Experimental Study on the Diffusion of Air Pollutants in Urban Area
1994 Volume 29 Issue 3 Pages 113-122
Details
1994 Volume 29 Issue 3 Pages 113-122
In order to clarify the diffusion of air pollutants in Tokyo metropolitan area, where middle and high buildings are concentrated, air tracer (SF6) dispersion experiments were conducted at night time in winter. Two cases were under windy conditions and the other was under calm condition. Following conclusions were obtained through the analysis of these data:
(1) The highest concentration of the tracer gas in the vertical direction was not at the source height, but was at the height of a little higher than the average height of the middle-sized buildings.
(2) The advection direction of tracer clouds was consistent with the wind direction at 50 m height, which was a little higher than the average height of the middle-sized buildings, and the advectin velocity was 20-30% of the wind speed at 50 m height.
