SIMULATING THE GLOBAL TRANSPORT OF NITROGEN-OXIDES EMISSIONS FROM AIRCRAFT

With the atmosphere general circulation model ECHAM the passive transport of NO(x) emitted from global subsonic air traffic and the NO(x) concentration change due to these emissions are investigated. The source of NO(x) is prescribed according to an aircraft emission data base. The sink of NO(x) is parameterized as an exponential decay process with globally constant life-time. Simulations in perpetual January and July modes are performed. Both the resulting mean and the standard deviation of the NO, mass mixing ratio are analysed. In January horizontal dispersion is more pronounced and vertical mixing is smaller than in July. In both cases the resulting quasi-stationary fields of the mass mixing ratio display a pronounced zonal asymmetry. The variability accounts up to 30% of the mean field.