Modeling of high frequency radio wave absorption during solar events

The high frequency (HF) radio band is important for long distance communications, particularly in the polar region, where the ground infrastructure is limited. Space weather events adversely affect HF radio propagation. The influence of HF radio wave absorption induced by solar Ultra-Violet, X-ray flux and energetic particle precipitation on the ionogram structure is studied. The influence of the solar event observed on 11 April 2013 on the structure of vertical and oblique sounding ionograms in the Northern hemisphere of the Earth is considered. An adjustable model of the ionosphere developed for high frequency propagation problems was suggested and employed for this purpose. The simulation algorithm has been developed to describe a large variety of ionospheric conditions.