Chlorofluoromethanes in the Environment

TLDR: In this article, the photoprocesses of atmospheric chlorofluoromethanes, including their ultimate sinks, are studied. Butt et al. present a detailed study of the photodissociation process of chlorofluromethane.

Abstract: A study is presented on the photoprocesses of atmospheric chlorofluoromethanes, including their ultimate sinks. Topics covered include: current inventories of atmospheric trichlorofluoromethane and dichlorodifluoromethane, absorption cross-sections for photodissociation of chlorofluoromethanes, mechanisms and quantum yields for photodissociation of CF/sub 2/Cl/sub 2/ and CFCl/sub 3/, solar irradiation flux versus wavelength and altitude, atmospheric diffusion models, chain reactions in the ozone layer, the chloroxyl chains for decomposition of O/sub 3/, abstraction reactions by thermal chlorine atoms, release of Cl atoms by hydroxyl radical attack on hydrogen chloride, methane concentrations at 50 km, rate constants for ClO/sub x/ reactions with O/sub 3/ and oxygen atoms, chain terminating reactions, the importance of symmetrical dioxychloride in the stratosphere, fluorine atom chains, possible removal of chlorofluoromethanes by electron capture and/or ionic reaction, possible chlorofluoromethane removal by reaction with singlet oxygen, hydrolysis of chlorofluoromethanes, possible reactions of chlorofluoromethanes with aerosol particles in the stratosphere, calculated O/sub 3/ depletion by chlorine-containing species, multi-dimensional calculations, feedback in the ozone depletion calculation, increased odd oxygen production with O/sub 3/ depletion, time delay effects in the appearance of O/sub 3/ depletion, time concentration patterns with a one year stepfunction injection of CF/sub 2/Cl/sub 2/ and for several hypothetical models of chlorofluoromethane releasemore » stratospheric concentrations from CF/sub 2/Cl/sub 2/ injected by 1975, estimates of consequences for two different manufacturing patterns for CF/sub 2/Cl/sub 2/ between 1975 and 1990, current stratospheric levels of chlorine-containing compounds, possible biological and climatological effects of stratospheric O/sub 3/ depletion, and observable trends in the average O/sub 3/ concentration of the atmosphere.« less