On Venus' cloud top chemistry, convective activity and topography: A perspective from HST

Sulfur monoxide dimer chemistry as a possible source of polysulfur in the upper atmosphere of Venus

“…However, as noted by ref. 25 , the lifetime of the UV absorber is much longer than that of SO 2 , and as a result, the ratio of their abundances is strongly affected by transient atmospheric dynamics, in particular convective activity. Upward transport in the ascending branch of the Hadley Cell could bring absorber upward from where it is formed in the lower half of the upper cloud deck.…”

Venus, an Astrobiology Target

“…Weaker absorption occurs over a wider range of wavelengths beyond 500 nm. SO2 and SO gas absorption is responsible for the distinct absorption bands observable below 330 nm [58]; and an underlying continuum absorption from an unknown source is also anticipated below 300 nm [59,60]. Although Figure 1 shows that only weak absorptions occur longward of 400 nm-it is important to know if chemical species producing the underlying continuum absorption shortward of 300 nm also contribute weakly to absorption properties evident longward of 400 nm or even combine with the CO2 and H2O absorptions identified at visible and NIR wavelengths.…”

Laboratory Studies in Support of Venus Exploration: Surface and Near-Surface

“…Because the nature and origin of the Absorber are not known, its relationship to the abundance and distribution of photochemical products and their diurnal and/or climatic chemical cycles is also unknown (8)(9)(10). Its cloud-top abundance is strongly affected by subsolar mixing and zonal transport rather than short-time scale chemical reaction (8,11), but there may be linkages to SO2 abundance at the cloud top (10). A key unknown about the UV Absorber is its distribution with height ; its elevation distribution is inferred from spectrography during a single descent spacecraft descent at a single local time (12).…”