Physical Oceanography, Vol. 17, No. 4, 2007
THERMOHYDRODYNAMICS OF THE OCEAN
NUMERICAL SIMULATION OF CURRENTS IN A BASIN OF VARIABLE DEPTH
WITH TWO STRAITS
S. G. Demyshev, O. A. Dymova, and L. V. Cherkesov
Within the framework of the linear theory of long waves, with regard for the turbulent viscosity,
we study the development of tidal currents in a basin of variable depth with two straits. The
problem is solved numerically. The velocity field on the strait–basin boundary is regarded as
known. The numerical analysis is performed for different depths of the straits. We study the in-
fluence of the geometric characteristics of the basin on the amplitudes of the profile of free sur-
face and wave velocity and establish the dependences of the wave characteristics on the period of
current velocities in the strait and the parameters of the basin. In particular, it is shown that the
increase in the period of current velocities in the strait leads to significant changes in the level
and structure of currents.
The hydrological characteristics of the Black Sea noticeably depend on the water exchange through Bospo-
rus. The inflow of saltier waters saturated with oxygen from the Sea of Marmara makes a significant contribu-
tion to the stability of the Black-Sea ecosystem.
The numerical simulation of currents in the sea based on the hydrodynamic models proves to be a powerful
tool of investigations. A box model of the dynamics of the so-called Turkish strait system (Dardanelles, Sea of
Marmara, and Bosporus) is proposed in . This model enables one to describe the most general features of cir-
culation in the upper layer of the Sea of Marmara. In , the process of formation of the three-dimensional hy-
drodynamic structure of waters in the Sea of Marmara with regard for the influence of the straits is studied by
using the complete nonlinear numerical model. Unlike the cited works, the application of the one-layer model
enables one to select and study basic physical mechanisms responsible for the formation of the specific features
of the dynamics of waters. This investigation was originated in , where we studied the development of tidal
currents in a basin of constant depth with regard for the action of dissipative forces.
In the present work, on the basis of a linear numerical model, we study the influence of the geometric par-
ameters of a basin of variable depth and the parameters of external flows through the straits on the structure of
currents. The chosen dimensions of the basin and the presence of two straits simulate the geometric characteris-
tics of the Sea of Marmara.
Statement of the Problem
Consider a rectangular basin of variable depth with sizes a and b and two straits (Fig.
Marine Hydrophysical Institute, Ukrainian Academy of Sciences, Sevastopol.
Translated from Morskoi Gidrofizicheskii Zhurnal, No.
3–12, July–August, 2007. Original article submitted January 16, 2006;
revision submitted February 9, 2006.
0928-5105/07/1704–0191 © 2007 Springer Science+Business Media, Inc. 191