AERMOD Tech Guide
3.1.3 Convective Mixing Height(z)
If measurements of the convective boundary layer height (zic ) are available they are selected and used by the model. If measurements are not available, zic is calculated with a simple one- dimensional energy balance model (Carson, 1973) as modified by Weil and Brower (1983). This model uses the early morning potential temperature sounding (prior to sunrise), and the time varying surface heat flux to calculate the time evolution of the convective boundary layer as
Weil and Brower found good agreement between predictions and observations of z ic, using this approach.