Radio Wave Characteristics Distorted During Geospace Storm: Results of Multi-Frequency Multiple Path Oblique Sounding of Ionosphere

We have made measurements of HF radio waves at the Harbin Engineering University, the People's Republic of China, during the geospace storm of August 30-September 2, 2019. Further, we have performed a general analysis of space weather, and afterwards the data and disturbances in the ionosphere have been analysed in order to determine the effect that the ionospheric storm had on the parameters of radio waves. The main results of this analysis could be summarised as follows. The magnetic storm power and energy have been calculated to be 9 × 10
⁹
W and 1.5 ×10
¹⁵
J, i.e., the storm was moderate. The geospace storm included a strong to moderate negative ionospheric storm. During August 31, 2019 and September 1, 2019, the
$F$
region of the ionosphere showed a reduction in the electron density by a factor of 1.4 to 2.4 in comparison with the electron densities observed on the reference day. The geospace storm also caused notable disturbances in the midlatitude
$E$
region of the ionosphere, and in the sporadic E
s
layer. During the ionospheric storm, the heights of reflection could undergo a drastic rise from ~150 km to ~300-310 km. The geospace storm launched atmospheric gravity waves that modulated the electron density in the ionosphere.