Carbon monoxide modeling for urban air quality management

A unique approach to modeling volume averaged concentrations of non‐reactive urban pollutants is presented and applied to forecasting carbon monoxide concentrations. The non‐steady‐state box model determines concentrations averaged over a specified time period rather than concentrations at the end of the specified period as is characteristic of previous simplified models of this type. The model is evaluated by comparing concentrations with the volume averaged concentrations from a validated three‐dimensional state‐of‐the‐art advection‐diffusion‐transformation model over an entire spectrum of changes in the pollutant emission characteristics. Results are also compared with a steady‐state box model and with a standard linear rollback model to illustrate the differences in implementing a more sophisticated model for qualitative prediction. The non‐steady‐state box model is found to accurately and efficiently predict volume averaged carbon monoxide concentrations for both temporal and spatial emission alterations. Examples of how the model can be used by an urban air quality planner are discussed.