Impact of magnetic storms on the lower ionosphere within the auroral zone

The results of the paper were based upon data on magnetic storms for a five-year period (2008-2012) such as vertical sounding data, magnetometer and riometer data from the Sodankylä station, and satellite data. The main efforts were directed to reveal the relationship between the level of absorption in the ionospheric D-region and magnetic field intensity in a disturbance bay. We detected thresholds in the level of absorption when ionospherically reflected signals were absent in the vertical sounding. Another task of the study was to reveal the relationship between maximum frequencies of E s layers and magnetic field intensity for the magnetic storm period. We established differences between the mentioned regularities for daytime and nighttime periods.