Source-receptor relations from nonlinear atmospheric models

Abstract

Source-receptor relations have been calculated from a nonlinear-chemistry atmospheric model using an auxiliary equation approach similar in form to methods used for sensitivity analysis. The chemicaltransport equations are solved first in the usual fashion without distinguishing between emissions from different sources. Calculated concentrations are used subsequently in a second set of equations which treat only the transport and chemical transformation of the pollutants for which source resolved information is desired. Numerical integration of these equations is facilitated by the presence of common factors and by linearity. The calculation of source-receptor relations for sulfur and nitrogen pollutants is illustrated using a one-dimensional Lagrangian photochemical model. The auxiliary equation approach applies equally well to higher dimension models where there is a greater need for computationally efficient procedures.