磁层快速对流事件的多点卫星联合观测

Multipoint analysis of the rapid convection event

本文利用星簇Cluster的三颗卫星(C1,C3和C4)在2001年和2002年的数据,研究了快速对流事件(RCE,Rapid Convection Event)及其与亚暴的关系.结果显示单点卫星对RCE的观测,不能反映磁尾RCE的真实情况.在2002年7月25日发生的一次RCE事件,C1和C3观测到这次RCE,C4却没有观测到.在三颗卫星联合观测到的306次RCE中,C1观测到215次,C3观测到266次,C4观测到227次.统计研究表明,单点卫星观测到的RCE的平均时间也不能准确反映磁层内的RCE.由此推论在整个中心等离子体片内,快速对流事件所承担的能量和磁通量的输运量,可能远大于单点卫星观测给出的结果.用速度来定义的磁尾爆发性整体流(BBF,Bursty Bulk Flow)与亚暴的关系,比用磁通量定义的RCE与亚暴的关系要更加紧密.

Basing on the data from three satellites of Cluster （C1, C3 and C4） in the years of 2001 and 2002, we examine the relationship between the rapid convection event （RCE） and substorm. The observation of RCE measured by single satellite is not exactly what happened in the magnetotail. Both C1 and C3 observed the event occurring on July 25, 2002, but CA did not. Among the 306 RCEs jointly measured by three satellites, 215 ones were observed by C1. C3 and CA obtained 266 and 227 ones respectively. The average duration of RCE in the magnetosphere can＇t be really represented by the outcome surveyed by single satellite. So our analysis has shown that RCE transports more fractions of energy and magnetic flux than what had calculated by single satellite in the central plasma sheet. Relationship between Bursty Bulk Flow （BBF） termed by the velocity and substorm is more close than that of RCE defined by the magnetic flux.