Behaviour of tracer diffusion in simple atmospheric boundary layer models

[摘要] 1-D profiles and time series from an idealised atmospheric boundary layermodel are presented, which show agreement with boundary layer measurementsof polar NO_x. Diffusion models are increasingly being used as theframework for studying tropospheric air chemistry dynamics. Models based onstandard boundary layer diffusivity profiles have an intrinsic behaviourthat is not necessarily intuitive, due to the variation of turbulentdiffusivity with height. The simple model presented captures the essence ofthe evolution of a trace gas released at the surface, and thereby providesboth a programming and a conceptual tool in the analysis of observed tracegas evolution. A time scale inherent in the model can be tuned by fittingmodel time series to observations. This scale is then applicable to the morephysically simple but chemically complex zeroth order or box models ofchemical interactions.

[学科分类] 大气科学