Variations in Venus' Cloud Top SO2 and SO Gas Density with Latitude and Time of Day
Abstract
Venus' upper atmospheric H2SO4 clouds are formed from SO2 gas via the sulfur-oxidation cycle, beginning with SO2 photolysis; followed by the formation of SO3 via photochemical SO2 oxidation, which then reacts with H2O forming H2SO4. Thus, photochemical processing of SO2 is intimately linked to the global-scale cloud and haze layers, which are composed primarily of concentrated sulfuric acid. At the same time, detailed thermochemical modeling of Venus' key atmospheric species suggests that the sulfur dioxide in Venus' atmosphere most likely originates from volcanic outgassing [1], though volcanic activity has yet to be directly observed. The exchange of SO2 from below the cloud deck to above the clouds is not fully understood, but undoubtedly involves convection transport [2, 3] and may also include direct volcanic injection of the SO2 gas [4]. Consequently, observations of sulfur oxides (SO2, SO, OCS, and H2SO4) in Venus' mesosphere are of great interest because they provide important insight into the ongoing chemical evolution of Venus' atmosphere, atmospheric dynamics, and possible volcanism.
- Publication:
-
European Planetary Science Congress
- Pub Date:
- September 2013
- Bibcode:
- 2013EPSC....8..842J