A study of the upper atmosphere of Uranus using the IUE
Encrenaz, T.; Atreya, S. K.; Romani, P. N.; Combes, M.; Fricke, K.
France, United States, Germany
Abstract
The 1750 Å band of C2H2 has been detected in an IUE spectrum of Uranus recorded in 1980. The derived C2H2 column density is 6.8±3.4×1016cm-2. Eddy diffusion coefficients of 104cm2s-1 or smaller at the homopause result in an abundance of photochemically produced C2H2 which is too low compared to the measurements. On the other hand, the results with K = 105 or 106cm-2s-1 are virtually undistinguishable from each other but give acceptable agreement with the data. The observed C2H2 is controlled by photochemistry and not by saturation, which takes place at lower altitudes.