南极长城站周边地区电离层TEC变化特性

Variations of ionospheric TEC surrounding Great Wall Station,Antarctica

电离层总电子含量(Total Electron Content,TEC)是描述电离层电波环境特性的重要参量.利用GPS观测数据分析讨论了南极长城站周边电离层TEC环境的规则和扰动变化,结果表明:电离层TEC具有明显的威德尔海异常特征,夏季夜侧要高于日侧,其极大值出现在地方时5h前后,而冬季和分季则以地方时11h前后为极大;电离层TEC负相暴在地方时12h前后发生率极低,表现出所谓的"禁时效应";电离层TEC暴事件发生率随太阳活动性的增强而升高,且其在夏季为极小,两分季为极大;高达94.8%的电离层TEC暴事件发生伴随有较强的极光电集流AE(Auroral Electrojet)指数扰动,这预示着该地区电离层TEC暴变事件与极光亚暴活动有着很强的相关性.

Total electron content（TEC）is an important characteristic parameter for ionospheric radiowave environment.The variations of ionospheric TEC are investigated by using GPS data observed from the surrounding of the Great Wall Station,Antarctica.Results show that the Weddell Sea Anomaly（WSA）can be observed which the TEC value is higher on nightside than dayside in summer.And the maximum values of TEC appears at 5hLT in summer and at 11 hLT in winter and equinoxes.The silent effect of negative storm is revealed for its rare occurrence around 12 hLT.The occurring rate of TEC storm becomes higher with the rise of solar activities,and it is minimum in summer and is maximum in equinoxes.Up to 94.8% of TEC storm events are accompany with the intense disturbances of AE index,and it suggests the relativity is very strong between the auroral substorm and the TEC storm.