ATMOSPHERIC FATE OF SEVERAL HYDROFLUOROETHANES AND HYDROCHLOROETHANES .2. UV ABSORPTION CROSS-SECTIONS AND ATMOSPHERIC LIFETIMES

The temperature dependent UV absorption cross-sections of the hydrochlorofluoroethanes CF3CHFCl, CH3CF2Cl, and CF3CHCl2 are reported. The UV absorption cross-sections were measured over the temperature range 203 to 295 K and the wavelength range 190 to 230 nm. The hydrofluorocarbons CH3CF2H and CF3CH2F were also studied at 295 K and upper limits for their UV absorption cross-sections over the wavelength range 190 to 230 nm were obtained. The atmospheric lifetimes of these species were calculated using a one-dimensional atmospheric model, using the kinetic data obtained in the previous paper (Gierczak et al. 1991) and the absorption cross-section data obtained in the present study.