Two-point correlation statistics in the atmospheric surface layer

Abstract

A collaborative experimental effort in the western Utah salt flats [7] has enabled us to map coherence in turbulent boundary layers at very high Reynolds numbers [Re τ ≈ O(10 6)]. It is found that the large-scale coherence recently noted in the logarithmic region of laboratory-scale boundary layers [4] is also present in the very high Reynolds number atmospheric surface layer [5]. Two-point correlation for the streamwise fluctuation is compared for the stable, neutral and unstable surface layers in a plane parallel to the surface. The observed differences in the spatial features of the correlation maps can be characterized by the stability parameter z/ζ. Further, the integral length scales o..