Refined 3-d Transport and Horizontal Diffusion for the REM/CALGRID Air Quality Model | Umweltbundesamt

The REM/CALGRID model's available advection schemes have numerical diffusivities that are sufficiently low that one must be concerned about: (a) adding back some horizontal diffusion appropriate to the atmospheric conditions being modeled; and (b) operator-splitting and shear flow errors, heretofore buried by the numerical diffusion.