Determining the position of the of thunder infrasound source using a large aperture micro barometer array

Large aperture array of absolute micro‑barometers located in Western Czechia was used to register distinct infrasound pulses generated by thunderstorm activity. Only cases with a sufficient signal-to-noise ratio on all four micro‑barometers were selected for further processing. Using data from the European lightning detection network and electric field monitor, a corresponding flash was assigned to each set of signals. The position of the infrasound source was calculated from the time delay of signal arrival, assuming propagation of spherical waves from the source. The calculation includes changes in sound speed as a function of temperature variation with altitude. Wind speed value and its variance is also taken into account to estimate the uncertainties. The calculated vertical positions of the infrasound sources are located at the altitudes between 3‑6 km. The horizontal position for most of the selected cases corresponds to the horizontal position of the flash specified by lightning detection network. The recorded infrasound signals followed only intracloud (IC) or mixed (multiple IC+CG) lightning strokes. Thus, the sources of the analyzed infrasound events are most likely IC discharges.