Toward Numerical Simulation

Abstract

This chapter aims at reviewing the fundamentals of numerical simulation for the physical processes described in the previous chapters. The reactive dispersion equation is formulated for averaged variables in Sect. 6.1. The underlying model hierarchy (from Gaussian models to three-dimensional Eulerian chemistry-transport models) is then presented. Section 6.2 is devoted to the fundamentals of numerical analysis required for the chemistry-transport models. Attention is paid to operator splitting in Sect. 6.2.1, time integration of chemical kinetics in Sect. 6.2.2, and advection in Sect. 6.2.3. The numerical simulation of aerosol dynamics is investigated in Sect. 6.3. To conclude, high-level methods, such as the propagation of uncertainties or data assimilation (coupling between the model outputs and the measured data in order to constrain the simulation), are briefly introduced in Sect. 6.4.