Thermal effects on flow and dispersion over urban areas: Capabilities for prediction by physical modeling

Criteria for physical modeling of urban area heating and thermally stratified, boundary-layer flows approaching the area are summarized. Flow modeling facilities, boundary-layer wind tunnels and a natural convection chamber, developed at Colorado State University that can satisfy the essential criteria are described. Three categories of studies are summarized to illustrate the range of capabilities for physical modeling of flow and dispersion over urban areas: (1) idealized heat island, (2) heat island for a particular urban complex, and (3) mountain-valley drainage flow onto a town. Model data are compared with available field measurements and observations.