Aerosol-induced correlation between visibility and atmospheric electricity

Atmospheric aerosol acts both to reduce the background concentration of natural cluster ions, and to attenuate optical propagation. Hence, the presence of aerosol has two consequences, the reduction of the airʹs electrical conductivity and the visual range. Ion-aerosol theory and Koschmiederʹs visibility theory are combined here to derive the associated non-linear variation of the atmospheric electric potential gradient with visual range. A substantial sensitivity is found under poor visual range conditions, but, for good visual range conditions the sensitivity diminishes and little influence of local aerosol on the fair weather potential gradient occurs. This allows visual range measurements, made simply and routinely at many meteorological sites, to provide inference about the local airʹs electrical properties.