Sulfur dioxide in the Venus atmosphere: I. Vertical distribution and variability

Authors

Contributors

Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgi...; Moscow Institute of Physics and Technology Moscow (MIPT); Space Research Institute of the Russian Academy of Sciences (IKI); Russian Academy of Sciences Moscow (RAS); Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA); Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris; Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS); Laboratory for Atmospheric and Space Physics Boulder (LASP); University of Colorado Boulder; Department of Space Studies Boulder; Southwest Research Institute Boulder (SwRI); PLANETO - LATMOS; Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS); Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS); Space Science and Engineering Center Madison (SSEC); University of Wisconsin-Madison; Fonds National de la Recherche Scientifique Bruxelles (FNRS); Fenner School of Environment and Society; Australian National University (ANU); Space Science Institute Boulder (SSI); Department of Atmospheric, Oceanic, and Space Sciences Ann Arbor (AOSS); University of Michigan Ann Arbor; University of Michigan System-University of Michigan System; Space Telescope Science Institute (STSci); Clarendon Laboratory Oxford; University of Oxford + 25

Published in

ISSN: 0019-1035

Publisher

HAL CCSD; Elsevier

Abstract

International audience ; Recent observations of sulfur containing species (SO 2 , SO, OCS, and H 2 SO 4 ) in Venus’ mesosphere have generated controversy and great interest in the scientific community. These observations revealed unexpected spatial patterns and spatial/temporal variability that have not been satisfactorily explained by models. Sulfur oxide chemistry on Venus is closely linked to the global-scale cloud and haze layers, which are composed primarily of concentrated sulfuric acid. Sulfur oxide observations provide therefore important insight into the on-going chemical evolution of Venus’ atmosphere, atmospheric dynamics, and possible volcanism.This paper is the first of a series of two investigating the SO 2 and SO variability in the Venus atmosphere. This first part of the study will focus on the vertical distribution of SO 2 , considering mostly observations performed by instruments and techniques providing accurate vertical information. This comprises instruments in space (SPICAV/SOIR suite on board Venus Express) and Earth-based instruments (JCMT). The most noticeable feature of the vertical profile of the SO 2 abundance in the Venus atmosphere is the presence of an inversion layer located at about 70–75 km, with VMRs increasing above. The observations presented in this compilation indicate that at least one other significant sulfur reservoir (in addition to SO 2 and SO) must be present throughout the 70–100 km altitude region to explain the inversion in the SO 2 vertical profile. No photochemical model has an explanation for this behaviour. GCM modelling indicates that dynamics may play an important role in generating an inflection point at 75 km altitude but does not provide a definitive explanation of the source of the inflection at all local times or latitudesThe current study has been carried out within the frame of the International Space Science Institute (ISSI) International Team entitled ‘SO 2 variability in the Venus atmosphere’.