Wind Speed Reduction Induced by Urban Morphology

Accurate prediction of advection and turbulent mixing is fundamental to understanding the transport and deposition of atmospheric pollutants. There is mounting evidence hinting at overestimation of wind speed in the urban airshed by conventional mesoscale NWP models. This has been hypothesized as a factor contributing to air quality models underestimating pollutant concentrations in highly urbanized regions, where the observed wind speed is significantly slower than that predicted. Researchers have proposed that the parametric roughness approach to representing aerodynamic drag and friction induced by urban morphology is inadequate. Specifically, the vertical evolution of momentum deficit developed within, and then propagated above the urban canopy is not realistically captured.