Cloud Charging in the Atmosphere of Venus

The accumulation of charges on cloud particles in the atmosphere of Venus is investigated. Three cloud layers between 45 and 70 km exist in the atmosphere of Venus. The cloud particles are charged by the attachment of ions and electrons. Ion to particle and electron to particle attachment coefficients are calculated. The charge balance equations include ion-ion recombination, ion-electron recombination, electron attachment to neutrals, electron detachment from negative ions, and attachment of ions and electron to particles. It is found that the ion concentrations are reduced by a maximum of a factor of five by the attachment to the particles while the earlier studies showed a maximum reduction of about an order of magnitude due to the differences in the surface area of the particles used. A similar result is observed in the calculation of conductivity. Both monodisperse and polydisperse distribution of particles are considered. The conductivity was reduced by a factor of three when using the monodisperse distribution of particles, the maximum reduction observed was a factor of two when using the polydisperse distribution. This result implies that the monodisperse particle distribution overestimates the effect of particles on the atmospheric conductivity. The ratio of negative to positive charges is found to be very large in the middle and upper cloud layers.