The Lagrangian chemistry and transport model ATLAS: validation of advective transport and mixing

[摘要] We present a new global Chemical Transport Model (CTM) with fullstratospheric chemistry and Lagrangian transport and mixing called ATLAS(Alfred Wegener InsTitute LAgrangian Chemistry/Transport System). Lagrangian(trajectory-based) models have several important advantages over conventionalEulerian (grid-based) models, including the absence of spurious numericaldiffusion, efficient code parallelization and no limitation of the largesttime step by the Courant-Friedrichs-Lewy criterion. The basic concept oftransport and mixing is similar to the approach in the commonly used CLaMSmodel. Several aspects of the model are different from CLaMS and areintroduced and validated here, including a different mixing algorithm forlower resolutions which is less diffusive and agrees better with observationswith the same mixing parameters. In addition, values for the vertical andhorizontal stratospheric bulk diffusion coefficients are inferred andcompared to other studies. This work focusses on the description of thedynamical part of the model and the validation of the mixing algorithm. Thechemistry module, which contains 49 species, 170 reactions and a detailedtreatment of heterogeneous chemistry, will be presented in a separate paper.

[学科分类] 天文学(综合)