Conduction current and extraneous electric current in the global electric circuit

Abstract

The role of the conduction current and extraneous electric current in the global electric circuit is considered. The current associated with the formation of thunderstorm and rain clouds charges the ionosphere positively relative to the Earth and creates a potential difference of ~250 kV between them. A global electric field directed toward the Earth arises. An electric current attributable to the electric conductivity of the atmosphere flows under the action of this field, which tends to discharge the Earth–ionosphere capacitor and is directed oppositely to the charging current. This electric current flows in the dry air of fair-weather regions. Under polluted, warm, and moist air conditions, the role of nonelectric forces in the generation of electricity between the ionosphere and Earth increases. The slow recombination of large charged particles produced by air ionization and electron attachment to heavy particles increases the density of charges, which are transferred under the action of gravity and pressure gradients. The predominant condensation of water vapors on negative charges followed by their coagulation lead to the mass separation of charges in the gravity field with the settling of negative charges and the rise of positive ones, i.e., to the appearance of an extraneous electric current (ionosphere charging current) directed oppositely to the conduction current. The atmospheric conditions above the tectonic fault during the preparation of earthquakes are shown to contribute to the generation of an extraneous electric current. The key factors that determine the intensity of the seismogenic electric current, its role in the generation of seismogenic electric fields in the ionosphere, and their thermospheric and ionospheric effects are discussed.