Unexpected increase of the deuterium to hydrogen ratio in the Venus mesosphere.

ABSTRACT: This study analyzes H₂O and HDO vertical profiles in the Venus mesosphere using Venus Express/Solar Occultation in the InfraRed data. The findings show increasing H₂O and HDO volume mixing ratios with altitude, with the D/H ratio rising significantly from 0.025 at ~70 km to 0.24 at ~108 km. This indicates an increase from 162 to 1,519 times the Earth's ratio within 40 km. The study explores two hypotheses for these results: isotopic fractionation from photolysis of H₂O over HDO or from phase change processes. The latter, involving condensation and evaporation of sulfuric acid aerosols, as suggested by previous authors [X. Zhang et al., Nat. Geosci. 3, 834-837 (2010)], aligns more closely with the rapid changes observed. Vertical transport comp

SUBMITTER: Mahieux A 

PROVIDER: S-EPMC11348243 | biostudies-literature | 2024 Aug

REPOSITORIES: biostudies-literature