The stratospheric abundance of peroxynitric acid

Abstract

A recent re‐examination of the kinetics of the reaction of NO 2 with HO 2 shows this to be a three body reaction leading to the formation of peroxynitric acid (HO 2 NO 2 ). The rate of formation is such that significant concentrations of HO 2 NO 2 (not previously included in atmospheric models) are expected to form in the stratosphere. In the present study a preliminary determination of the absorption cross section of HO 2 NO 2 is presented. This information is used to calculate theoretical vertical concentration profiles for HO 2 NO 2 . It is concluded that peak mixing ratios should be in the range of 1‐3 ppb at 30 km, and that it should be possible to detect this new stratospheric species using infrared techniques.