|
|||||
|
|
Characterization of zonal winds in the stratosphere of Titan with UVES |
|
| Authors: | D Luz T Civeit J-P Lebreton P Rannou O Witasse F Ferri |
| Institution: | a Observatoire de Paris-Meudon, 5 Place Jules Janssen, 92195 Meudon Cedex, France b Centro de Astronomia e Astrofísica da Universidade de Lisboa, Tapada da Ajuda, 1349-018 Lisboa, Portugal c Research and Scientific Support Department of ESA, ESTEC, Kepplerlaan 1, P.O. Box 299, 2200 AG Noordwijk, The Netherlands d Service d'Aéronomie/IPSL, Université Versailles-St.-Quentin, BP3-91371 Verrieres le Buisson, France e European Southern Observatory, Alonso de Cordova 3107, Casilla 19001, Santiago 19, Chile f Instituto de Astrofísica de Andalucía/CSIC, Camino Bajo de Huetor 50, 18008 Granada, Spain g CISAS/Universitá di Padova, Via Venezia 1, 35131 Padova, Italy |
| 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 Å) probes one scale height higher than the long-wavelength one (5200-6200 Å), 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 m s−1 at the regions centered at 200 and 170 km altitude, but approximately a quarter of the measurements indicates null or retrograde winds. |
| Keywords: | Titan Atmospheres Dynamics |
| 本文献已被 ScienceDirect 等数据库收录！ | |