Atmospheric infrasound observed during intense convective storms on 9-10 July 2011

Atmospheric infrasound of frequencies 0.1-4 Hz observed in Central Europe during convective storms on 9-10 July 2011 from 21:00 to 02:57 UT was analysed. Azimuth of signal arrival followed positions of the convective storms passing over the region of measurements from south-west to north-east. Significant variations in azimuths of signal arrival (up to 105°) occurred periodically between 21:30 and 23:00 UT, at the time of maximum development of convective storms. Sprites (discharges in the mesosphere) seem to be potential sources of these infrasound signals. Stable infrasound arrivals were observed between 02:00 and 02:57 UT from direction where abating convective storms were located.