SPACE ELECTROMECHANICS. SPACE CRAFTS.NEAR-EARTH SPACE RESEARCH
The article presents the calculations of horizontal distribution of vertical electric current on the Earth surface caused by electrical interaction between a thunderstorm cloud and the Earth surface in steady conditions, when there are no lightning discharges. The electrical structure of a thunderstorm cloud is simulated using two Coulomb charges of opposite sign and equal magnitude placed one under the other (the negative charge is placed under the positive one). It is assumed that the ‘thunderstorm cloud - Earth’ system is in the conductive atmosphere, and the Earth surface is perfectly conducting. The obtained results show that on the Earth surface the vector of density of vertical electric current between a thunderstorm cloud and the Earth surface is directed upward in the area around the electrical axis of the cloud within a radius of ~7 km. Beyond this area the vertical electric current density vector is directed downward. The associated magnetic effect of vertical current on the Earth surface is maximal at a distance of ~3 km from the electrical axis of the cloud, where the magnetic perturbation magnitude is ~2 pT at absolute value of thunderstorm cloud charges being equal to 10 C.