Influence of the solar flares in March 2012 on the conductivity profile of the high-latitude lower ionosphere

The ionospheric D-layer affects the electromagnetic waves propagated in the Earth - ionosphere waveguide. It is known that the propagation velocity of atmospherics - electromagnetic pulses from lightning discharge depends on the conductivity profile of the lower ionosphere. In this paper the authors have considered the influence of solar flares in March 2012 on the propagation velocity of atmospherics and thus the state of the high-latitude lower ionosphere. The possibility to estimate the conductivity profiles of the daytime ionosphere under disturbed and undisturbed geomagnetic conditions using the measurements of the propagation velocity of atmospherics along the high-latitude path has been demonstrated