Stratospheric chlorine partitioning: Constraints from shuttle‐borne measurements of [HCl], [ClNO₃], and [ClO]

Abstract

Measured stratospheric mixing ratios of HCl, ClNO 3 , and ClO from ATMOS and MAS are poorly reproduced by models using recommended kinetic parameters. This discrepancy is not resolved by new rates for the reactions Cl+CH 4 and OH+HCl derived from weighted fits to laboratory measurements. A deficit in modeled [HCl] and corresponding overprediction of [ClNO 3 ] and [ClO], which increases with altitude, suggests that production of HCl between 20 and 50 km is much faster than predicted from recommended rates.