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Lorentz half width and pressure-induced shift coefficients, and speed dependence parameters for oxygen-broadened CO2 transitions in the 30013←00001 (6227 cm-1) and 30012←00001 (6348 cm-1) bands were measured employing a non linear least squares multispectrum fitting technique. The high-resolution spectra used in the analysis were recorded using the McMath-Pierce Fourier transform spectrometer (FTS) located at the National Solar Observatory (NSO) on Kitt Peak, Arizona. The spectra were obtained at room temperature using the long path, 6 m base path White cell available at NSO. The multispectrum fitting algorithm employing Voigt line profiles was modified to include line mixing and speed dependence and was used to fit simultaneously a total of 19 spectra in the 6120-6280 cm-1 and 6280-6395 cm-1 spectral regions. The results from the present study have been compared with measurements available in the literature. Combining the O2-broadening measurements from present work with the previously determined air-broadening results, N2-broadened width and shift coefficients are calculated and compared with other reported values. [ABSTRACT FROM AUTHOR]

Ethane is a prominent contributor to the spectrum of Titan, particularly in the region of the ν9 band at 12 μm. A multispectrum nonlinear least squares fitting program was applied to laboratory spectra of ethane to measure accurate positions, absolute intensities, N2- and self-broadened half-width coefficients and their temperature dependences for a large number transitions. These measurements include several pQ and rQ sub-bands (and other sub-bands such as pP, rR) in the ν9 fundamental band of 12C2H6 centered near 822 cm-1. Positions and intensities were measured for 3771 transitions. N2- and self-broadened half-width coefficients were determined for over 1700 transitions while temperature dependence exponents were retrieved for over 1350 of those transitions. Of these, many measurements (mostly line positions and intensities) belong to the 12C2H6ν9+ν4-ν4 and the ν9+2ν4-2ν4 hot bands, 13C12CH6 ν9 band and unidentified transitions. Forty-three high resolution (0.0016-0.005 cm-1) infrared laboratory absorption spectra recorded at temperatures between ∼150 and 298 K were fitted simultaneously to retrieve these parameters. [ABSTRACT FROM AUTHOR]

We present a detailed spectroscopic study of carbon dioxide in support of atmospheric remote sensing. We have studied two weak absorption bands near the strong ν2 band that is used to derive atmospheric temperature profiles. We have analyzed our laboratory spectra recorded with the synchrotron and globar sources with spectral line profiles that reproduce the absorption features with high accuracy. The Q-branch transitions exhibited asymmetric line shape due to weak line-mixing. For these weak transitions, we have retrieved accurate experimental line strengths, self- and air-broadening, self- and air-induced shift coefficients and weak line mixing parameters. The experimental precision is sufficient to reveal inherent variations of the width and shift coefficients according to transition quantum numbers. [ABSTRACT FROM AUTHOR]