An inter-comparison of diagnostic urban wind flow models based on the Röckle methodology using the Joint Urban 2003 field data

Several groups have developed diagnostic wind flow models for urban areas using the Röckle approach, which initializes the system by parameterizing simple vortex structures behind and around buildings. The three-dimensional wind flow is then solved for based on mass-consistency constraints. This paper describes a comparison exercise with four of these Röckle-based urban wind flow models, using field data collected during the Joint Urban 2003 (JU2003) study in Oklahoma City, OK. The four models were developed by the Israel Institute for Biological Research, by the U.S. Los Alamos National Laboratory, by the U.S. Defense Threat Reduction Agency, and by the U.S. Army Research Laboratory. A variety of meteorological measurements collected during two Intensive Operational Periods (IOPs 02 and 08) and a three-dimensional urban building database are used as input to the Röckle-based models. Common geographic domain boundaries and assumed upwind inflow wind profiles have been agreed upon. The predictions of the Röckle-based wind fields are analyzed, compared, and discussed.

Future plans call for the building scale wind flow solutions generated by the models to be used as input to the Atmospheric Transport and Dispersion (AT&D) models developed by the four groups and linked with the wind flow model outputs. Concentrations of sulfur hexafluoride (SF6) predicted by the AT&D models will be compared to actual SF6 measurements during JU2003 IOPs 02 & 08 at multiple vertical levels and at various time intervals over the experimental domain.