Results of the SCENIC project: impacts of supersonic aircraft emissions upon the atmosphere

of aircraft emissions and impact studies on chemistry and climate) was aimed at quantifying the environmental impact of emissions produced by a supersonic fleet. This paper presents the chemical impact of supersonic aircraft on the strato-spheric ozone background concentration and the possible mitigation of this impact due to changes in aircraft / fleet design. The results of supersonic aircraft emissions is a reduction of ozone in the middle stratosphere (-50 ppbv in 2050). Within the UTLS area different behaviours emerge in the model results. The paper focuses on the crossover-point in the ozone net-production between the “stratospheric ” chemistry and the “tropospheric ” chemistry and the implication upon the aircraft impact calculations. The mitigation study shows that a reduction of speed and reduction of cruise altitude, those two factors are correlated in a supersonic fleet configuration, gives the weakest im-pact on the ozone in all the model calculations.