Metphomod - a numerical mesoscale model for simulation of regional photosmog in complex terrain: Model description and application during POLLUMET 1993 (Switzerland)

A prognostic three-dimensional Eulerian model for the simulation of summer smog was implemented which fully couples meteorological processes and gas phase chemistry. The model includes modules for atmospheric dynamics, atmospheric turbulence, transport, gas-phase chemistry, short- and long-wave radiation transfer, and surface interactions, including emission and deposition of trace gases. The model was tested in a numerical study of 29-30 July 1993 on the Swiss Plateau and compared to the data of the POLLUMET measurement campaign. Model results were found to be in good agreement with measurements. The model revealed a complex interaction of long range transport, dispersion of plumes from urban areas, and local influences of the complex Swiss topography on local wind systems, and local ozone concentration maxima during that episode.