Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10702235 | Icarus | 2005 | 14 Pages |
Abstract
Titan has been observed with UVES, the UV-Visual Echelle Spectrograph at the Very Large Telescope, with the aim of characterizing the zonal wind flow. We use a retrieval scheme originally developed for absolute stellar accelerometry [Connes, P., 1985. Astrophys. Space Sci., 110, 211-255] to extract the velocity signal by simultaneously taking into account all the lines present in the spectrum. The method allows to measure the Doppler shift induced at a given point by the zonal wind flow, with high precision. The short-wavelength channel (4200-5200 Ã
) probes one scale height higher than the long-wavelength one (5200-6200 Ã
), and we observe statistically significant evidence for stronger winds at higher altitudes. The results show a high dispersion. Globally, we detect prograde zonal winds, with lower limits of 62 and 50 mâsâ1 at the regions centered at 200 and 170 km altitude, but approximately a quarter of the measurements indicates null or retrograde winds.
Keywords
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Space and Planetary Science
Authors
D. Luz, T. Civeit, R. Courtin, J.-P. Lebreton, D. Gautier, P. Rannou, A. Kaufer, O. Witasse, L. Lara, F. Ferri,