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 s pecies and anthropogenic aerosols at various scales of atmospheric motions in urban and regional scales. The model employs flexible horizontal grid re solution with multiple multi-level nested grids with options for one-way an d two-way nesting procedures in a spherical and terrain-following coordinat e. The NAQPMS is driven using meteorological fields from the NCAR/Penn Stat e Fifth-Generation Mesoscale Model (MM5). Hourly pollutant levels of 71 sta tions covering Taiwan are used to evaluate the modeling system. Case simula tion of a high-ozone episode occurred during April 13-15 1999 shows that th e technique of the model nesting is capable of affording more realistic tem poral and spatial structures of concentration fields, processes and precurs ors.