Study of Power Variations of Radio Occultation Signals in the Earth's High-Latitude Ionosphere During the Magnetic Storm in March 2015

The results of about 50 sessions of radio occultation sounding of the Earth's high-latitude (>60° N) ionosphere, conducted on March 17–18, 2015 for two ranges L1 (~19.0 cm) and L2 (~24.4 cm) of decimeter (DM) waves, have been analyzed. Coronal mass ejections that reached the Earth's magnetosphere during the specified time period provoked a strong magnetic storm of class ( = - 4), in which the maximum values of the -index were equal to 8. The storm caused significant fluctuations in the characteristics of DM radio waves along the sounding paths. The most noticeable variations in the radio wave power were observed in the -region of the Earth's lower ionosphere at altitudes below ~110 km. Here, the disturbances in the power of DM signals arising due to ionospheric irregularities with vertical dimensions 2 km) in power and refractive attenuation of radio waves which indicates the decisive contribution of layered irregularities to the observed variations.