The dynamics of pollutant dispersion in the lower atmosphere are influenced by obstacles that interrupt the flow. This is typically the case in urban areas with heavy traffic, characterized by “street canyons” and squares surrounded by tall buildings, or in industrial areas with large buildings. In these situations, locally high pollution episodes can occur and must be described using tools that can explicitly consider buildings and their effects at a very fine scale, or microscale. Possible applications of such modeling include accidental releases of toxic substances, pathogenic agents, heavy gases, and radioactive material. Additionally, the dispersion of traditional pollutants in highly urbanized areas, primarily caused by vehicular traffic, is of particular interest.
