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Analysis of Raman scattered LY‐α emissions from the atmosphere of Uranus
Author(s) -
Yelle R. V.,
Doose L. R.,
Tomasko M. G.,
Strobel D. F.
Publication year - 1987
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl014i005p00483
Subject(s) - uranus , atmosphere (unit) , physics , rayleigh scattering , diffuse sky radiation , ultraviolet , scattering , raman scattering , mixing ratio , raman spectroscopy , astronomy , atmospheric sciences , planet , optics , meteorology
A line at 1280 Å, due to Raman scattering of solar Lyman alpha (Ly‐α) in the atmosphere of Uranus, has been detected by the Voyager Ultraviolet Spectrometer. The measured intensity of 40 ± 20 R implies that 200 R to 500 R of the measured 1500 R Ly‐α intensity at the sub‐solar point is due to Rayleigh scattering of the solar line. The presence of Rayleigh and Raman scattering at 1216 Å suggests that the Uranian atmosphere is largely devoid of absorbing hydrocarbons above the 0.5 mbar level. The most natural explanation of this depletion is very weak vertical mixing equivalent to an eddy coefficient on the order of 200 cm² s −1 between 0.5 mbar and 100 mbar.