[Previous] | [Session 43P] | [Next]

[43P.11] Observations of C2H6 and C2H2 in the Stratosphere of Saturn

Pedro Sada (Univ. de Monterrey), G. L. Bjoraker, D. E. Jennings, G. H. McCabe, P. N. Romani (NASA-GSFC)

We performed high-resolution (\lambda/\Delta\lambda ~ 2,000) spectral observations at mid-infrared wavelengths of C₂H₆ (12.16 \mum) and C₂H₂ (13.45 \mum)on Saturn during November and December 1994. These emission features probe the stratosphere of the planet and provide information on the carbon-based photochemical processes taking place in that region of the atmosphere. We used CELESTE, a Goddard-developed cryogenic echelle spectrometer, in conjunction with the 1.5-m McMath-Pierce Solar Telescope (NSO/NOAO) at Kitt Peak National Observatory.

For our initial analysis we have used the average temperature profile derived from the Voyager Radio Occultation Experiment, and constant mixing ratios throughout the atmosphere for the hydrocarbons. Preliminary global abundances (excluding polar regions) are 5.0x10^-6 for ethane and 2.5x10^-7 for acetylene.

For this presentation we will refine these results by using an updated temperature profile derived from Voyager-IRIS methane observations of the same latitude range as our measurements. We will also use altitude-dependent hydrocarbon mixing ratios derived from recent photochemical models.