A nested air quality prediction modeling system for urban and regional scales: Application for high-ozone episode in Taiwan

A nested air quality prediction modeling system (NAQPMS) has been developed to investigate the various processes that govern the loading of chemical species and anthropogenic aerosols at various scales of atmospheric motions in urban and regional scales. The model employs flexible horizontal grid resolution with multiple multi-level nested grids with options for one-way and two-way nesting procedures in a spherical and terrain-following coordinate. The NAQPMS is driven using meteorological fields from the NCAR/Penn State Fifth-Generation Mesoscale Model (MM5). Hourly pollutant levels of 71 stations covering Taiwan are used to evaluate the modeling system. Case simulation of a high-ozone episode occurred during April 13-15 1999 shows that the technique of the model nesting is capable of affording more realistic temporal and spatial structures of concentration fields, processes and precursors.