ABSTRACT
We have performed high-resolution spectral observations at mid-infrared wavelengths of CH4 (8.14 micrometers), C2H6 (12.16 micrometers), and C2H2 (13.45 micrometers) on Jupiter. 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. The observations were performed using our cryogenic echelle spectrometer CELESTE, in conjunction with the McMath-Pierce 1.5-m solar telescope between November 1994 and February 1995. We used the methane observations to derive the temperature profile of the jovian atmosphere in the 1-10 mbar region of the stratosphere. This profile was then used in conjunction with height-dependent mixing ratios of each hydrocarbon to determine global abundances for ethane and acetylene. The resulting mixing ratios are 3.9(+1.9)(-1.3) x 10(-6) for C2H6 (5 mbar pressure level), and 2.3 +/- 0.5 x 10(-8) for C2H2 (8 mbar pressure level), where the quoted uncertainties are derived from model variations in the temperature profile which match the methane observation uncertainties.
Subject(s)
Acetylene/analysis , Atmosphere/chemistry , Ethane/analysis , Jupiter , Methane/analysis , Astronomical Phenomena , Astronomy , Extraterrestrial Environment , Models, Chemical , Photochemistry , Spectrophotometry, Infrared , TemperatureABSTRACT
Scattering losses as low as 0.025 dB/km at 2.55 microm have been measured in short lengths of fluoride-glass optical fiber.These measurements were made on several 5-7-cm lengths of fiber. Measurements were also made at various wavelengths to determine the wavelength dependence of the optical loss.
