• DOI:10.1038/nature06140
• Corpus ID: 4344611

A dynamic upper atmosphere of Venus as revealed by VIRTIS on Venus Express

@article{Drossart2007ADU,
  title={A dynamic upper atmosphere of Venus as revealed by VIRTIS on Venus Express},
  author={Pierre Drossart and Giuseppe Piccioni and J.‐C. G{\'e}rard and Miguel Angel Lopez‐Valverde and Agust{\'i}n S{\'a}nchez‐Lavega and L. V. Zasova and Ricardo Hueso and Fredric W. Taylor and Bruno B{\'e}zard and Alberto Adriani and Francesco Angrilli and Gabriele Arnold and Kevin H. Baines and Giancarlo Bellucci and Johannes Benkhoff and J. P. Bibring and Armando Blanco and Maria I. Blecka and Robert W. Carlson and Angioletta Coradini and Andrea Maria di Lellis and Thérèse Encrenaz and St{\'e}phane Erard and Sergio Fonti and Vittorio Formisano and Thierry Fouchet and R. Garc{\'i}a and R. Haus and J. Helbert and Nikolay I. Ignatiev and P.G.J. Irwin and Y. Langevin and S{\'e}bastien Lebonnois and David Luz and Lucia Marinangeli and Vincenzo Orofino and Alexander V. Rodin and Maarten C. Roos-Serote and Bortolino Saggin and Daphne M. Stam and D. V. Titov and Guido Visconti and Massimo Zambelli and Constantine C. C. Tsang},
  journal={Nature},
  year={2007},
  volume={450},
  pages={641-645}
}

• P. Drossart, G. Piccioni, +41 authors C. Tsang
• Published 29 November 2007
• Physics, Environmental Science
• Nature

The upper atmosphere of a planet is a transition region in which energy is transferred between the deeper atmosphere and outer space. Molecular emissions from the upper atmosphere (90–120 km altitude) of Venus can be used to investigate the energetics and to trace the circulation of this hitherto little-studied region. Previous spacecraft and ground-based observations of infrared emission from CO2, O2 and NO have established that photochemical and dynamic activity controls the structure of the upper atmosphere of Venus. These data, however, have left unresolved the precise altitude of the emission owing to a lack of data and of an adequate observing geometry. Here we report measurements of day-side CO2 non-local thermodynamic equilibrium emission at 4.3 µm, extending from 90 to 120 km altitude, and of night-side O2 emission extending from 95 to 100 km. The CO2 emission peak occurs at ∼115 km and varies with solar zenith angle over a range of ∼10 km. This confirms previous modelling, and permits the beginning of a systematic study of the variability of the emission. The O2 peak emission happens at 96 km ± 1 km, which is consistent with three-body recombination of oxygen atoms transported from the day side by a global thermospheric sub-solar to anti-solar circulation, as previously predicted.