Enhanced Microwave Absorption in the Lower Atmosphere of Venus

Abstract

The enhanced microwave attenuation in the altitude range between 35 and 52 km is explained by the assumption of an atmospheric layer consisting of water vapor and water droplets. The mass density distributions were calculated from the attenuation coefficient, and refractivity was measured during the Mariner 5 occultation experiment; temperature and pressure were measured by the Venera probes. These independent measurements lead to a reasonable altitude distribution of the water droplets and the water vapor content. The results show good agreement with assumptions which have to be made to explain the brightness temperature of the planet Venus.