UV and Infrared Absorption Spectra, Atmospheric Lifetimes, and Ozone Depletion and Global Warming Potentials for CCl2FCCl2F (CFC-112), CCl3CClF2 (CFC-112a), CCl3CF3 (CFC-113a), and CCl2FCF3 (CFC-114a)

Abstract. The potential impact of the recently observed CCl2FCCl2F (CFC-112), CCl3CClF2 (CFC-112a), CCl3CF3 (CFC-113a), and CCl2FCF3 (CFC-114a) (chlorofluorocarbons, CFCs), on stratospheric ozone and climate are presently not well characterized. In this study, the UV absorption spectra of these CFCs were measured between 192.5–235 nm over the temperature range 207–323 K. Precise parameterizations of the UV absorption spectra are presented. A 2-D atmospheric model was used to evaluate the CFC atmospheric loss processes, lifetimes, ozone depletion potentials (ODPs), and the associated uncertainty ranges in these metrics. The CFCs are primarily removed in the stratosphere by short wavelength UV photolysis with calculated global annually averaged steady-state lifetimes (years) of 63.6 (61.9–64.7), 51.5 (50.0–52.6), 55.4 (54.3–56.3), and 105.3 (102.9–107.4) for CFC-112, CFC-112a, CFC-113a, and CFC-114a, respectively. The range of lifetimes given in parentheses where obtained by including the 2σ uncertainty in the UV absorption spectra and O(1D) rate coefficients in the model calculations. The 2-D model was also used to calculate the CFC ozone depletion potentials (ODPs) with values of 0.98, 0.86, 0.73, and 0.72 obtained for CFC-112, CFC-112a, CFC-113a, and CFC-114a, respectively. Using the infrared absorption spectra and lifetimes determined in this work, the CFCs global warming potentials (GWPs) were estimated to be 4260 (CFC-112), 3330 (CFC-112a), 3650 (CFC-113a), and 6510 (CFC-114a) for the 100-year time-horizon.