An experimental study of atmospheric turbulent flow has been made to probe self-similarity and deviation from self-similarity of turbulence. Special emphasis is made on asymmetry as an indicator of the deviation from self-similarity. The scaling exponents for positive and negative parts of the velocity increments have been obtained for several moment orders, up to the sixth. The exponents do show asymmetry, predicted by the so-called ramp-model [S. I. Vainshtein and K. R. Sreenivasan, Phys. Rev. Lett. 73, 3085 (1994)]. This asymmetry, however, can be estimated as moderate. Much more pronounced asymmetry is found in the tails of the velocity increments probability distribution function (PDF’s). In particular, the odd moments are mainly defined by the asymmetry of the tails, rather than by that of the PDF core. The deviation from self-similarity is also quite pronounced for the joint two-point PDF.

• Received 2 July 1997

DOI:https://doi.org/10.1103/PhysRevE.56.6787