The sensitivity of mesoscale chemistry transport model results to boundaryvalues

Using a high resolution meteorology-chemistry transport model, simulations were performed to estimate the sensitivity of the model results to nesting. The model results are compared with airplane measurements made during the TRACT field measuring campaign in September, 1992. For the meteorological p art of the model the performance is enhanced using one-way nesting in a lar ger scale model, if the quality of the large scale driving data is sufficie nt. The sensitivity of the NOx concentration results with respect to nestin g of chemical quantities is rather low due to the poor quality of the forci ng data. A correct description of the emission rates and the meteorological conditions may be more important. For ozone, the best results can be achie ved with either no nesting or a meteorological and chemical nested model si mulation, which is again a result of the poor quality of the forcing data.