Investigation of the effects of geomagnetic storms on ionospheric irregularities using the combination of ground-based GNSS and SWARM satellites

Geomagnetic storms are one of the main causes of ionospheric perturbations in different sizes, depending on their intensity, which could disturb radio signals passing through this medium. On September 6-12, 2017, the sudden storm commencement (SSC) was the most massive geomagnetic storm of the year due to the X9 solar flare caused by a coronal mass ejection (CME). IMF-Bz and Dst values increased when the first SSC occurred at 23:43 on September 6. The second SSC has a more vigorous intensity at 23:00 on September 7 caused a dramatic increase in other geophysical parameters such as Kp and AE. During the second SSC Kp index reached 8, and AE reached 2500 nT. In this research, ionospheric irregularities over OLO3 station (-2.75E,35.87N,1483.00H) located at Arusha in Tanzania were analyzed using ground-based GNSS data and in situ measurements SWARM satellites. This procedure was applied to VTEC, signal to noise ratio (S4), and Rate of TEC Index (ROTI) values obtained from ground-based GNSS (GB-GNSS) and SWARM A & C to identify ionospheric perturbations during the geomagnetic storm. Furthermore, Langmuir plasma probes of SWARM satellites were implemented to recognize the rate of electron density (RODI). The results show that GB-GNSS and Swarm satellites geophysical ionospheric parameters increased during September 6-12, indicating the effect of the geomagnetic storm on the increase of ionospheric perturbations. This work shows the potential of using space‐based in situ measurement to detect ionospheric irregularities caused by the geomagnetic storm for areas where ionospheric observations are hardly possible such as oceans and deserts.