Photochemical oxidation of halocarbons in the troposphere

Seasonal and diurnal variations of atmospheric peroxyacetyl nitrate, peroxypropionyl nitrate, and carbon tetrachloride in Beijing

“…CCl 4 is chemical inert in the troposphere, difficult to photolysis and non-reactive towards the tropospheric oxidants (Cox et al, 1976). Therefore, the emitted CCl 4 can ultimately diffuse into the stratosphere where it will release chlorine atoms under the intensive ultraviolet sunlight irradiation and participate in stratospheric ozone depletion (Molina and Rowland, 1974).…”

Chemistry of Stratospheric Chlorine

“…The reactions with O(1D) and OH are found to be negligible in the stratosphere on the basis of the kinetic data from Pitts et al (1974), Jayanty et al (1975a, b), Davis (1975), Atkinson et al (1975), Howard and Evenson (1976), and Cox et al (1976). These reactions also operate in the troposphere, though very slowly; they must be rare sinks of the chlorocarbons in the troposphere like the destructions by lightning discharge and by reactions with ions.…”

“…The mixing ratios at the lower boundary are adopted as 0.1, 0.2, 0.1 and 0.5 ppbV for CFCl3, CF2Cl2, CCl4 and CH3Cl, respectively. These values are based on measurements in the non-urban troposphere by Lovelock (1971Lovelock ( , 1972Lovelock ( , 1974Lovelock ( , 1975, Lovelock et al (1973), Wilkniss et al (1973Wilkniss et al ( , 1975a, Su and Goldberg (1973), Simmonds et al (1974), Hester et al (1974Hester et al ( , 1975a, Grimsrud and Rasmussen (1975a, b), Zafonte et al (1975), and Cox et al (1976).…”

“…Chlorocarbons such as CHCl3, CH2Cl2, CH3CCl3, CHClCCl2, and CCl2CCl2 have been found in the troposphere to be of volume mixing ratio in the order of 10-11 (Lovelock, 1974;Grimsrud and Rasmussen, 1975b;Cox et al, 1976). These species are believed to be of industrial origin.…”

Rate Constants for the Reaction of OH with Halocarbons in the Presence of O2+ N2

“…8 but with one exception, 6 all were made in the presence of inert gases, rather than oxygen and nitrogen mixtures as occurs in the atmosphere. Although it is not likely that these reactions are sensitive to the presence of different "third bodies," greater confidence could be placed in the rate data when applied to atmospheric chemistry, if the "third body" independence were established.…”