Seasonal and latitudinal distribution of trace gases in the stratosphere: Results from a 2D residual circulation model

Abstract

Results for minor stratospheric constituents using a 2D model with self-consistent transport parameters are reported. The meridional circulation is obtained from the output of the MIT-GIT 3D stratospheric model (Cunnold et al., 1975). Consistent data from the same model are used to evaluate the diffusive tensors following the formalism of Holton (1981) and Tung (1982). Chemical damping is consequently taken into account, so that the entire model is built in a selfconsistent manner at the least with the 3D model and no ad hoc assumptions are made with respect of transport parameters. This version of the model represents a major improvement on previous work (Pitari and Visconti, 1984), which used to much too simple chemistry. Results are compared whenever possible with available experimental data, with particular emphasis on chemical reacting species. This comparison shows in general an agreement which is qualitatively similar to the one obtained from classical Eulerian models where transport parameters are often tuned to long-lived tracers without any sound physical basis.