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The effects of one super and two intense storms on three European very low frequency (VLF) transmitter signals received at Algiers (Algeria) station, are presented. Two VLF transmitters (DHO and GQD) are located almost at the same mid‐latitude and third transmitter (NRK) at a high latitude, allowing us to study the latitudinal dependence of the storm effect on the VLF propagation. Two kind of ionospheric disturbances were considered: Direct effect of the field aligned currents (FACs) and the second concerning with the lightning‐induced electron precipitation (LEP) events. The FACs effect was clearly evident on the recorded signal amplitude during the daytime and nighttime. Our analysis of the short‐duration VLF perturbations due to LEP events showed that the ducted and non‐ducted LEPs are the majority of VLF perturbations and a small fraction of LEP events was associated with magnetospherically reflected waves on the high latitude transmitter path (NRK–Algiers). The coincident observation of LEP on the mid‐latitude transmitters (DHO and GQD) signals implies that the disturbance was large as much as the distance between the two transmitters (728 km). The modeling using Long‐Wave Propagation Capability (LWPC) code of LEP associated VLF perturbations considering Gaussian distribution of electron density enhancements, showed a decrease in the D‐region reference height from its usual value 87 km to 83.3 km for ducted LEP and 80.3 km for non‐ducted LEP event and that the non‐ducted event exhibited a wider disturbed region.

Abstract. In this work we show the result of the numerical simulation of the gravity waves (GWs) D region disturbance. Effectively, using the Glukhov-Pasko-Inan (GPI) model of the electron density in the D region we were figured out the response of the electron density due to gravity wave neutral atmosphere oscillation. As a consequence to the D region disturbance, the electron density sometimes increases when the neutral atmosphere density decreases and vice versa. This behavior was interpreted by the decreases or increases of ionization rate by chemical loss process. In a second simulation work, we used the Long Wave Propagation Capability (LWPC) code to simulate the Very Low Frequency (VLF) signal when the gravity wave disturbance crossed the VLF path. The effect of the disturbance is to decrease the VLF signal reflection height below the ambient altitude (87 km) when the electron density increases. On the other hand and when the electron density drops, the VLF reflection altitude increased higher than 87 km.