Vertical profiles of mean flow and turbulence characteristics in a downtown street canyon measured during Joint Urban 2003

The paper presents results from sonic measurements at two towers operated in a downtown street canyon (Park Avenue) of Oklahoma City during Joint Urban 2003. The analysis focuses on situations with winds approximately perpendicular to the street (southerly winds). The data are compared to results observed in previous field and laboratory studies and it is discussed to what extent the flow patterns resemble street-canyon vortices re-circulating inside the street. Such flow regimes are considered to by typical for situations with long buildings on both sides of the street, and street-canyon dispersion models are often based on some type of vortex parameterization. However, previous studies have shown that the building and roof geometries strongly influence the vortex dynamics. For configurations with variable building heights a typical street-canyon vortex often does not develop. The buildings heights along Park Avenue are quite variable and first results indicate that two tall building towers at the western end of the study section, as well as low-rise buildings on the northern side of the street strongly alter the canopy flow patterns. The influence of vegetation and traffic in Park Avenue on the flow and turbulence structure will also be addressed.