Advection-Diffusion Equation with Low Wind in Stable and Unstable Conditions

The separation approach is used to solve the advection-diffusion equation, where the vertical eddy diffusivity and wind speed are functions of the power law of vertical height, and the horizontal eddy diffusivity is a function of the vertical distance "z," which represents the near-source diffusion in weak winds. The performance of the model was evaluated against field testing carried out in the United States at the Prairie-Grass experiment in both stable and unstable conditions.