Urban Dispersion Processes Investigated During the Joint Urban 2003 Study in Oklahoma City

The Joint Urban 2003 study was a major urban tracer/meteorological study conducted in Oklahoma City beginning June 28, 2003 and ending July 31, 2003. Ten intensive operation periods (IOPs) were completed during this 34-day study period where sulfur hexafluoride tracer was released in downtown Oklahoma City and sampled during an 8-h period in and around downtown and as far as 4 km downwind. During four of the ten IOPs the infiltration of tracer into four downtown buildings were studied. Winds and other meteorological quantities were measured continuously at nearly 200 locations in and around downtown Oklahoma City during July 2003. Tracer was sampled using over 200 integrated samplers and 25 fast response analyzers. Vertical measurements of tracer were made by placing samplers on the tops of nearly 20 buildings and using a 90 m crane with tracer sampled at seven levels.

An overview of results from the tracer releases will be presented and discussed including evidence of immediate vertical mixing, street-canyon channeling, urban canopy retention and sudden plume redirection.