An Estimate of the Minimum Distance to Lightning Events Associated with Cosmic Ray Enhancements during Thunderstorms

The experiment made with the Baksan air shower array discovered two types of pre-lightning enhancements of the soft component of cosmic rays. We present the preliminary results of an experiment in which the distance to lightning events associated with such enhancements is estimated acoustically using a simple microphone system. During observations in the autumn of 2002, we have succeeded in finding some events, for which it was possible to measure minimum distances to lightning channels. These distances turned out to be fairly large.