2000年7月和2003年10月大磁暴期间东亚地区中低纬电离层的GPS TEC的响应研究

Analysis of the Intense Magneticstorm of July, 2000 and of October, 2003 Using the Technique for Nowcasting of GPS TEC Data

利用武汉电离层观象台研制的GPSTEC的现报方法及现报系统,对东亚地区GPS台网的观测数据进行处理分析,特别对2000年7月14-18日和2003年10月28日至11月1日两次特大磁暴期间的数据进行了对比考察.文中分析了两次磁暴间的电离层响应,得到对应不同磁暴时段电离层TEC的不同变化情况,着重揭示了TEC赤道异常峰的压缩和移动以及赤道异常随时间的压缩-反弹-恢复的过程,并结合高纬电离层的部分响应机制进行了说明.结果显示,两次磁暴期的电离层响应表现出了各自不同的特点,从而反映出因季节变化引起的高纬电离层暴时能量注入的不同而造成的全球性电离层扰动的不同形态.由此看出,磁暴期间电离层TEC的变化直接与太阳扰动发生的时间及其对高纬电离层的耦合有关.若短时期内连续发生多次磁暴,则电离层反应更加复杂,不能简单地当做单一磁暴叠加处理.

With a worldwide GPS network, the data of the July 14-18, 2000 geomagnetic storm and the October 28-November 1, 2003 storm is studied and compared using the technique for nowcasting of GPS TEC developed by the ionospheric station of Wuhan ionosphere observatory. In this paper, the ionospheric responses and the TEC variation during these two storms are discussed, especially the reducing and moving of the perturbation structure around the geomagnetic equator during storms and the ionospheric responses of high latitude part are analyzed. The results show that the ionospheric responses during these two storms are different and this difference is primarily caused by the seasonal difference of the magnetospheric energy deposition into the polar upper atmosphere. It is shown that the TEC variation is associated with the local time the solar perturbing occurred and the coupling of the ionospheric particles of high latitude with the solar particle. If there are several magnetic storms occurring in series, the ionospheric responses are more complex and disordered than the state that only one storm occur in a few days.