摘要
等离子体泡是赤道区电离层常见的密度耗空结构,同时伴随着背景磁场的增强和垂直背景磁场方向上的扰动,这些扰动具有阿尔芬波的特征。本文利用Swarm卫星的标量、矢量磁场以及等离子体观测数据,考察了等离子体泡产生的磁场扰动信号特征,发现磁场强度和平均场向分量的增强均与等离子体泡密度下降有较强的负相关性,说明磁场标量和矢量(平均场向分量)数据都可以用来识别等离子体泡。由于Swarm卫星的标量磁场数据噪声明显低于矢量磁场数据,利用标量磁场数据可以提高等离子体泡的识别率,识别更多波动较小的等离子体泡。
Equatorial Plasma Bubbles(EPBs)are density depleted structures in the equatorial ionosphere,accompanied by the enhanced magnetic field strength,and fluctuations in the directions transverse to the main field,which have Alfvenic wave signatures.Utilizing the scalar,vector magnetic field,and plasma data from the Swarm mission,the magnetic signatures related with EPB are investigated.It is found that the changes both in the magnetic field strength and the component parallel with the main field are anti-correlated with the density changes inside EPBs,suggesting both the scalar and vector magnetic field data could be used to identify EPSs.Comparing the results of EPB identification using Swarm satellite scalar and vector magnetic field data products respectively,it is confirmed using the scalar data can increase the chance to identify EPBs,especially to find EPBs with relatively lower field fluctuations,since the noise level of the Swarm scalar magnetometer is about one order of magnitude lower than that of the vector magnetometer.
作者
李博
李磊
苟晓晨
周斌
LI Bo;LI Lei;GOU Xiaochen;ZHOU Bin(State Key Laboratory of Space Weather,National Space Science Center,Chinese Academy of Sciences,Beijing 100190;University of Chinese Academy of Sciences,Beijing 100049)
出处
《空间科学学报》
CAS
CSCD
北大核心
2022年第2期232-239,共8页
Chinese Journal of Space Science
基金
国家自然科学基金项目(41904147)
国家重点研发计划项目(2018YFC1503503)共同资助。
关键词
电离层
等离子体泡
磁场扰动
标量磁场
矢量磁场
Ionosphere
Equatorial plasma bubble
Magnetic field fluctuation
Scalar magnetic field
Vector magnetic field
