Laboratory simulation of coriolis effects on atmospheric dispersion of airborne tracers over a complex terrain

The experimental research described here deals with a problem of diffusion and transport on local scale (30 km) of pollutants of urban and industrial origin, emitted into the atmosphere of a complex terrain site, with noticeable orographical features. The diffusion process was visualized and analysed in detail. The results of this research allowed acquiring the capability of forecasting environmental impact on the area, due to the sources considered. On account of its spatial scale, the phenomenon was investigated in a rotating hydraulic channel, by the method of simulation on physical model at reduced scale. Typical local atmospheric conditions, taking into account diurnal evolution of stability inside a turbulent, rotating planetary boundary layer, were modeled. Seasonal variations of sources emission rates were considered. Measurements of dilution factors at several spatial points of the model and at five levels (from ground up to a height equivalent to about 1000m) allowed mapping out concentration isolines over the site in various conditions and producing evolving contour plots which visualized the diffusion processes in a very useful way for planning purposes.