Measurements of turbulence in the urban environment

Profiles of mean flow and turbulence have been measured at two sites: one between two long buildings which formed an `idealised' canyon; the other within Birmingham, a typical UK city, as part of the URGENT Programme. Two sonic anemometers were deployed: one fixed above the level of the buildings and a second which was used to measure vertical profiles. The goal was to determine the coupling of the turbulence within the street with turbulence above the buildings, which we suggest controls dispersion within street canyons. The two sonics made synchronised measurements, allowing the coupling to be investigated. Results from both sites will be presented, thus comparing flow in an "idealised" canyon with flow within typical UK street geometry.