Turbulence dissipation rate derivation for meandering occurrences in a stable planetary boundary layer

[摘要] A new formulation for the turbulence dissipation rate εoccurring in meandering conditions has been presented. The derivationconsists of a MacLaurin series expansion of a lateral dispersion parameterthat represents cases in which turbulence and oscillatory movementsassociated to the meandering events coexist. The new formulation presentsthe identical physical premises contained in the classical and largely usedone, but the new formulation derived from meandering situations is expressedin terms of the loop parameter m that controls the absolute value of thenegative lobe in the meandering autocorrelation function. Therefore, the mmagnitude regulates the turbulence dissipation rate. This dissipation ratedecreases for cases in which turbulence and low frequency horizontal windoscillations coexist and increases for a fully developed turbulence.Furthermore, a statistical comparison to observed concentration data showsthat the alternative relation for the turbulent dissipation rate occurringin situations of meandering enhanced dispersion is suitable for applicationsin Lagrangian Stochastic dispersion models.

[学科分类] 大气科学