Modeling of Turbulent Patches Statistical Distribution in the Stratified Ocean Layers

A. M. Chukharev1, ✉, K. V. Runovsky2, O. E. Kulsha2

1 Marine Hydrophysical Institute, Russian Academy of Sciences, Sevastopol, Russian Federation

2 Branch of the M.V. Lomonosov Moscow State University in Sevastopol, Russian Federation

✉ e-mail: alexchukh@mail.ru

Abstract

Model for the spectrum of density pulsations in a stratified layer of fluid is proposed. It assumes presence of the mechanism vertical turbulent exchange resulting from breaking of the internal waves and formation of the turbulent patches. The mechanism is considered to be quite widespread in many regions of the World Ocean. Modeling implies consideration of two sources of fluctuations: internal waves existing in the whole layer and turbulence concentrated within a certain number of patches distributed within the layer under consideration. The scale ranges of the internal waves and turbulence are partially overlapped; at that the maximum scale of turbulent pulsations is limited by a patch size. Basing on the theory of locally isotropic turbulence and assuming that the oscillations inside a patch are described by harmonic functions, it is shown that their local frequency and local amplitude are connected by the analytical relationship. In the model functions, both the amplitude and the phase of oscillations are randomized, white noise is added to them. The major features of influence of various specified characteristics of the patches and internal waves upon the spectrum shape are determined. The experimental data have being analyzed by means of the proposed model permit to evaluate the scales and amount of the patches, as well as their turbulence energy level. The model also exhibits validity of the earlier developed energy approach for defining the scales of turbulent patches.

Keywords

stratified layer, vertical exchange, internal waves, microstructure, spectral model, turbulent patch

For citation

Chukharev, A.M., Runovsky, K.V. and Kulsha, O.E., 2017. Modeling of Turbulent Patches Statistical Distribution in the Stratified Ocean Layers. Physical Oceanography, (5), pp. 31-41. doi:10.22449/1573-160X-2017-5-31-41

DOI

10.22449/1573-160X-2017-5-31-41

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