空间科学学报2000，Vol.20Issue(2)：144-149,6.
大尺度场向电流的控制因素
DEPENDENCE OF FIELD-ALIGNED CURRENTS ON THE ORIENTATION OF THEINTERPLANETARY MAGNETIC FIELD
摘要
Abstract
Field-aligned currents (FACs) measured in the inner magnetosphere by theISEE-1 and -2 spacecraft are investigated as a function of theInterplanetary Magnetic Field (IMF) orientation and the level ofgeomagnetic activity, as indicated by the AL index. It is found that75% of the FACs observed are associated with southward IMF. Theremaining 25% occur during the period of IMF turning from southward tonorthward. Very few are associated with sustained intervals ofnorthward IMF. Approximately 75% of the FACs occur when the AL index is<-150 nT. The current intensity and density are higher for bothsouthward IMF and high geomagnetic activity. These results show thatthe occurrence of FACs within the inner magnetosphere is controlledmainly by the IMF, with the actual occurrence being a consequence ofenhanced electrodynamic coupling between the solar wind and themagnetosphere-ionosphere system.关键词
场向电流—行星际磁场—AL指数Key words
Field-aligned currents/Interplanetary magneticfield/AL index分类
天文与地球科学引用本文复制引用
焦维新,濮祖荫..大尺度场向电流的控制因素[J].空间科学学报,2000,20(2):144-149,6.基金项目
国家自然科学基金资助项目 49774248 （）
