On the generation and evolution of aeroelectric structures in the surface layer

Ultralow frequency pulsations of electric field in the surface atmospheric layer were investigated under fair weather conditions. A new method of structural-temporal analysis has been applied to the study of spatiotemporal structures of the electric field described previously by [Anisimov ct al., 1994]. The method is based on exploration of the structural function by averaging the remote sensing data over respective temporal spans. This analysis allows quantitative estimations of spatial scales L similar or equal to 500 - 10(3) m and temporal scales not less than r = 10 min for the structural elements of the planetary boundary layer electricity; we call these recently examined elements "aeroelectric structures" (AES). Quasiperiodic sequences and high-amplitude solitary AES have been recognized. Three-dimensional structural-temporal patterns are presented which directly characterize the level of electric energy perturbations connected with AES formation during night-day evolution. A model of AES formation has been developed, taking into account the occurrence of convective cells with respective turbulent air and space charge density distributions that are transferred by the wind over the ground and cause the electric field fluctuations at the points of observation. Therefore formation of such submesoscale structures can be explained by the redistribution of space charge within the surface layer, with the structures of the smallest scales coupled to the turbulent mixing of the ions and aerosols. In addition to the advection and turbulent mixing of space charge, we also consider the cooperative electroaerodynamic effects which might occur in a system of bipolar ion and aerosol particles under the influence of a terrestrial electric field. We have proposed an advanced model treating the AES formation as the result of instability arising in such a system, taking into account the dependence of the effective ion-aerosol attachment coefficient on the external electric field strength.