地球磁尾的电场模式  

THE CONVECTION ELECTRIC FIELD MODEL IN THE MAGNETOSPHERE

作　　者：张天辉[1] 徐荣栏[1] 李磊[1] 

机构地区：[1]中国科学院空间科学和应用研究中心,北京100080

出　　处：《空间科学学报》2002年第3期220-226,共7页Chinese Journal of Space Science

摘　　要：地球磁层中的电场是磁层等离子体运动的主要驱动力.目前常用的磁层电场为均匀晨昏电场和投影电场.本文假定磁力线为电场的等位线,地球电离层电场看做磁层电场沿磁力线在电离层的投影.利用Tsyganenko磁场模式（T89）,沿磁力线把电离层电场投影到磁尾,得到了一个新的磁层电场模式,文中对偶极磁场和T89磁场模式下的投影场作了比较,说明本模式突破了偶极磁场的局限。Taking the magnetic field lines as the equipotential lines, the convection field in the polar region at the ionospheric heights can be mapped into the magnetosphere where the electric field play a key role in various physical phenomena. To do this, a convection electric field in polar region and a magnetic model of magnetosphere are needed. In this paper, Volland's convection electric field model in the polar region and Tsyganenko's magnetic field model (T89) are used. It's not surprising that the electric field mapped from polar region is not a uniform dawn-dusk field. The results indicate that only in the distant magnetotail, the convection electric field can be considered as uniform dawn-dusk electric field. While, in the other region, there is not only the dawn-dusk electric field (Ey) but also the Ex and Ez. There exist three different regions in the magnetotail whose convection electric field has different characters. These characters are discussed. Generally, the dawn-dusk electric field become stronger and stronger when going from the distant magnetotail to the region near the earth. On the other hand, the electric field is stronger near the dawn and dusk magnetopause boundary than in the mid-plane.

关 键 词：地球磁尾 极区电场 磁尾电场 对流电场 投影电场 

分 类 号：P353[天文地球—空间物理学]