极地研究2016，Vol.28Issue(1)：11-18,8.DOI:10.13679/j.jdyj.2016.1.011
径向行星际磁场下的场向电流统计学研究
STATISTICAL RESEARCH OF FIELD-ALIGNED CURRENTS UNDER RADIAL INTERPLANETARY MAGNETIC FIELDS
摘要
Abstract
The characteristics of field-aligned currents ( FACs) and the related physical quantities under radial interplan-etary magnetic field ( RIMF) from 2001 to 2009 were investigated .Statistical analysis and comparison with FACs under normal conditions were performed using CHAllenging Minisatellite Payload ( CHAMP) data.The results showed that the intensity of noon FACs has clear dependence on the dipole tilt angle under normal conditions and that the ratio between summer and winter is about 3; however , the dependence disappears under RIMFs and the ratio decreases to 2.The magnitude of the interplanetary magnetic field (IMF), the merging electric field, solar wind dynamic pressure , and the auroral electrojet ( AE ) index decrease , while the disturbance storm time ( Dst ) index remains almost stable under RIMFs .The merging electric field is a controlling factor of FACs under normal conditions, but the control effect disappears during RIMFs .In the Northern Hemisphere , the intensity of FACs under IMF Bx <0 conditions is larger than that under IMF Bx >0 conditions ( the situation is the converse in the Southern Hemisphere ) .Although the intensity of FACs under normal conditions is greater than that under RIMFs , the probability that the density of FACs under RIMFs is greater than the yearly average is about 0.2, and some geomagnetic disturbances , such as substorms , still occur under RIMFs .关键词
场向电流/径向行星际磁场/重联电场Key words
field-aligned currents/radial interplanetary magnetic fields/merging electric field引用本文复制引用
曹雪,刘丁维,黄韬,张科灯..径向行星际磁场下的场向电流统计学研究[J].极地研究,2016,28(1):11-18,8.基金项目
国家自然科学基金(41222030)资助 （41222030）
