A semi-analytical solution for the three-dimensional advection–diffusion equation considering non-local turbulence closure

Atmospheric air pollution turbulent fluxes can be assumed to be proportional to the mean concentration gradient. This assumption, along with the equation of continuity, leads to the advection–diffusion equation. Moreover, large eddies are able to mix scalar quantities in a manner that is counter to the local gradient. In this work we present a semi-analytical solution for the three-dimensional steady-state advection–diffusion equation, considering non-local turbulence closure using the Generalized Integral Advection Diffusion Multilayer Technique (GIADMT). We report some examples of applications of the new solution for two different datasets and for a water tank experiment.