摘要
本文利用同一经度(大约100°E)中低纬三台测高仪(普洱22.7°N,101.05°E,乐山29.6°N,103.75°E,张掖39.4°N,100.13°E)的观测数据,对2017年9月6号太阳耀斑爆发引起的强烈地磁暴期间的大尺度电离层行进式扰动(Large Scale Traveling Ionospheric Disturbances,LSTIDs)的传播特性进行了估计.本文首先对2017年9月2日—11日期间三站观测数据进行人工度量,获取电离层F2层临界频率(foF2).foF2在三站的变化结果表明在2017年9月8日21:00 BJT(BeiJing Time,BJT=UT+8)至9日03:00 BJT强磁暴恢复相期间存在大尺度电离层行进式扰动(LSTIDs),因此本文利用foF2在不同台站的互时延特征来分析并计算LSTIDs传播特性参数.研究结果表明:(1)磁暴期间,通过对电离层F2层临界频率(foF2)的观测,不同时刻期间处于不同纬度的台站其电离层响应是不同的,表现为出现不同形态的电离层正相暴和电离层负相暴;(2)此次磁暴期间(2017年9月8日19:00 BJT—9日05:00 BJT),利用三个处在不同纬度台站的foF2对磁暴响应的互延时,计算出LSTIDs水平传播速度在425~800 m/s范围之间,其波长大概在2200~4000 km之间.随着时间的推移其扰动周期延长,9月8日21:35 BJT—9日00:05 BJT期间周期约1.2 h,9日00:05 BJT开始扰动周期逐渐达至1.5 h;(3)LSTIDs具有从高纬度传向低纬度的传播特性,根据计算得出LSTIDs传播的方位角为181±0.2°,可确定磁暴引发的LSTIDs基本是朝赤道向传播的,与之前报道过关于磁暴诱发的LSTIDs传播特征基本一致.
In this study,ionograms recorded by three ionosondes(Puer,22.7°N,101.05°E,Leshan,29.6°N,103.75°E,and Zhangye,39.4°N,100.13°E)located about the longitude of 100°E,were used to investigate propagate characteristics of Large scale Traveling Ionospheric Disturbances(LSTIDs)induced by intense geomagnetic storm occurred on September 6,2017,which caused by solar flares.At first,critical frequency of the F2 layer(foF2)was scaled manually from ionograms recorded during September 2-11,2017.Results show that LSTIDS can be observed between 21:00 BJT(BeiJing Time,BJT=UT+8)on September 8 and 03:00 BJT on September 9 during the recovery phase of the intense geomagnetic storm.Moreover,this paper utilized mutual delay characteristics of foF2 at different latitude,the speed and direction of the propagation of LSTIDs were calculated.We found that(1)During the magnetic storm(2017-09-0819:00 BJT-0905:00 BJT),by observing the critical frequency(foF2)of the ionospheric F2 layer,the negative and positive phase of Ionospheric storm can be observed in this study.Its propagation characteristics are different and depend on latitudes;(2)The speed and horizontal wavelength of the present LSTIDs are 425~800 m/s and about 2200~4000 km,respectively.With the passage of time,the period of the disturbance was prolonged.The period on September 8th at 21:35 BJT-9th 00:05 BJT period was about 1.2 h.On the 9th at 00:05 BJT,the disturbance period gradually reached 1.5 h;(3)According to the propagation characteristics of LSTIDs from high latitudes to low latitudes,the azimuth of LSTIDs propagation was calculated to be 181±0.2°.Results show that the LSTID was almost propagating equatorward in this study,which is consistent with the existing literature about the propagation characteristics of the intense magnetic storm induced LSTIDs.
作者
魏乐惠
姜春华
赵正予
WEI LeHui;JIANG ChunHua;ZHAO ZhengYu(School of Electronic Information,Wuhan University,Wuhan 430072,China)
出处
《地球物理学进展》
CSCD
北大核心
2021年第2期508-515,共8页
Progress in Geophysics
基金
国家自然科学基金资助项目(41604133)资助.
关键词
垂测仪
FOF2
LSTIDs
磁暴
电离层暴
传播特性
Ionosonde
foF2
LSTIDs
Magnetic storm
Ionospheric storm
Propagation characteristics