空间科学学报2018，Vol.38Issue(3)：315-331,17.DOI:10.11728/cjss2018.03.315
利用THEMIS卫星观测结果分析亚暴期间等离子体片尾向膨胀
Tailward Expansion of the Plasma Sheet during a Substorm Using THEMIS Observations
摘要
Abstract
A moderately intense substorm from 10:40UT to 12:10UT on 13 March 2008 observed by THEMIS probes is examined to analyze the global evolution of the substorm in the magnetotail.During this substorm,five THEMIS probes are arranged along the x-axis in the vicinity of the midnight,from the radical distance of about 8.7 to 13.2 Re.Magnetic field dipolarization and plasma sheet expansions are all observed by different probes after the substorm onset.The average velocity of the plasma sheet expansions is about 140 km·s-1.Two types of dipolarization are detected in this substorm.One type is dipolarization front which is associated with the Bursty Bulk Flow (BBF).The other type is global dipolarization which is associated with plasma sheet expansions.The occurrenceof Pi2 pulsation can be observed at low,medium and high latitudes 7 minutes later from the substrom onset.The amplitude of Pi2 pulsation gradually increases with the increase of latitude.The ion bulk velocity in the substorm event is mainly caused by the ion drift velocity,and the measured electric field is the induced electric field generated by the change of the local magnetic flux.关键词
亚暴/磁场偶极化/等离子体片膨胀/Pi2脉动/电漂移速度Key words
Substorm/Magnetic dipolarization/Plasma sheet expansion/Pi2/pulsation/Electric drift velocity分类
天文与地球科学引用本文复制引用
任年,沈超,马永辉..利用THEMIS卫星观测结果分析亚暴期间等离子体片尾向膨胀[J].空间科学学报,2018,38(3):315-331,17.基金项目
国家自然科学基金项目资助(41231066) （41231066）
