Venus atmosphere dynamics: A continuing enigma
Bougher, S. W.; Del Genio, A. D.; Limaye, S. S.; Schubert, G.; Covey, C. C.; Grossman, A. S.; Hollingsworth, J. L.; Young, R. E.
United States
Abstract
The dynamics of the Venus atmosphere presents a major unsolved problem in planetary science: the so-called superrotation of the lower atmosphere and its transition to a subsolar-to-antisolar circulation in the upper atmosphere. (In this paper we place the dividing line between the lower and upper atmosphere at 90-100 km altitude (pressure 0.39 to 0.028 mbar), the base of the day-side thermosphere.) Superrotation has also been observed in the atmosphere of Titan, the only other slowly rotating world with a substantial atmosphere known at present; in this case also the transition to a different circulation in the upper atmosphere is also apparent but not well understood. Thus, the issues discussed below may be generic to any slowly rotating terrestrial planet's atmosphere.