LAUSR

We compare simulations of muon traversal in the atmosphere and observation of the muon flux made on the Earth's surface to reveal the relation of the muon flux changes to the charge structure of the lower part of the thundercloud. The results show that the changes in the muon flux during large thunderstorm ground enhancements (TGEs) reveal the charge configurations of the cloud, namely a large negative electric field in the lower part of the cloud and an inverted dipole. Cosmic ray muons do not originate particle avalanches in the thunderclouds, like electrons. However, in the thundercloud, the positive and negative muons are decelerated or accelerated according to the sign of the intracloud electric field. Due to the charge asymmetry of the muon flux (excess of positive muons over negative), the total number of muons and muon charge ratio also changes.