On the use of adaptive gridding methods for modelling chemical transport from multi-scale sources

This paper investigates the solution of atmospheric reaction/flow problems using time-dependent adaptive mesh gridding techniques. Preliminary studies of time varying problems in two space dimensions related to the effects of power station emissions on regional ozone levels have been carried out. The results show the importance of using adaptive grids in order to represent the interaction of the plume with background air over large distances. The adaptive mesh reveals features of cross wind concentration profiles which would not be shown using the standard mesh sizes adopted in regional atmospheric calculations. As the level of adaptivity increases, and the mesh becomes locally refined in regions of large spatial error, the total and peak ozone concentrations change quite significantly. The results demonstrate that the level of error which can result from using fixed or telescopic grid approaches for spatially inhomogeneous source patterns may be significantly reduced by the use of adaptive meshes.