AERMOD Tech Guide

Gaussian Plume Air Dispersion Model

8.12 Using Measured Mixing Heights

If measured mixing heights are available, then they are treated in the following manner: If L>0 (SBL) the measured mixing height is defined as zie and it is treated the same as a calculated mechanical mixing height (smoothing, etc). If L<0 (CBL) the measured mixing height is defined as zic , and zie is calculated from eq. (12) then proceed as if both zic and zim had been calculated values.

If a user has “measured” mixing heights available (and chooses to use them), the model defaults to substituting calculated mixing heights for missing measurements and a message is written that a substitution has occurred. If the user elects to substitute calculations for missing measurements, the model will print out a message to the message file for each hour that a substitution has occurred.