An evaluation of Aermod's performance in an urban dispersion environment

A new advanced dispersion model, AERMOD, has been subjected by the United States Environmental Protection Agency (EPA) to a rigorous set of performance evaluations involving 17 databases to ensure that the model's predictions are reasonably unbiased. Of these databases, only one involved an urban area. This thesis work significantly expands the urban evaluation of AERMOD.; Several urban field experiments were reviewed, and two were selected for this investigation: one involved summertime near-surface non-buoyant releases in Oklahoma City while the other involved wintertime elevated buoyant releases in Minneapolis.; The evaluation was conducted using two basic model configurations identified in the AERMOD Implementation Guide for urban applications. The model predictions were compared with each other and to the measured concentrations. The results have provided additional information on the accuracy and bias of AERMOD's urban model formulation and lead to recommendations for further research and possible changes to AERMOD's urban formulation.