Ionospheric Irregularities Over Norilsk During the 27–28 May 2017 Geomagnetic Storm

We present the multi-instrumental study of ionospheric irregularities with different scales, which were observed over the Norilsk area, Russia, during a moderate-to-strong geomagnetic storm at May 27-28, 2017. Ionospheric electron density variations were observed by GNSS receivers, at the Swarm and DMSP satellites. From UHF radar data, we observed an intense auroral backscatter right after the initial phase of the geomagnetic storm. Concurrently, we have registered high rate of TEC fluctuations as deduced from the Norilsk GPS-receiver. Ionosonde data also exhibited a presence of the E-layer irregularities.