Presentation #204.05 in the session Venus.
Ever since the detection of the enigmatic ultraviolet absorption in the upper atmosphere of Venus, questions have been raised about the identity of the unknown UV-visible absorber(s) and how it is formed on Venus. Although SO dimers are not likely to be the major UV absorber(s) in Venus’ upper atmosphere, they are important intermediaries in the formation of more complex S species such as Sn (n = 1 to 7) that might be. Polysulfur aerosol, Sx, which is formed by the nucleation of Sn (n = 1 to 7), has long been suspected as the source of the unknown UV absorber(s), but never confirmed (Pinto et al., 2021). In this work, we estimate the mixing ratio of polysulfur aerosol in the upper atmosphere. We inserted the profile of Sx calculated by our photochemical Model, KINETICS, into the Spectral Mapping Atmospheric Radiative Transfer model (SMART), and we find reasonably good agreement between the simulated UV spectrum of Venus and the observed spectral bond albedo of Venus. This result provides useful constraints for understanding the chemistry of the upper atmosphere of Venus and for unraveling the identity(ies) of the unknown UV-visible absorber(s).