Improvement of the vertical mixing in chemistry transport modeling based on a 1.5-order turbulence kinetic energy-based eddy diffusivity closure scheme

In this study, firstly, three first-order local closure vertical diffusion schemes used in multiple mesoscale chemical transport models (CTM) were embedded the CHIMERE CTM model and tested over a one-year simulation covering whole France. Three configurations present fair reproduction of pollutant concentrations both urban rural areas, indicating it is an effective way to reproduce dispersion pollutants chemistry modeling. However, cannot be expected significantly improve mixing under scheme. Secondly, 1.5-order turbulence kinetic energy-based eddy diffusivity scheme called as new (NED) implemented describe more realistic processes near surface. A fifteen-day encompassing winter pollution episode was performed for major cities with horizontal resolution 1.67 km first layer height at 12 m, respectively. The NED improved NO2 simulations most sites compared initial Kz (IKD). Taking root mean square error evaluation criteria, average improvements are 18.8%, 24.5% 9.5% simualtion Paris, Lyon Bordeaux For performance PM2.5 PM10 areas 13.5% 19.1%, Overall, preliminary outcomes study encouraging. sophisticated viscosities better than IKD that widely CTMs, but we need realize only cities, further research, longer periods needed greater variety meteorological situations prove universality