AERMOD Tech Guide

Gaussian Plume Air Dispersion Model

6.2.2 Indirect Source Contribution to Concentration Calculations in the CBL

The concentration contribution from the horizontal state of the indirect source is calculated as follow:

Equation (74)

The height of the indirect source rj is calculated from eq. (75). The total concentration for the terrain responding state has the form of eq.(74) with zr replaced by zp .

The dispersion coefficients (y ,z1 & z2 ) resulting from the total turbulence (ambient, buoyancy y z1 z2 induced & building induced) are calculated using eqs. (85) and (98) thru (103). The height of the indirect plume is given by the following expression:

Equation (75)

h is calculated from eq. (118). The aj’s in eq. (75) are calculated from eq. (72).