Comment on Local Similarity in the Stable Boundary Layer and Mixing-Length Approaches: Consistency of Conceptsby B. J. H. van de Wiel · A. F. Moene · W. H. De Ronde · H. J. J. Jonker, Boundary-Layer Meteorol (2008) 128: 103–116

The article’s calculation of the limitation of vertical displacements in stable stratification is based on a factor-of-two error in the potential-energy calculation. In consequence, the derived value of the numerical constant (slope) in the Monin–Obukhov (MO) similarity function, respectively in its local-scaling equivalent (Nieuwstadt), of 6.25 is reduced to 3.13. The low value is in agreement with several experimental results in the near-neutral range, but not for higher stability. MO theory, as well as local scaling, is based on continuous turbulence, and implies a linear similarity function in the entire stable branch. Therefore, it seems plausible to assume a stability-dependent systematic error in the experiments at larger stability that gives larger values for the slope.