Turbulent Mixing Numerical Study in the Black Sea Basin Using Modified Version of the Pacanowski-Philander Formulation

In this paper, the Black Sea upper mixed layer (UML) structures in mid-February by using a 3-D numerical model of the Black Sea dynamics (BSM-IG, Tbilisi, Georgia) are investigated. In order to present the turbulent mixing peculiarities more clearly, a new version of the classical Pacanowski{Philander parameterization formulated by Bennis et al. (2010) for vertical turbulent viscosity and diffusion coefficients is integrated in the BSM-IG. The Black Sea UML homogeneity is estimated using criterion of temperature (?T = 0:2° C) and salinity (?S = 0:15 psu). Besides, mixed layer structures have been investigated according to both values of the Richardson number: RiT and RiS, respectively. As result analysis shows: in February UML structures in the temperature fields correspond to the Richardson number specificity, basically, but mixed layer homogeneity reduced in the salinity fields, when Richardson number changed in the following range 0:07 < RiS <= 1, especially, in deep waters of the sea basin.