Measurements of zonal winds on Titan with mm Interferometry: From IRAM PdB to ALMA
Abstract
We report Titans's observations with the IRAM Plateau de Bure Interferometer, between 2003 and 2005. Spectral maps were obtained in the HC3 N(25-24) and CH3 CN(12-11) rotational lines at 227.4 GHz and 220.7 GHz, respectively. An angular resolution of 0.6 arcsec was obtained using the most extended configuration of the six-antenna array, while Titan's apparent diameter was about 1.0 arcsec. These disk-resolved investigation of the Doppler lineshifts, yield to characterize the zonal wind flow in the upper atmosphere. A clear prograde wind direction is determined at the altitude probed (250 and 400 km), through Doppler lineshifts measurements between the east and west. At the altitude of 400 km, is the first direct determination of the mesospheric wind speed. The retrieved zonal wind speeds will be presented. Simulations of expected wind measurements with ALMA in order to measure wind's variations with latitudes will also be shown.
- Publication:
-
European Planetary Science Congress 2006
- Pub Date:
- 2006
- Bibcode:
- 2006epsc.conf..590M