REPRESENTATION OF LOCALIZED AIRCRAFT NOY EMISSIONS IN A 2-DIMENSIONALMODEL OF STRATOSPHERIC OZONE

Oxides of nitrogen deposited into the lower stratosphere by supersonic aircraft dan affect ozone. The effect can be estimated using two-dime nsional chemistry-transport models in which the transport of the depos ited material is simulated by zonal-mean advection and eddy transport. In these assessment studies, the localized three-dimensional injectio n is usually introduced into the model simply by specifying the zonal average of the actual three-dimensional sources as input to the model. In the presence of substantial stratospheric wave activity, this proc edure may be inaccurate as the emissions will rapidly be transported a way from the initial locations through short-term processes not incorp orated in two-dimensional transport parameterizations. Here we use a p otential vorticity/potential temperature mapping technique to determin e the effective zonally averaged sources appropriate for input to a tw o-dimensional model. Using projected source scenarios for NOy emission s and a two-dimensional chemistry transport model, we conclude that th is effect has little impact on projections of ozone depletion.