15min:

D. CHRIS BENNER, V. MALATHY DEVI, Department of Physics, College of William and Mary, Box 8795, Williamsburg, VA 23187-8795; MARY ANN H. SMITH, CURTIS P. RINSLAND, Atmospheric Sciences Division, MS 401A, NASA Langley Research Center, Hampton, VA 23681-2199; GUY GUELACHVILI, Laboratoire de Physique Moleculaire et Applications, CNRS, Universite Paris Sud, Batiment 350, 91405 ORSAY-Cedex, France; LINDA R. BROWN, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109.

Over 40 high-resolution absorption spectra of methane as previously described were recorded. Included in the spectra recorded at Kitt Peak were room temperature spectra of methane highly enriched in ¹³CH₄ broadened by air and having a 5 cm path length. All of these spectra were simultaneously fitted in order to obtain spectral line parameters in the ₃ spectral region of ¹²CH₄ and ¹³CH₄. In order to obtain reasonable fits, it was necessary to include line mixing within the rotational manifolds. Line mixing was only required between spectral lines of the same species of methane. All of the P branch has been measured and measurement of the R branch is in progress. Mixing coefficients for the two isotopes and the two branches will be compared. It was also possible in a few cases to measure the line mixing coefficients between pairs of spectral lines belonging to the ₂+₄ band.