Does anyone have absorption coefficients for sulfur dioxide at various wavelengths?
The US National Institute of Standards and Technology is a good source. The following image show absorbance between 2.5 and 32 $\mu$m. For wavelengths shorter than 2.5 $\mu$m, other sources (less reliable) suggest that there is no significant absorption bands. The original data in ASCII JCAMP-DX format can be downloaded here.