A REDUCED-ORDER PHOTOCHEMICAL AIR QUALITY MODEL

We report on reduced-order photo-chemical model (TAPOM-Lite) designed for calculating ozone levels for varying urban scenarios and calibrated for the city of Geneva, Switzerland. The TAPOM-Lite model is an atmospheric-environmental model designed to be incorporated into a larger energy–economy–environment (E³) model and run in an optimization framework. The motivation for the TAPOM-Lite model was the design of a fast ozone calculator needed for the CPU-intensive optimization environment where many iterations are potentially required before a best solution is found. Three principal advances in this model are (1) a simplified chemical scheme for O₃ production, (2) linearization of the O₃ production function needed for the overseeing linear optimization program, and (3) the extraction of gradient (sensitivity) information calculated from the O₃ production function which in turn is needed as “directional” information in the optimization method. Results show that the TAPOM-Lite model is consistent with the full-scale TAPOM model throughout the optimization/iteration process. The TAPOM-Lite model provides a first coupled E³ program for optimization and also provides a framework for global application such as the linking of global indicators (e.g., mean temperatures) and world energy consumption.