FORMATION OF THE ATMOSPHERIC ELECTRODE LAYER STRUCTURE

Abstract

The problem of the formation of the electric state in the lower layer of the atmosphere near
the Earth's surface is considered in the article. An electrodynamic model of a non-stationary turbulent-
convective surface layer is investigated in the approximation of the electrode effect. The
initial system consists of the ionization-recombination equations for aeroions and the Poisson
equation. Depending on the meteorological conditions in the atmosphere, the cases of classical
and turbulent electrode effects, as well as the approximation of strong turbulent mixing, are considered
separately. Turbulent and convective transport, the degree of air ionization, and the presence
of submicron aerosol particles in the air are factors that affect the space-time structure of the
electrode layer. Dimensionless parameters (similarity criteria) for electrodynamic equations are
revealed, which allow choosing the appropriate approximation for modeling the structure of the
electrode layer depending on atmospheric conditions. In an aerosol-free atmosphere, the time to
establish a stationary state in the electrode layer is about 5 minutes, for the classical layer (the
typical height is about 4-5 m), and in the turbulent layer-about 15 minutes. (the typical height is
about 10 m). In the case of strong turbulent mixing, the distribution scale of electrical quantities
increases to hundreds of meters. The ratio of the characteristic velocities of turbulent and convective
processes indicates the predominant physical mechanism of ion transport and the formation of
the electrode layer structure. An increase in the rate of convective transport directed downwards
leads to a weakening of the turbulent mixing mechanism, and when moving up, the opposite effect
occurs. The presence of a submicron aerosol in the atmosphere leads to the formation of heavy
ions, the mobility of which is much less than that of aeroions. Single-charged aerosol particles
with a concentration not exceeding the number of aeroions slightly change the spatiotemporal
characteristics of the electrode layer. While the presence of repeatedly charged aerosol particles
in the surface air increases the time of electrical relaxation and reduces the height of the electrode
layer. At sufficiently high concentrations of aerosol (more than the number of aeroions by an order
of magnitude or more), it is necessary to take into account its transport by turbulentconvective
flows, and the structure of the electrode layer is determined only by heavy ions.