Structure-Formation and Vertical Turbulent Exchange in the Coastal Area of the Sevastopol Region

With use of high-resolution probe-turbulimeter "Sigma-1" field data on the distribution of hydrophysical parameters in the upper layer of the sea around the Herakleian Peninsula (The Crimea) are collected. Based on the analysis of these data according to the previously developed methodology, the scales of turbulent patches in a stratified layer have been evaluated.On the basis of physic-climatic and hydrological conditions, it can be argued that the main source of turbulence here is the internal wave overturning which leads to the formation of turbulent spots. The coefficients of vertical turbulent exchange and the values of the dissipation rate of turbulent energy in the study area are calculated. Comparative analysis of data obtained in the spring and autumn seasons, showed different dependence of turbulent diffusion coefficients from the conditions of stratification. In the autumn, in the layers with small gradients of density coefficient is proportional to the buoyancy frequency, in the summer in the strongly stratified layer coefficient is already inversely proportional to this parameter. It is shown that the spatial distribution of diffusion coefficients reflects the characteristics of vertical exchange due to hydrologic structure and morphology of the bottom. The comparison of the results with our earlier "spectral" exchange model showed a good agreement of field measurements.