Thermal valley inversion impact on the dispersion of a passive pollutant in a complex mountainous area

This contribution deals with the large eddy simulations of a complete diurnal cycle of atmospheric flow within a schematic deep valley for two seasons (i.e. winter and summer). The scale of interest is characteristic of an urban site located in a complex area, with special focus on low wind conditions. The results of the numerical simulations describe the influence of the season on the mechanisms responsible for the formation and the destruction of the inversion layer, and its impact on pollutant trapping within the valley.