A preliminary exploration of the mechanism for the occurrence of two types of various magnetic structures in the magnetotail  

作　　者：JIN Shuping HU Xianpeng GUI Hailong LIU Zhenxing PU Zuyin B.Wilken 

机构地区：[1]Department of Earth and Space Science,University of Science and Technology of China,Hefei 230026,China [2]Center for Space Sciences and Application Research,Chinese Academy of Sciences,Beijing 100080,China [3]Department of Geophysics,Peking University,Beijing 100871,China [4]Max-Planck Institut fuer Aeronomie,D-37191 Katlanburg-Lindau,Germany

出　　处：《Chinese Science Bulletin》2001年第12期981-986,共6页

基　　金：This work was supported by the National Natural Science Foundation of China (Grant Nos. 49874035 and 49834040); and the Space Physics Fund of the First-rate University Program.

摘　　要：As well known, the magnetic cross-tail component By in the magnetotail is in direct proportion to the in-terplanetary magnetic field (IMF) By component. And the polarity of IMF and plasmoid / flux rope By components do indeed agree. This results indicate that the IMF By penetrates plasmoids and the magnetic structures must therefore be three-dimensional. In this note, the dynamical processes of magnetotail in the course of a substorm are studied using a MHD code with two-dimensions and three components on the basis of two types of initial equilibrium solutions of the quiet magnetotail. The numerical results of two cases illustrate various features of time evolution of By component that correspond to two kinds of plasmoid-like structures: one is associated with a flux rope core and the other resembles a 'closed loop' plamoid. Therefore, the occurrence of various magnetic structures in the magnetotail might be related to nonsteady driven reconnection with different distributions of the By component.As well known, the magnetic cross-tail component By in the magnetotail is in direct proportion to the interplanetary magnetic field (IMF) B y component. And the polarity of IMF and plasmoid / flux rope B y components do indeed agree. This results indicate that the IMF B y penetrates plasmoids and the magnetic structures must therefore be three-dimensional. In this note, the dynamical processes of magnetotail in the course of a substorm are studied using a MHD code with two-dimensions and three components on the basis of two types of initial equilibrium solutions of the quiet magnetotail. The numerical results of two cases illustrate various features of time evolution of By component that correspond to two kinds of plasmoid-like structures: one is associated with a flux rope core and the other resembles a “closed loop” plamoid. Therefore, the occurrence of various magnetic structures in the magnetotail might be related to nonsteady driven reconnection with different distributions of the B y component.

关 键 词：magnetospheric SUBSTORM MAGNETIC cross-tail component By plasmoid-like structures nonsteady MAGNETIC reconnection. 

分 类 号：P353[天文地球—空间物理学]