Simulation of the Circulation and Space Structure of Thermohaline Fields in the Sevastopol Bay with Regard for the Actual External Data (Winter, 1997)

Abstract

551.465We discuss the results of the numerical experiment aimed at the simulation of the behavior of currents and transformations of the temperature and salt modes in the Sevastopol Bay in January-February 1997. In the numerical analysis, we use actual data on the velocity and direction of the wind, sea surface temperature, and the discharge of River Chernaya. It is shown that the circulation and structure of hydrological fields are mainly connected with the direction of the wind, its intensity, and variability in the course of time. Since the analyzed water area is shallow, the currents inside the bay undergo rapid transformations (less than for an hour after changes in the wind). At the same time, the transformations of the thermohaline fields are slower. Due to the inflow of fresh waters of River Chernaya and salt waters from the open sea through the strait, the structure of thermohaline fields formed in the bay is nonuniform (both in the vertical and horizontal directions). The distribution of salinity plays the main role in the formation of the vertical stratification, which is natural for the winter season. Due to the process of freshening of water, a quite high vertical salinity gradient is formed in the upper layer of the sea. As a result, the process of cooling does not lead to the appearance of convection and inversions of temperature are formed in the case where warmer waters are located in the bottom layers.In recent years, the results obtained with the help of mathematical models of the ecological state of various coastal water areas are extensively and successfully applied for the efficient solution of the problems of ecological safety in these areas. The Sevastopol Bay is one of important regions of great scientific interest. As the principal factors specifying the natural properties of waters in the Sevastopol Bay, one can mention the interaction with the atmosphere (heat exchange, precipitation, and evaporation), freshening by the waters of River Chernaya flowing into the east part of the bay and waste waters, and the interaction with waters of the open sea through the strait in the west part of the bay including, in particular, the process of salinization with seawater coming into the bay. The interaction of waters coming into the bay and their mixing as a result of advection and turbulent diffusion lead to the formation of transformed waters specific for the bay. The properties of these waters and the level of anthropogenic influence vary depending on the ratios of the volumes of fresh (river and waste waters and precipitation) and salt (sea) waters coming into the bay. The dynamics and transformations of these waters should be studied within the framework of a model of the ecosystem of the bay whose thermohydrodynamic block must describe the circulation and thermohaline structure of waters in the analyzed region. In [1], the circulation of waters is described by using the Fel'zenbaum model [2], i.e., a barotropic linear model of steady wind currents in a homogeneous sea neglecting the horizont...

Intra-Decadal (2012–2021) Dynamics of Spatial Ichthyoplankton Distribution in Sevastopol Bay (Black Sea) Affected by Hydrometeorological Factors

“…The interannual variability of the ichthyoplankton abundance in different areas of the Sevastopol Bay and its determining factors had been studied very fragmentally [ 3 , 4 , 5 , 6 , 7 , 8 , 9 ]. At the same time, significant data on the hydrodynamic and hydrochemical regimes of the bay have been collected [ 10 , 11 , 12 , 13 , 14 , 15 ]. Some previous works investigated the causes of pollution and their spatial distribution over the water area of the Sevastopol Bay [ 13 , 16 ].…”

Investigation of Seiche Oscillations in the Adjacent Bays by the Example of the Sevastopol and the Quarantine Bays

“…In [4], a numerical calculation of the eigen modes of the Sevastopol Bay was carried out. Based on mathematical modeling the currents in this bay were studied in [5] and the dynamics of the contaminating impurity spread -in [6]. There are no observational data on hydrophysical parameters for the Quarantine Bay.…”

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“…Studies of hydrologic-hydrochemical and hydrodynamic characteristics of the Sevastopol Bay were carried out earlier on the basis of both field observations [1,2] and the results of mathematical modeling [3,4]. The increased volume of environmental information and modern interdisciplinary mathematical models provided more accurate predictions of the state and dynamics of marine coastal waters [5][6][7][8][9], including for the Black Sea *.…”