Box and Gaussian plume models of the exhaust composition evolution of subsonic transport aircraft in- and out of the flight corridor
- Main Geophysical Observatory, 7 Karbyshev st., St. Petersburg, 194021, Russia
Abstract. A box and a Gaussian plume model including gas-phase photochemistry and with plume dispersion parameters estimated from the few available plume observations are proposed and used for evaluation of photochemical transformations of exhausts from a single subsonic transport aircraft. The effects of concentration inhomogeneities in the plume cross section on the photochemical sources and sinks in the plume are analyzed for various groups of compounds. The influence of these inhomogeneities on the rate and on the mass of ambient air entrainment into the plume are studied also by comparing the box and the Gaussian plume model simulations during the first hours of their "life''. Due to the enterance of HOx and NOx from ambient air into the plume with rates varying from the wind shear and turbulence conditions, the rate of emitted NOx oxidation in the plume is dependent on these and also on the background concentration levels of HOx and NOx.