ABSTRACT
A street canyon is a space between buildings, and very complex phenomena are observed within such a space. Street canyon flows are highly turbulent flows, and they depend strongly on building configurations and meteorology. In the daytime, building surface and street bottom are heated by solar radiation. Harmful gases and aerosols are emitted from automobiles or transported from elsewhere into street canyons. These materials interact and are dispersed in street canyons in the presence of turbulent flow. People living in cities are directly exposed to the street canyon environment, which typically has a negative impact on their health because of the poor air quality in street canyons. Accidental or intentional releases of toxic chemicals in street canyons must be dealt with. Urban planning can benefit greatly from information on the climate of street canyons, such as microscale wind and temperature fields.
