,共10页Chinese Journal of Geophysics

基　　金：国家自然科学基金!49391400

摘　　要：GEOTAIL卫星于1994年1月15日亚暴期间，在深磁尾（x＝96RE）观测到多重等离子体团及与之相对应的高能离子爆，作者以宁静磁尾平衡位形为初态，考虑介质的可压缩性，数值研究亚暴期间磁尾动力学过程．计算结果展现了等离子体团间歇性形成及其运动发展过程．体现了强亚暴事件中储存于碰尾的能量，通过多重等离子体团的排放而逐渐释放的进程．数值结果还表明：持续施加于边界上的晨昏电场及由此引发的驱动重联是导致等离子体团准周期形成的主要因素．此外，作者还考察尾瓣内任一点磁场强度及其分量随时间的演化，它与行进压缩区（TCRs）的观测特征基本相符．During the substorm on January 15, 1994, GEOTAIL spacecraft found multiple plasmoids which were associated with quasi-periodic ion burstS in the deep tail. In thes report, the plasma dynamics in a long magnetotail is numerically investigated on the basis of initial like equilibrium configuration and tWo dimensional compressible MHD code. The numerical resultS illustrate intermittent formation of plasmoids and their inchon development processes. Thus, it may be concluded that a large amount of the energy stored in magnetotail are gradually dissipated by ejecting multiple plasmoids in the course of a substorm event. As shown in numerical results the driven reconnection caused by the electrical field imposed on the boundary leads to quasi-periodic generation of plasmoids. In addition, it has been demonstrated that the bine variation of magnetic field and itS components at a random point in the tail lobes is similar tO the observation signatures of Travelling Compression Regions (TCAs).

关 键 词：亚暴事件 等离子体团 驱动重联 磁尾 数值研究 

分 类 号：P352.4[天文地球—空间物理学]