Analysis of the Magnetic Storm’s Influence on Ionospheric in September 2017

In order to study the effect of magnetic storm on the change of ionospheric TEC, this paper collects TEC global grid data from iGMAS and storm Dst index provided by SEPC during solar grade X93 large flares and magnetic storms on September 6 in 2017, and analyzes the correlation in different stages of magnetic storm between Dst index and TEC at different latitudes in the process of the magnetic storm. The results show that: 1)The large magnetic storm occurres 13 hours after the outbreak of the large flare, and the correlation coefficient between the ionospheric TEC lagging 1 hour and Dst index of the main phase during the magnetic storm is -09997, The ionospheric total electron content increase rapidly with the inten sification of magnetic starms, then decreases rapidly and tends to be stable during the recovery phase; 2) The change of TEC varies with the change of Dst index of magnetic storm, and the trends of the two changes are the same. The intensity of magnetic storm has a strong negative correlation with the change of TEC. The effect of magnetic storm on TEC of different latitudes tends to be consistent, and the degree of influence declines gradually from high latitude to low latitude; 3) The TEC changes in the high, medium and low latitudes after the magnetic storms are not synchronized. and the effect is taken in high, medium and low order. The delay of the influence on the different latitudes during the main phase of the magnetic storm is about 1 hour. The delay between Dst index and TEC delay gradually disappears during the recovery phase. With the storm reducing weak the ionospheric TEC change tends to be stable; 4) The abnormal changes of TEC occurre during the phase of magnetic storm recovery need to be further studied and analyzed.