The upper cloud layer of Venus and the supracloud haze (Review)

Some questions on the nature of the contrast features observed in ultraviolet radiation in the cloud layer of Venus are discussed: their structure and dynamics; stratification of the supracloud haze in the region of the morning and evening terminators; and the properties of the upper layer of clouds from radiometric data. The results of photometric, polarimetric, television, and radiometric experiments on the Venera-9, Venera-14, Mariner 10, and Pioneer-Venus spacecraft are used in this review. In 1975 a set of experiments directed toward investigations of the upper cloud layer of Venus was placed on Venera-9 and Venera-10 spacecraft.