Abstract
It has been suggested that the atmospheric concentration of SO2 observed on Venus coincides with the equilibrium concentration over pyrite-magnetite assemblage (pyrite-magnetite buffer). If the atmospheric SO2 abundance is controlled by the chemical reaction at the planetary surface, we expect coupling between the atmospheric SO2 abundance and the surface temperature. Here, we propose that the pyrite-magnetite buffer combined with cloud albedo feedback controls the surface temperature on Venus. We show that this mechanism keeps the surface temperature in a rather narrow range around the presently observed value against large variations of solar luminosity and total atmospheric mass.
