Spectroscopy and chemistry of the atmosphere of UranusA comprehensive review of the chemistry and spectroscopy of the Uranian atmosphere is presented by means of earth-based, earth-orbital, and Voyager 2 observations covering the UV, visible, infrared, and radio wavelength regions. It is inferred from these observations, in concert with the average density of about 1.3 g/cu cm, that the Uranian atmosphere is enriched in heavy elements relative to solar composition. Pre-Voyager earth-based observations of CH4 bands in the visible region and Voyager radio occultation data imply a CH4/H2 volume mixing ratio of about 2 percent corresponding to an enrichment of approximately 24 times the solar value of 0.000835. In contrast to CH4, microwave observations indicate an apparent depletion of NH3 in the 155-to-200-K region of the atmosphere by 100 to 200 times relative to the solar NH3/H2 mixing ratio of -0.000174. It is suggested that the temporal and latitudinal variations deduced for the NH3/H2 mixing ratio in this region of the Uranian atmosphere are due to atmospheric circulation effects.
Document ID
19920036082
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Fegley, Bruce, Jr. (Max-Planck-Institut fuer Chemie Mainz, Federal Republic of Germany, United States)
Gautier, Daniel (Paris Observatoire, Meudon, France)
Owen, Tobias (Hawaii, University Honolulu, United States)
Prinn, Ronald G. (MIT Cambridge, MA, United States)