A semi-empirical method to compute concentrations associated with surface releases in the stable boundary layer

Abstract We present a semi-empirical method to estimate ground-level concentrations associated with near surface releases in the stable boundary layer. Our expression for the cross-wind integrated concentration C y which was derived from the Prairie Grass data (Barad, 1958) is C = x −1 ; x ⩽ 1.4 C = 0.89 x − 2 3 ; x > 1.4 , where C = C y u ∗ L Q ; x = x L and Q is the emission rate, u ∗ is the surface friction velocity, L is the Monin-Obukhov length, and x is the distance from the release. As both u ∗ and L can be related to the wind speed (Venkatram, 1980) the formulation for C y is suitable for routine dispersion estimates.