Atmospheric stability from scintillation measurements

The Obukhov length L is an important meteorological parameter that quantifies the stability of the atmospheric surface layer. Consequently, routine monitoring of L with simple instruments is desirable. I describe here such a monitoring scheme, the SFS method, that has the added advantage of yielding a spatially averaged estimate of L. The SFS method—stability from scintillation—is based on measurements of the refractive-index structure parameter $C_n^2$ with two matched scintillometers positioned at heights z₁ and z₂. A sensitivity analysis shows that the method can yield an estimate of the stability parameter $\tilde{\zeta }$ = (z₁z₂)^1/2/L with factor of 2 accuracy in the ranges of −3 ≤ $\tilde{\zeta }$ ≤ −0.015 and 0.02 ≤ $\tilde{\zeta }$ ≤ 10, the stabilities most commonly encountered in the surface layer.