Thunderstorm cloud cellular automaton model

We consider the thunderstorm (TC) activity on the basis of a cellular automaton model on tree-dimensional lattice. Each site of the lattice is related to a time-dependent scalar that characterises potential of the point. In our model, the potential differences between the neighboring sites are growing due to the instability effects. The potential difference growth is limited by some critical value. As soon as this critical value is reached for any two neighboring sites on the lattice, breakdown between the sites takes place and the lattice bond between the sites becomes a conductor. We assume that such a fine scale spark discharge can initiate breakdowns of the neighboring lattice bonds (“infect” the neighbors) if the potential difference between the cells exceeds some activation level, which is below the critical one. Interaction of neighboring cells leads to formation of dynamical chains of microdischarges, which reveal percolation-like behavior in a broad range of TC parameters. We show that fractal dynamics of electrical microdischarges in a thundercloud can serve as the basis for explanation of main features of a lightning flash in its preliminary stage.