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 diurn al 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 ur ban site located in a complex area, with special focus on low wind conditio ns. 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 val ley. (C) 1999 Elsevier Science Ltd. All rights reserved.