Low-latitude ionospheric perturbations responding to zonal disturbance electric fields

The equatorial electric field plays an important role in low-latitude ionospheric plasma drifts and distributions at both quiet and disturbed time, which leads to complex ionospheric variability near the Equatorial Ionization Anomaly (EIA). In this study, ionospheric foF2 data from two low-latitude ionosondes and equatorial disturbance fields from an empirical model during fifty storms between 1978~1995 are picked in search of the nonlinear responses of low-latitude ionospheric perturbations to zonal disturbance electric fields. The results show that the responses exhibit remarkable differences versus season and location. This indicates that the low-latitude ionospheric variabilities caused by the disturbance electric field show deep relation to their quiet-time evolutions.