Pasquill-Gifford dispersion parameters

As an example of the use of the Gaussian plume equations using the Pasquill-Gifford dispersion parameters, assume that a source releases 0.37 g s of a pollutant at an effective height of 40 m into the atmosphere with the wind blowing at 2 m s . What is the approximate distance of the maximum concentration, and what is the concentration at this point if the atmosphere is appropriately represented by Pasquill stability class B ... 

The Pasquill-Gifford dispersion parameters and Brigg s plume rise equations. 

The Pasquill-Gifford dispersion parameters are functions of downwind distance and meteorological conditions. The parameters, and Oy may be obtained from Figure 6(a) and 6(b) respectively. The user must know the atmospheric stabihty as well as downwind distance from the somce to select the appropriate dispersion parameters... 

A power plant burns 10 kg h of coal containing 2.5% sulfur. The effluent is released from a single stack of height 70 m. The plume rise is normally about 30 m, so that the effective height of emission is 100 m. The wind on the day of interest, which is a sunny summer day, is blowing at 4 m s . There is no inversion layer. Use the Pasquill-Gifford dispersion parameters from Table 18.2. 

Pasquill s dispersion parameters were restated in terms of a-y and Cj by Gifford (14, 15) to allow their use in the Gaussian plume equations. The... 

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