Two-Dimensional Model Calculation of Fluorine-Containing Reservoir Species in the Stratosphere

Two-dimensi•,nal model calculations have been carried out of the distributions of the fluorinecontaining reservoir species HF, CF2 O, and CFC10. HF constitutes the largest fluorine reserr, fir in the stratosphere, but CF• O also makes an important contribution to the inorganic fluorine budget. CFC10 amounts are most irnportant in the tropical lower stratosphere. HF amounts increase with altitude throughout the stratosphere, while those of CF20 and CFC10 fall off above their mixing ratio peaks due to photolysis. The model is in good qualitative agreement with observed vertical profiles of HF and CFeO but tends to underestimate the total column of HF. The calculated CFC10 distribution is in good agreement with the very limited data. The disagreement in the HF columns is likelydue to small inaccuracies in the model's treatment of lower stratospheric ph•,tolysis of chlorofluorocarbons. The model results support the suggestion that CF•O may be heterogeneously c•nverted to HF on the surface of polar stratospheric cloud particles. The model results also suggest that the quantum yield for photolysis of CF:• O is near unity.