| Literature DB >> 18046396 |
P Drossart1, G Piccioni, J C Gérard, M A Lopez-Valverde, A Sanchez-Lavega, L Zasova, R Hueso, F W Taylor, B Bézard, A Adriani, F Angrilli, G Arnold, K H Baines, G Bellucci, J Benkhoff, J P Bibring, A Blanco, M I Blecka, R W Carlson, A Coradini, A Di Lellis, T Encrenaz, S Erard, S Fonti, V Formisano, T Fouchet, R Garcia, R Haus, J Helbert, N I Ignatiev, P Irwin, Y Langevin, S Lebonnois, D Luz, L Marinangeli, V Orofino, A V Rodin, M C Roos-Serote, B Saggin, D M Stam, D Titov, G Visconti, M Zambelli, C Tsang, Eleonora Ammannito, Alessandra Barbis, Rainer Berlin, Carlo Bettanini, Angelo Boccaccini, Guillaume Bonnello, Marc Bouyé, Fabrizio Capaccioni, Alejandro Cardesin, Francesco Carraro, Giovanni Cherubini, Massimo Cosi, Michele Dami, Maurizio De Nino, Davide Del Vento, Marco Di Giampietro, Alessandro Donati, Olivier Dupuis, Sylvie Espinasse, Anna Fabbri, Agnès Fave, Iacopo Ficai Veltroni, Gianrico Filacchione, Katia Garceran, Yamina Ghomchi, Maurizio Giustizi, Brigitte Gondet, Yann Hello, Florence Henry, Stefan Hofer, Gerard Huntzinger, Juergen Kachlicki, René Knoll, Driss Kouach, Alessandro Mazzoni, Riccardo Melchiorri, Giuseppe Mondello, Francesco Monti, Christian Neumann, Fabrizio Nuccilli, Jérôme Parisot, Claudio Pasqui, Stefano Perferi, Gisbert Peter, Alain Piacentino, Carlo Pompei, Jean-Michel Réess, Jean-Pierre Rivet, Antonio Romano, Natalie Russ, Massimo Santoni, Adelmo Scarpelli, Alain Sémery, Alain Soufflot, Douchane Stefanovitch, Enrico Suetta, Fabio Tarchi, Nazzareno Tonetti, Federico Tosi, Bernd Ulmer.
Abstract
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 microm, 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 approximately 115 km and varies with solar zenith angle over a range of approximately 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.Entities:
Year: 2007 PMID： 18046396 DOI： 10.1038/nature06140
Source DB: PubMed Journal: Nature ISSN： 0028-0836 Impact factor: 49.962