Implications of NO y emissions from subsonic aircraft at cruise altitude

This is the authors' abstract. We don't add key points for this paper.

The exhaust emissions from civil subsonic aircraft at cruise altitude are important man-made sources that pollute the upper troposphere and the lower stratosphere (8-12 km). The formation of NO y species from NO x , both before and after the exit nozzle, have created increasing environmental concerns. Flight histories of Boeing 747-400 aircraft during the cruise stage between selected city pairs have been simulated using a computer program developed at Cranfield University. The passive distribution of NO x and HNO 3 is calculated using the UGAMP three-dimensional chemical transport model. The sink of NO x , which is HNO 3 , is parameterized using an exponential decay process with an altitude-dependent lifetime. The model also includes transport by advection, vertical diffusion and convection. These simulations for January and July are analysed in terms of the resulting mean volume mixing ratios for both NO x and HNO 3 .