Wind speed and thermal gradient in a moderately stable PBL

In the inertial layer of a moderately stable BL ( 0 < Ri < 0.2) the M.O. similarity theory gives the profiles of wind speed U and thermal gradient Δθ as functions of the dimensionless height ζ = z/L. Experimental works permit to evaluate ζ and the similarity functions Ψm and Ψh from Ri. Giving the correct values for z0 and u if Δθ known it is possible to calculate U(z) at any z contained in the inertial layer. This relationship is used to explain the clustering of values of U and ΔT/Δz measured at two stacks of a TWA power plant