2007 Volume 22 Issue 2 Pages 95-100
The sulfuric acid cloud of Venus is a highly-variable and complicated system driven by photochemistry and atmospheric dynamics. The upper part of the cloud layer is generally thought of as photochemical haze, while the lower part is formed by the condensation of sulfuric acid vapor supplied by dynamical motions from the reservoir below. The elucidation of this system is crucial for understanding the energy balance and the chemical cycle of the Venusian atmosphere. In spite of many previous observations and theoretical studies, however, many fundamental questions raised so far still remain unsolved. Various observations with new techniques are now being conducted to explore this complicated system.