Analyzing solar, cosmic, and geophysical events in September 2017 using SHIСRA SB RAS complex observations

We report the results of monitoring of cosmic rays and geomagnetic field along 210 magnetic meridians in Yakutia in the first half of September 2017. The energy spectrum of solar cosmic rays during Ground Level Enhancement in September 10, 2017 is estimated as J =3027 E -1.99exp(- E /729 MeV). We present the results of the forecast and complex analysis of the magnetic storm on September 7-9, 2017 with Dst =-124 nT. The forecast lead time is about one day. We examine how the storm affected the electric potential and VLF signal propagation from RSDN-20 radio navigation stations. Irregular Pi3-Pi1 pulsations occurred during the September 8, 2017 magnetic storm from 12 to 20 UT. The pulsations were accompanied by variations in electrotelluric potentials and geomagnetic fields with the correlation coefficient between them ρ( E, H )=0.5÷0.9. The effects of the magnetic storm manifested themselves as an increase in the attenuation and a decrease in the phase delay of VLF radio signals.