Barium cloud growth in a highly conducting medium

An equation of motion is obtained for the spatial and temporal growth of an artificial barium cloud in the ionosphere. The method involves the expansion of the ion and electron fluid equations to first order in λ, where λ (assumed small) denotes the ratio of the integrated Pedersen conductivity in the cloud to that in the background ionosphere. The resulting diffusion equation for the ion density is solved by numerical means. The dielectric screening represented by the first term in λ produces significant distortions in an otherwise ellipsoidally shaped cloud. The forward moving part of the cloud thins and is indented, whereas the backside steepens. The steepening time varies inversely with λ and EA, the ambient electric-field strength.