磁宁静期磁尾爆发性整体流持续时间多点卫星研究

Multipoint analysis of the temporal scale of bursty bulk flow events during the quiet time of magnetotail

本文利用星簇CLUSTER的三颗卫星数据分析了磁宁静期磁尾爆发性整体流(BBFs,BurstyBulkFlows)的时间尺度,并与单个卫星的结果做了比较.事例研究表明,利用三颗卫星观测数据判断的BBFs的时间尺度比单个卫星的大一倍左右.对于三颗卫星观测到的同一个BBFs ,BBFs在晨昏方向上的摆动决定了CLUSTER的三个卫星观测到BBFs的先后次序.三颗卫星的观测也显示了BBFs的高度局域化特征.磁宁静期磁尾BBFs寿命的增大,使得BBFs携带的质量和能量的地向输运增加.这种地向输运增加的结果是:磁尾储存的能量得到较为平稳的释放,改变了亚暴起始产生的时间,为解决磁层压力平衡矛盾(PBI,PressureBalanceInconsistency)问题提供了新的思路.

A series of Bursty Bulk Flow events (BBFs) were observed by CLUSTER satellites during the quite time of the magnetotail. By studying the data of multi-satellites of CLUSTER, we got some results about the time scale of BBFs which is different from that obtained from single satellite. The temporal scale of multi-satellites is about twice that of single satellite. Flapping of BBFs in the dusk-dawn direction determined the temporal order of observation of BBFs of three CLUSTER satellites. The localization of BBFs is also confirmed by simultaneous multi-satellite observations. The longer duration of BBFs during the quiet time of magnetotail enhances the earthward transport of mass and energy and changes the onset of the substorm. Our study also provided a new idea to solve the Pressure Balance Inconsistency (PBI).