A turbulent energy model for diffusion in the convective boundary layer

A turbulent energy model developed by the authors to describe atmospheric flows is used to study diffusion in the convective boundary layer. The model is based on the turbulent energy transport equation coupled with eddy diffusivity expressions for momentum and heat transfer. The diffusion model assumes equality of the eddy diffusivity for heat and mass and Gaussian diffusion in the cross-stream direction. The model is shown to reproduce satisfactorily the main features of diffusion in convective flows, and its predictions compare well with the measurements of the laboratory experiments of Willis and Deardorff, as well as with field data.