A MODEL CALCULATION OF CYTHEREAN UPPER ATMOSPHERE

The dissociation and ionization of the Cytherean upper atmosphere are discussed, taking into account the photochemical processes, molecular diffusion, eddy diffusion, and ambipolar diffusion. The results of calculation show that, as the Schumann-Runge radiation can penetrate deeper into the atmosphere, the effect of lower atmosphere dynamics on the distribution of neutral atmospheric constituents is more appreciable on Venus than on Earth. By comparing the electron density profile in this calculation with that of the radio occultation measurement by Mariner 5, a deficiency of O atoms on Venus is concluded. The deficiency may be caused by the dynamical effect pointed out above. © 1969.