Explicit methods for stiff ODEs from atmospheric chemistry Original Research Article

The subject of research is the numerical integration of atmospheric chemical kinetics systems. The application lies in the study of air pollution, modelled by atmospheric chemistry-transport problems. This application puts high demands on the efficiency of the stiff solver. Three explicit methods are discussed and compared for a selected chemical kinetics system which is representative for the state of the art. The first and the second method are of the explicit QSSA type and the third is based on the two-step backward differentiation formula, combined with Gauss-Seidel iteration to approximately solve the implicitly defined solution. This also renders the method explicit. In the comparison, the two-step method comes out best.