Incorporation of non-linear effective cross-section parameterizations into a fast photolysis computation code (Fast-J)

We have investigated several methods of incorporating laboratory measurements of effective cross-sections (quantum yield times absorption cross-section) that are non-linear functions of temperature, pressure, and wavelength, into the Fast-J photolysis code of Wild et al. (2000). The best method was found to be parameterization of the solar weighted effective cross-section using the form of the effective cross-section, with numerical fitting of the parameterization constants. Using this technique on the acetone data of Gierczak et al. (1998) produces a parameterization which fits all points to within 1%. This method should also benefit other photolysis codes with large wavelength bins.