地球磁尾中不同类型磁结构的磁螺度演化特征  

EVOLUTION OF THE MAGNETIC HELICITY OF VARIOUS MAGNETIC STRUCTURES IN THE MAGNETOTAIL

作　　者：崔海龙[1] 金曙平[1] 

机构地区：[1]中国科学技术大学地球与空间科学系,合肥230026

出　　处：《地球物理学报》2002年第2期149-159,共11页Chinese Journal of Geophysics

基　　金：~~

摘　　要：在二维三分量MHD数值模拟的基础上 ,对地球磁尾不同类型磁结构的形成作磁螺度分析 .研究表明 ,对于由晨昏电场产生的磁尾驱动重联过程 ,通过系统边界输运的磁螺度通量是引起系统总磁螺度变化的直接原因 .不同的初始磁螺度密度分布和磁螺度通量输运 ,可以引起中性片区域磁螺度密度分布的不同演化 ,从而导致具有不同拓扑位形磁结构的形成 .On the basis of the former two dimensions and three components MHD numerical simulation , this paper analyses evolution of the magnetic helicity of various magnetic structures in the magnetotail. The results illustrate that in the driven magnetic reconnection process generated by the dawn dusk electric field in the magnetotail, the transportation of magnetic helicity flux via the boundaries of the system is the direct cause of the change of the total magnetic helicity in the system. The various initial distributions of magnetic helicity density and the transportation of magnetic helicity flux may lead to various evolutions of magnetic helicity density in the neutral sheet region, and could result in the formation of various magnetic structures. [

关 键 词：磁螺度 磁螺度通量 驱动重联 磁结构 地球磁尾 晨昏电场 

分 类 号：P353[天文地球—空间物理学]