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Venus OH nightglow distribution based on VIRTIS limb observations from Venus Express
Author(s) -
Soret L.,
Gérard J.C.,
Piccioni G.,
Drossart P.
Publication year - 2010
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2010gl042377
Subject(s) - airglow , venus , intensity (physics) , brightness , altitude (triangle) , physics , atmosphere (unit) , atmospheric sciences , flux (metallurgy) , excited state , astrophysics , atomic physics , astronomy , astrobiology , chemistry , optics , geometry , meteorology , mathematics , organic chemistry
The full set of VIRTIS‐M limb observations of the OH Venus nightglow has been analyzed to determine its characteristics. Based on 3328 limb profiles, we find that the mean peak intensity along the line of sight of the OH(Δv = 1 sequence) is 0.35 −0.21 +0.53 MR and is located at 96.4 ± 5 km. The emission is highly variable and no dependence of the airglow layer altitude versus the antisolar angle is observed. The peak brightness appears to decrease away from the antisolar point even if the variability at a given location is very strong. Some correlation between the intensity of the OH and the O 2 (a 1 Δ) emissions is also observed, presumably because atomic oxygen is a common precursor to the formation of O 2 (a 1 Δ) and O 3 , whose reaction with H produces excited OH. Comparing our results with predictions from a photochemical model, a constant H flux does not match the simultaneous OH and O 2 airglow observations.