太阳活动低年广州地区地磁扰动与电离层闪烁的统计特征分析

基于肇庆地磁台的地磁监测数据和广州气象卫星地面站建立的华南地区GPS电离层闪烁监测网的监测数据, 统计分析了2008年7月至2010年7月太阳活动低年期间广州地区地磁扰动与电离层闪烁的关系. 用肇庆台地磁水平分量H的变化量换算出肇庆地磁指数K, 以此来代表广州地区地磁扰动情况.分析结果表明, 磁暴/强地磁扰动对广州地区电离层闪烁的发生总体表现为抑制作用, 电离层闪烁主要发生在低K值期间, 而在K ≥ 4时电离层闪烁的发生呈下降趋势. 电离层闪烁发生率随季节和地磁活动的变化规律表现在, 春季的弱闪烁发生率、夜间中等以上闪烁发生率和夏季中等以上闪烁的发生率明显与地磁活动指数K相关, 即随$K$指数的增大而减小; 在秋季和冬季闪烁发生率与K指数变化无明显关系. 同时还综合分析了地磁与太阳活动的变化对电离层活动的影响, 广州地区闪烁主要发生在太阳活动较低的磁静日期间.

Statistical Analysis of Geomagnetic Disturbances and Ionospheric Scintillations Over Guangzhou Region During Solar Minimum

The correlations between geomagnetic disturbance and GPS ionospheric scintillations are studied here using geomagnetic monitoring data of Zhaoqing geomagnetic station and the ionospheric scintillations observed by GPS monitoring network of South China,which is established by Guangzhou meteorological satellite ground stations.With the use of geomagnetic K values converted from the variation of geomagnetic horizontal component H at Zhaoqing to represent geomagnetic disturbance over Guangzhou region,the relationships between the geomagnetic disturbance and amplitude scintillation index（S₄） over Guangzhou region during solar minimum are statistically analyzed. Analysis indicates that most storms/strong magnetic disturbances of the year did not trigger the scintillation occurrence,that the ionosphere scintillation occurrence is mainly confined to the periods of lower K values,and that the ionosphere scintillation occurrence declined for periods of higher K values（K≥4）.Occurrence rate of ionosphere scintillations is changed with seasons and the geomagnetic activities.The scintillations occurrence rate is obviously correlated with the variation of geomagnetic activity K index,i.e.,as the index K is raised,scintillation occurrence rate of above medium at night and weak in spring,as well as scintillations above medium in summer decreases. But there is no obvious relationship between occurrence rate of ionosphere scintillation and K values in autumn and winter.In addition,comprehensive analyses for the effects of geomagnetic and solar activity on ionosphere activity show that there are more ionosphere scintillations over Guangzhou region during geomagnetic quiet and low solar activity periods.