Observation of Travelling Ionospheric Disturbances over Morocco during the Godzilla Sand and Dust Storm of 15th to 26th June 2020 Using GNSS

Abstract

Using Vertical Total Electron Content (VTEC) data from four GNSS receiver stations: IFR1 (Ifrane Seismic), MELI (Melilla), TETN (Tetouan) and OUCA (Ouca) in Morocco, we investigate the Godzilla sand and dust storm (SDS) event of June 2020 as a source of energetics for generation of travelling ionospheric disturbances (TIDs). Godzilla SDS event began on 5th June 2020 in Algeria following a decrease in pressure and spread to other areas across the Sahara between 6th and 28th June 2020. It was tracked using the Sentinel-5P Satellite mission. Solar wind parameters: Horizontal component of interplanetary magnetic field (IMF Bz), Y-component of interplanetary electric field (IE-Ey), and solar wind speed (Vz) and geomagnetic indices: disturbance storm time (Dst) and planetary K (kp) indices were examined and showed very minimal geomagnetic influence during the period. The study showed that TEC exhibited wave-like structures having distinct troughs and peaks over IFR1-MELI-TETN and OUCA-IFR1-TETN arrays which were clear indicators of generation of TIDs. The arrays and de-trended TEC plots showed that the TIDs propagated poleward.  Neutral winds were seen to play a very important role in the propagation of the atmospheric gravity waves (AGWs) which are manifestations of TIDs.