Fig. 8.

Comparing normalized concentration (χ) between AERMOD model results and wind tunnel observations. Shown are the No Barrier case (0 m), and Barrier cases with a barrier located at either the upwind edge (Upwind) or downwind edge (Downwind) of the roadway and with a barrier height of either 4.5 m or 6 m. Concentration values are shown as dots with red dots for locations from ground level (z/H = 0) to 6 m (z/H = 1). Dashed lines signify the FAC2 for concentration values. The geometric mean (MG) and geometric standard deviation (SG) statistics are shown for each case and are calculated with all data points (black) and also for the subset of ground-level to 6-m data points (red)