Line intensity and self-broadening investigations in the ν1 and ν3 bands of SO2

Abstract

Line intensities and self-broadening coefficients were measured for 37 transitions in the ν1 band of SO2 between 1072 and 1149cm−1 in the rotational quantum number range between 3≤J″≤44 and 0≤Ka″≤23 and for 12 transitions in the ν3 band of SO2 near 1321cm−1 in the rotational quantum number range between 50≤J″≤61 and 2≤Ka″≤18. The experiments were carried out with a dual-channel lead–salt diode-laser spectrometer, which was operated in pulsed mode. The spectroscopic parameters for the individual lines were determined from the analysis of spectra measured in the pressure range between 1 and 12Torr. The measured data of a complete pressure series were analyzed at once. Therefore, the fit delivered directly the self-broadening coefficients and the line intensities. The determined self-broadening coefficients are within the uncertainties in good agreement with previously published data and confirm the typical decrease of the self-broadening coefficient γSO2–SO2 with increasing rotational quantum number Ka″. The broadening coefficients decrease from a γSO2–SO2 by about 0.4cm−1/atm for lines with small Ka″down to values of about 0.2cm−1/atm for lines with a Ka″>18. The line intensities determined here were slightly smaller compared to the data listed in the HITRAN 1996 database. The deviations do not show any remarkable quantum number dependence. The average values of the ratio SiExp/SiHITRAN 1996 were calculated to 0.83±0.02 (ν1 band) and 0.75±0.03 (ν3 band). The integrated band intensities were determined to (3.41±0.11)×10−18cm−1/moleculecm−2 for the ν1 band and to (2.40±0.15)×10−17cm−1/moleculecm−2 for the ν3 band, respectively.