Near-IR oxygen nightglow observed by VIRTIS in the Venus upper atmosphere - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of Geophysical Research. Planets Année : 2009

Near-IR oxygen nightglow observed by VIRTIS in the Venus upper atmosphere

Résumé

We present observations of both the (0-0) and (0-1) bands at 1.27 and 1.58 mum of the O2(a1Deltag - X3Sigmag -) nightglow made with the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) instrument aboard Venus Express. The observations were conducted in both nadir and limb viewing modes, the latter constituting the first systematic investigation into the vertical distribution of the volume emission rate of the infrared oxygen nightglow in Venus' upper atmosphere. Limb measurements from 42 orbits covering the latitude range 7°S to 77°N are analyzed. The peak altitude of the volume emission rate occurs typically between 95 and 100 km, with a mean of 97.4 ± 2.5 km. The vertical profile is broader near the equator, with a full width at half maximum of 11 km, a factor 2 larger than at middle latitudes. A double peak is frequently observed, with the lower and upper peaks occurring near 96-98 km and 103-105 km, respectively. On average, the nightglow appears brightest in the vicinity of the antisolar point. This conclusion is consistent with past ground-based observations and nadir measurements by VIRTIS. We mapped the global mean O2 nightglow intensity from VIRTIS data collected during 880 orbits. Patchy features of the nightglow intensity observed in nadir view are correlated with the thermal brightness at 4.23-4.28 mum. The observed positive correlation is consistent with downwelling (upwelling) of oxygen atoms accompanying compressional heating (expansion cooling) or with modulation by gravity waves. Finally, from simultaneous measurements of the 1.27 and 1.58 mum bands, we have estimated the ratio of the transition probabilities A00/A01 to be 63 ± 8.
Fichier principal
Vignette du fichier
Journal of Geophysical Research Planets - 2009 - Piccioni - Near%u2010IR oxygen nightglow observed by VIRTIS in the Venus upper.pdf (1.1 Mo) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

hal-03648633 , version 1 (21-04-2022)

Licence

Copyright (Tous droits réservés)

Identifiants

Citer

Giuseppe Piccioni, Ludmilla Zasova, Alessandra Migliorini, Pierre Drossart, Alexey V. Shakun, et al.. Near-IR oxygen nightglow observed by VIRTIS in the Venus upper atmosphere. Journal of Geophysical Research. Planets, 2009, 114, ⟨10.1029/2008JE003133⟩. ⟨hal-03648633⟩
64 Consultations
32 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More