Fast and efficient solution methods for ozone chemistry

Two special-purpose solvers for chemical kinetics problems, a QSSA method and TWOSTEP, together with the state-of-the-art stiff solver VODE, provided with sparse matrix routines, are considered for application in an atmospheric model. Of all three methods a short description is given. A comparison is made for a chemical model describing (parametrized) ozone chemistry. The code TWOSTEP turns out to be a good alternative for the QSSA solver as regards accuracy and to outperform VODE with respect to computation time for accuracies near 1.