Morphologies of Global Ionospheric Disturbances During Geomagnetic Disturbance Events of Different Type

Using the observational data from the global ionospheric stations, we analyzed the morphologies of global ionospheric F2‐layer (f0F2 and hmF2) disturbance during five different type geomagnetic disturbance events. The main results show that: for magnetic storms with delayed main phase, types S(C) and S(E), the middle–high latitude ionosphere demonstrates the evident positive phase disturbance first and the following negative phase disturbance is evidently delayed; the negative phase disturbance covers a wide region, even extends into low–latitudes, lasts a longer time, and recovers very slowly, in which the disturbance of type S(C) is more evident. For magnetic storm with no–delayed main phase, types S(A), S(B) and S(D), the ionospheric positive phase disturbance at high–latitudes lasts a shorter time, even does not appear at all, and the following middle–high latitude ionospheric negative phase disturbance starts, develops, and recovers rapidly. The intensity of magnetic storm main phase has certain effect on the intensity, development and periods of ionospheric negative phase disturbance. The ionospheric disturbances at high–latitudes have the evident local time effect in the recovery phase of storm with no delayed main phase. The local time effect is enhanced with the reduction of latitude, and evidently affects the ionosphere disturbances at middle–low latitudes. Generally, There are great differences for the ionospheric disturbances at different latitude regions, which reflect the interactions of the different physical processes.