GPS Observations of Ionospheric Effects of the Major Storm of Nov. 7–10, 2004

Abstract

AbstractThe TEC and amplitude scintillation measurements have been carried out at Wuhan (114.36°E, 30.53°N, magnetic latitude 19.4°) since 2003 using a GPS ionospheric total electron content (TEC) and scintillation monitor to investigate the ionospheric irregularities and TEC disturbances at the region of the equatorial anomaly. In this paper ionospheric effects of the magnetic storm of November, 2004 are analyzed by using GPS observations. Results of data analysis show that the ionospheric storm during this magnetic storm mainly exhibits the long duration positive storm phase around Wuhan, and the positive deviations of TEC occur during two main phases of the storm on November 8 and 10 with the largest deviation of 50 TECU. Another primary effect of the storm on the ionosphere is the remarkably enhanced activity and intensity of amplitude scintillations during the later main phase. The maximum value of the S4 index exceeded 1.0. There occurred the plasma bubbles and TEC fluctuations initiated from the equatorial region at the same time when strong amplitude scintillations occurred. A comparison between amplitude scintillations and TEC fluctuations was made. The statistic analysis shows there is a remarkable positive correlation between standard deviation of the change rate of TEC, the ROTI index, and the S4 index with correlation coefficient of 0.97.