The detection of benzene in Saturn's upper atmosphere

• Published in: Geophysical Research Letters
• Main Authors: Koskinen, T. T., Moses, J. I., West, R. A., Guerlet, S., Jouchoux, A.
• Other Authors: Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2016
• Subjects: Saturn; photochemistry; [SDU]Sciences of the Universe [physics]; polar night
• Online Access: https://insu.hal.science/insu-03727105; https://insu.hal.science/insu-03727105/document; https://insu.hal.science/insu-03727105/file/Geophysical%20Research%20Letters%20-%202016%20-%20Koskinen%20-%20The%20detection%20of%20benzene%20in%20Saturn%20s%20upper%20atmosphere.pdf; https://doi.org/10.1002/2016GL070000

International audience The stratosphere of Saturn contains a photochemical haze that appears thicker at the poles and may originate from chemistry driven by the aurora. Models suggest that the formation of hydrocarbon haze is initiated at high altitudes by the production of benzene, which is followed by the formation of heavier ring polycyclic aromatic hydrocarbons. Until now there have been no observations of hydrocarbons or photochemical haze in the production region to constrain these models. We report the first vertical profiles of benzene and constraints on haze opacity in the upper atmosphere of Saturn retrieved from Cassini Ultraviolet Imaging Spectrograph stellar occultations. We detect benzene at several different latitudes and find that the observed abundances of benzene can be produced by solar-driven ion chemistry that is enhanced at high latitudes in the northern hemisphere during spring. We also detect evidence for condensation and haze at high southern latitudes in the polar night.