MOLECULAR PARAMETERS FOR CARBON DIOXIDE ABSORPTIONS IN THE $3450 cm ^{-1}$ SPECTRAL REGION

Abstract

Line positions and intensities of carbon dioxide transitions between 3400 and about $3500 cm^{-1}$ have been determined from long-path, low-pressure, room-temperature spectra recorded with $0.01 cm^{-1}$ resolution using the Fourier transform spectrometer in the McMath telescope of the National Solar Observatory. Numerous vibration-rotation bands have been identified. The upper level of the $(21^{1}1){III} - (11^{1}0){I}$ band interacts with the $(40^{\circ}0){II}$ vibrational level. A non-linear least squares spectral fitting technique has been applied to all unblended $CO{2}$ lines in these spectra. The pressure ranged from 1 to 10 Torr with an absorption path of up to 385 m. The measured intensities have been analyzed to determine vibrational band intensities and F-factor coefficients for the bands not extending beyond our high frequency limit.