On the contribution of a convective generator into the global electric circuit

We derived the analytical expression for the ionospheric potential induced by convective currents in the planetary boundary layer (PBL). The convection is shown to amplify contributions of thunderstorm/shower cloud sources while the value of this amplification varies likely from 10 to 20 % depending on the square covered by intensive convection, on the mean PBL thickness, and the air column resistance. Diurnal changes of the convection area can result in regular changes in the ionospheric potential diurnal variation. These regular changes increase contributions of generators associated with the thunderstorm/shower cloudiness.