The electric state of the middle-latitude convective atmospheric boundary layer (ABL) is investigated during a point in time when it is not disturbed by clouds, precipitation, mist, or industrial aero

The results of in situ ground-based observations of radon volumetric activity carried out at the Borok Geophysical Observatory of Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences (58°04′ N; 38°14′ E) are presented. Modeling the characteristic diurnal variation in the ion production rate in the undisturbed midlatitude lower atmosphere above land is carried out. The Lagrangian stochastic model of turbulent transport is developed in application to determining the vertical profiles of radon activity for 222Rn and 220Rn isotopes and their radioactive decay products. The results calculated by the Lagrangian stochastic model are matched with the analytical solution for the free atmosphere. Based on the model, the estimate is obtained for the rate of radon outflow from the convective boundary layer to the free clear sky atmosphere. The implications of temperature stratification of the atmosphere for the vertical distribution of the ion production rate at the different radon emission rate are explored.

The dynamics of the electric field in the planetary boundary layer (PBL) is thoroughly studied from in situ observations of the aeroelectric field and the height profiles of the wind-velocity components in the conditions of temperature inversion and incipient convection. It is established that the formation of a layer with temperature inversion is accompanied by a positive trend in the intensity of the aeroelectric field and by the generation of short-period aeroelectric pulsations. The transfer of a spatially nonuniform space charge and the formation of electrically active layers in PBL are studied by numerical modeling. The response of the electric field to the motion of the space charges simulating the coherent structures of electrogasdynamical turbulence is investigated for the vicinity of the observation point. The key parameters of the model distributions of the space charge are analyzed. The linear dimensions of the model structures range from 20 to 500 m, and the density of the transported charge varies from 0.1 to 1 nC/m³. The layer containing the model structures is located at a height of 60–300 m. It is shown that the spatial distribution and the transfer of the space charge form the dynamical component of the aeroelectric field in the surface layer. The short-period aeroelectric pulsations are induced by the transfer of the spatially heterogeneous space charge in PBL, while the positive trend is due to the accumulation of the space charge below the inversion layer. When the inversion was recorded by a sodar, the intensity of the field at the onset of the convection increased at a rate of 100 V/(m h) on average.