Spectroscopic measurements of SO2 line parameters in the 9.2 micron atmospheric region and theoretical determination of self-broadening coefficients

Sulfur dioxide is still the subject of numerous spectroscopic studies since it plays an active role in the chemistry of Earth’s atmosphere and it is a molecule of proven astrophysical importance. In the present work we have determined the self-broadening and integrated absorption coefficients for several lines in the v1 band spectral region around 9.2 micron. Besides the parameters of the lines belonging to the v1 fundamental of (32)SO2, also those for some rovibrational lines of the v1+v2 −v2 hot band of the (32)SO2 isotopologue and the v1 band of the (34)SO2 isotopic species have been determined. The measurements have been carried out at 297 K using a tunable diode laser spectrometer. The self-broadening parameters have also been theoretically determined employing a semiclassical formalism based on the Anderson–Tsao–Curnutte approximation. The study has been completed with the determination of the vibrational cross sections of the three fundamental bands measured from the spectra recorded at a resolution of 0.2 cm−1 using a Fourier transform infrared spectrometer.