MODELING OF AIRCRAFT ENGINE EXHAUST LOCAL -IMPACT ON THE ATMOSPHERIC COMPOSITION

Contributing to numerous model studies of the sub- and supersonic airc rafts global impact on the atmosphere, this paper is concerned with th e study of separate aircraft engine exhaust effects on yearly averaged atmosphere at the 45 degrees N cruise flight at altitudes of 10, 16 a nd 24 km. A box diffusion photochemical model in the cross-section pla ne of the flight trajectory is applied. It account for heterogeneous r eactions on condensation trail particles in the troposphere and on the sulfate aerosols in the stratosphere. Actual enhanced horizontal disp ersion of the exhaust plume is considered in the model. The initial co mposition and the amount of exhaust were taken the same as in Danilin et al, (1992) to compare the results. Diurnal courses of affected ozon e and other gases in a narrow plume of Danilin et al, (1992) and in a wide plume are calculated for the 24 hours period and for midday and m idnight releases. Model calculations show significant but short-period depletion of ozone with about one hour of 99% restoration period in t he narrow plume. The oxidation of NO and NO2 into HNO3 is insignifican t in all cases, which agree with the results of Danilin et al. (1992) and with recent observations of Arnold et al. (1992). The heterogeneou s photochemistry influences the NO3, N2O5 and HO2 content evolution in the plume considerably.