[en] 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(1) and ground-based(2-4) observations of infrared emission from CO2, O-2 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(1) owing to a lack of data and of an adequate observing geometry(5,6). Here we report measurements of day-side CO2 non-local thermodynamic equilibrium emission at 4.3 mu m, extending from 90 to 120 km altitude, and of night-side O-2 emission extending from 95 to 100 km. The CO2 emission peak occurs at similar to 115 km and varies with solar zenith angle over a range of similar to 10 km. This confirms previous modelling(7), and permits the beginning of a systematic study of the variability of the emission. The O-2 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(8).
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Drossart, P.
Piccioni, G.
Gérard, Jean-Claude ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
scite shows how a scientific paper has been cited by providing the context of the citation, a classification describing whether it supports, mentions, or contrasts the cited claim, and a label indicating in which section the citation was made.
Bibliography
Bougher, S. W., Alexander, M. J. & Mayr, H. G. Upper atmosphere dynamics: global circulation and gravity waves. In Venus II: Geology, Geophysics, Atmosphere, and Solar Wind Environment (eds Bougher, S. W. Hunten, D. M. & Philips R. J.) 259-292 (Univ. Arizona Press, Tucson, 1997).
Connes, P. Noxon, J. F., Traub, W. A. & Carleton, N. O2 1Δ emission in the day and night airglow of Venus. Astrophys. J. Lett. 233, L29-L32 (1979).
Crovisier, J. et al. Carbon monoxide emissions at 4.7μm from Venus' atmosphere. Planet. Space Sci. 54, 1398-1414 (2006).
Lellouch, E. et al. Monitoring of mesospheric structure and dynamics. In Venus II: Geology, Geophysics, Atmosphere, and Solar Wind Environment (eds Bougher, S. W. Hunten, D. M. & Philips R. J.) 295-324 (Univ. Arizona Press, Tucson, 1997).
Drossart, P. et al. Scientific goals for the observation of Venus by VIRTIS on ESA/Venus Express mission. Planet. Space Sci. doi:10.1016/j.pss.2007.01.03 (in the press).
Lopez-Valverde, M. A., Drossart, P., Carlson, R., Mehlman, R. & Roos-Serote, M. Non-LTE infrared observations at Venus: From NIMS/Galileo to VIRTIS/Venus Express. Planet. Space Sci. doi:10.1016/j.pss.2007.01.008 (in the press) (2007).
Roldan, C., Lopez-Valverde, M. A., Lopez-Puertas, M. & Edwards, D. P. Non-LTE infrared emissions of CO2 in the atmosphere of Venus. Icarus 147, 11-25 (2000).
Crisp, D. et al. Ground-based near-infrared observations of the Venus nightside: 1.27-μm O2(1Δg) airglow from the upper atmosphere. J. Geophys. Res. 101, 4577-4594 (1996).
Piccioni, G. et al. South-polar features on Venus similar to those near the north pole. Nature doi:10.1038/nature06209 (this issue).
Titov, D. V. et al. Venus Express science planning. Planet. Space Sci. 54, 1279-1297 (2006).
Lellouch, E. et al. The 2.4-45μm spectrum of Mars observed with the infrared space observatory. Planet. Space Sci. 48, 1393-1405 (2000).
Picard, R. H., Wintersteiner, P. P., Hegblom, E. R. & Richards, E. Remote sensing of discrete stratospheric gravity-wave structure at 4.3-μm from the MSX satellite. Geophys. Res. Lett. 25, 2809-2812 (1998).
Formisano, V., Maturilli, A., Giuranna, M., D'Aversa, E. & Lopez-Valverde, M. A. Observations of non-LTE emission at 4-5 microns with the planetary Fourier spectrometer aboard the Mars Express mission. Icarus 182, 51-67 (2006).
Lopez-Valverde, M. A. & Lopez-Puertas, M. A non-local thermodynamic equilibrium radiative transfer model for infrared emissions in the atmosphere of Mars. 1. Theoretical basis and nighttime populations of vibrational states. J. Geophys. Res. 99, 13093-13115 (1994).
Keating, G. M. et al. Models of Venus neutral upper atmosphere: Structure and composition. Adv. Space Res. 5, 117-171 (1985).
Ohtsuki, S. et al. Ground-based observation of the Venus 1.27-μm O2 airglow. Adv. Space Res. 36, 2038-2042 (2005).
Similar publications
Sorry the service is unavailable at the moment. Please try again later.
This website uses cookies to improve user experience. Read more
Save & Close
Accept all
Decline all
Show detailsHide details
Cookie declaration
About cookies
Strictly necessary
Performance
Strictly necessary cookies allow core website functionality such as user login and account management. The website cannot be used properly without strictly necessary cookies.
This cookie is used by Cookie-Script.com service to remember visitor cookie consent preferences. It is necessary for Cookie-Script.com cookie banner to work properly.
Performance cookies are used to see how visitors use the website, eg. analytics cookies. Those cookies cannot be used to directly identify a certain visitor.
Used to store the attribution information, the referrer initially used to visit the website
Cookies are small text files that are placed on your computer by websites that you visit. Websites use cookies to help users navigate efficiently and perform certain functions. Cookies that are required for the website to operate properly are allowed to be set without your permission. All other cookies need to be approved before they can be set in the browser.
You can change your consent to cookie usage at any time on our Privacy Policy page.