Characteristics of Low-Latitude Ionosphere Activity and Deterioration of TEC Model during the 7–9 September 2017 Magnetic Storm

Under the influence of space weather, abnormal disturbances in ionosphere will distort model seriously and affect global navigation satellite system negatively. This study analyzes ionospheric activity characteristics performance low latitude during a strong geomagnetic storm from 7 to 9 September 2017. The research goals are determine behavior refine latitude. In experiment, vertical total electron content (VTEC) peak value at latitudes caused by this was significantly higher than that on quiet day, VTEC increased approximately 75%. main phase storm, degree variation with longitude is day. trend northern hemisphere more severe southern hemisphere. region where decreases longitude, same latitudes, phenomenon not affected disturbance recovery phase. During daily minimum different basically same, 5 TECU, indicating nighttime weakly storms. Geomagnetic storms lead anomalous features “Fountain effect” latitudes. addition, event accuracy spherical harmonics (SH), polynomial, ICE models decrease 7.12%, 27.87%, 48.56%, respectively, serious distortion, which negative values fitted polynomial model.