磁尾等离子体片边界层场向电流与行星际磁场时钟角的关系  

The Relations between the Occurrence Frequency of FACs in the Plasma Sheet Boundary Layers and IMF Clock Angle

作　　者：程征伟[1] 史建魁[1] 刘振兴[1] 

机构地区：[1]空间天气学国家重点实验室,中国科学院空间科学与应用研究中心,北京100190

出　　处：《科学技术与工程》2012年第10期2272-2275,共4页Science Technology and Engineering

基　　金：国家自然科学基金(40804031;41074114;40921063)项目;国家重点实验专项基金资助

摘　　要：根据ClusterII卫星的探测数据,对1 839个磁尾等离子体片边界层场向电流事件与行星际磁场(IMF)时钟角Φ的关系进行了统计分析。结果显示等离子体片边界层场向电流的发生率明显受到IMF时钟角的调控:当0°<|Ф|<90°,场向电流发生率随IMF时钟角的变化曲线为一"V"型结构。当90°<Ф<180°时场向电流发生率保持在很高的水平上;当-180°<Ф<-90°时,场向电流的发生率先减小后增大,其拐点在Ф=-130°附近。这说明场向电流不仅受行星际Bz的影响,也受行星际磁场By的影响。The relationship between the occurrence frequency of field-aligned currents （FACs） at the plasma sheet boundary layers （PSBLs） in magnetotail and the interplanetary magnetic field （IMF） clock angle 6b using 1 839 FACs cases observed by the ClusterII satellites is analyzed. The main results indicated the followings： When 0°〈｜φ}〈90°, the occurrence frequency of FACs varied with the IMF clock angle as a ＂ V＂ structure; When 90°〈φ〈180°, the occurrence frequency of FACs were all in very high levels. When -180°〈φ〈-90°~, the occurrence frequency of FACs decreased firstly and then increased, it turned at φ=-130°. The results indicate that not only IMF Bx but also IMF By controlled the occurrence frequency of FACs.

关 键 词：场向电流 等离子体片边界层 IMF时钟角 

分 类 号：P353.2[天文地球—空间物理学]