Abstract: 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.