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 Cn2 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 ζ˜ = (z1z2)1/2/L with factor of 2 accuracy in the ranges of −3 ≤ ζ˜ ≤ −0.015 and 0.02 ≤ ζ˜ ≤ 10, the stabilities most commonly encountered in the surface layer.