Profiles of Titan's high-altitude haze from multiple occultations
Abstract
Haze in Titan's upper atmosphere were observed in Cassini UVIS stellar occultations. Pointing motion, however, impaired the analysis process and only three occultations have been published to date. Most of the occultations are usable, but require special treatment. To address the problem, an innovative analytic method for correcting the effect of pointing motion has been developed using forward modeling of the Cassini/UVIS instrument spectral response function. The Markov Chain Monte-Carlo (MCMC) method has been applied to the analysis by including pointing in the state vector as parameters in the spectral fitting process. In addition to haze, LOS (line-of-sight) abundances of twelve other hydrocarbon and nitrile species are obtained in the analysis. Reduction of high-altitude haze profiles for thirteen occultations has been obtained, most of which have never been analyzed because of pointing motion. The new results provide a 2-D (highly interpolated) regional map of the haze abundance in Titan's upper atmosphere.
- Publication:
-
42nd COSPAR Scientific Assembly
- Pub Date:
- July 2018
- Bibcode:
- 2018cosp...42E1036F