High-resolution photoabsorption cross-section measurements of SO2 at 295 K between 198 and 220 nm

SO2 is an important constituent of the atmospheres of Io and Venus. Accurate photoabsorption cross‐section data at the temperatures of these planetary atmospheres are required for the interpretation of SO2 observations and for reliable photochemical models. As part of a planned series of measurements over the 160–300 K range, photoabsorption cross sections of SO2 at 295 K, in the wavelength region 198–220 nm, have been determined from very high resolution (resolving power (λ/Δλ) ≈ 450,000) absorption spectra recorded with a vacuum ultraviolet Fourier transform spectrometer. These new measurements are compared with earlier, lower‐resolution (λ/Δλ ≈ 100,000) photoabsorption measurements at 213 K spanning the same wavelength region, with lower‐resolution (λ/Δλ ≈ 100,000) measurements at 295 K in a more limited region, and with a recent Doppler‐limited laser diode measurement at 295 K over a very narrow wavelength region.