The Black Sea Northern Part Spatial Zoning in Terms of the Mixing Processes Intensity Based on the Data Processing Results of 87, 92, 102 and 110 Voyages of the R/V “Professor Vodyanitsky”

The paper examines the results of expeditionary work carried out by the Turbulence department of the Marine Hydrophysical Institute of RAS in the Black Sea on the R/V Professor Vodyanitsky in various seasons of 2016–2019 in order to clarify the local and seasonal parts of the models of vertical turbulent exchange in the thermocline region. Graphs of seasonal variability in buoyancy frequency N and vertical turbulent exchange coefficient K were plotted. The study area was also divided into regions according to hydrological features and bottom topography, followed by a correlation analysis of the vertical turbulent diffusion coefficient variability with depth in each region. The dependencies profiles obtained, averaged over the selected regions, were compared with the 1.5D model and showed good convergence in the region of the seasonal and main thermoclines. The data covers the summer-autumn period and was collected using the Sigma-1 sounding complex. They include the shelf, slope and deep-water part of the economic zone of the Black Sea near the Crimean coast. The dependences K(N), K(z), N(z) were obtained based on existing semi-empirical models of vertical turbulent exchange. The estimates were based on an analysis of the spectra of vertical gradients of horizontal velocity pulsations. The spectra were calculated at three-meter depth intervals for each station, which at a signal sampling frequency of 100 Hz made it possible to obtain a reliable estimate. The main result of the work carried out is taking into account the characteristics of the selected regions in order to obtain in the future more accurate models of vertical turbulent exchange.