Thereby retaining the Monin–Obukhov similarity theory The new surface exchange parameterisation is furthermore shown to have a strong impact on the dispersion characteristics of air pollutants in urban areas
A street canyon width and a building density as a function of height The module computes the impact of the horizontal roof and canyon floor and vertical walls surfaces on the wind speed
Takes into account the shadowing and radiation trapping effects induced by the urban canyons The computation of the turbulent length scales in the TKE equation is also modified to take into account the presence of the buildings The parameterisation is introduced into a mesoscale model and tested in a bidimensional case of a city over flat terrain The new parameterisation is shown to be able to reproduce the most important features observed in urban areas better than the traditional approach which is based only on the modification of the roughness length