Turbulence dissipation rate derivation for meandering occurrences in a stable planetary boundary layer G. A. Degrazia1, A. Goulart2, J. Costa Carvalho3, C. R. P. Szinvelski1, L. Buligon1, and A. Ucker Timm1 1Departamento de Física, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil 2Centro de Tecnologia de Alegrete, UNIPAMPA/UFSM, Alegrete, RS, Brazil 3Faculdade de Meteorologia, Universidade Federal de Pelotas, Pelotas, RS, Brazil
Abstract. A new formulation for the turbulence dissipation rate ε
occurring in meandering conditions has been presented. The derivation
consists of a MacLaurin series expansion of a lateral dispersion parameter
that represents cases in which turbulence and oscillatory movements
associated to the meandering events coexist. The new formulation presents
the identical physical premises contained in the classical and largely used
one, but the new formulation derived from meandering situations is expressed
in terms of the loop parameter m that controls the absolute value of the
negative lobe in the meandering autocorrelation function. Therefore, the m
magnitude regulates the turbulence dissipation rate. This dissipation rate
decreases for cases in which turbulence and low frequency horizontal wind
oscillations coexist and increases for a fully developed turbulence.
Furthermore, a statistical comparison to observed concentration data shows
that the alternative relation for the turbulent dissipation rate occurring
in situations of meandering enhanced dispersion is suitable for applications
in Lagrangian Stochastic dispersion models.
Citation: Degrazia, G. A., Goulart, A., Costa Carvalho, J., Szinvelski, C. R. P., Buligon, L., and Ucker Timm, A.: Turbulence dissipation rate derivation for meandering occurrences in a stable planetary boundary layer, Atmos. Chem. Phys., 8, 1713-1721, doi:10.5194/acp-8-1713-2008, 2008.