Glow discharge induced reactions in mixtures of ozone and chlorodifluoromethane with atmospheric gases

Abstract

The influence of extraterrestrial particles like cosmic radiation (CR) on the chemistry and ozone density in the Earth’s stratosphere is not well investigated and normally neglected in stratospheric chemistry models. Here we present the commissioning of a lab-based apparatus which aims at simulating conditions in the stratosphere in order to get better insight into the reactions induced by the secondary-particle showers from high-energetic CR which can reach low altitudes. Admixtures of ozone and the halocarbon CHClF₂ (R22, chlorodifluoromethane) to atmospheric gases (N₂, O₂, Ar) were exposed to a glow discharge in the total pressure regime of a few hPa. According to the mass spectrometric analysis of the gas composition the discharge initiates significant ozone depletion by a factor four in the absence of R22. This depletion is strongly enhanced to two orders of magnitude in the presence of R22. The possible underlying reactions are discussed.