OXYGEN-INDUCED BROADENING AND LINE SHIFTS IN THE $\nu_{3}$ REGION OF $^{12}CH_{4}$

Author Institution: Department of Physics, College of William and Mary; Atmospheric Sciences Division, NASA Langley Research CenterA series of high-resolution room temperature spectra were recorded with dilute mixtures (1\%) of methane in oxygen using the McMath Fourier transform spectrometer located at the National Solar Observatory on Kitt Peak. All spectra were obtained at 0.01-$cm^{-1}$ resolution covering the 2650-3200 $cm^{-1}$ spectral region; a 25-cm stainless steel absorption cell was used. Total sample pressures, which ranged between 100 and 400 Torr, were continuously monitored. Oxygen broadening and pressure-induced line shift coefficients for $^{12}CH_{4}$ lines were deduced by analyzing these spectra with a nonlinear least-squares method. Results were obtained for over 200 transitions in the $v_{3}$ pentad. These results will be compared to similar work previously reported for air and nitrogen broadening of $^{12}CH_{4}$ in the same spectral region and for oxygen broadening of the same transitions in $^{13}CH_{4}$