Physical Oceanography, Vol. 19, No. 3, 2009
THERMOHYDRODYNAMICS OF THE OCEAN
GENERATION OF SURFACE AND INTERNAL WAVES IN A BOUNDED BASIN
BY A MOVING BARIC FRONT
S. F. Dotsenko and N. A. Miklashevskaya
We consider a plane problem of generation of surface and internal waves in a bounded rotating
basin of variable depth by a front of atmospheric pressure moving over the basin. The fluid is
assumed to be two-layer. The system of nonlinear long-wave equations is solved numerically by
the method of finite differences for the distribution of depths corresponding to a zonal section of
the Black-Sea basin. It is shown that the baric front moving over the basin generates barotropic
and baroclinic oscillations of the fluid. The intensity of disturbances depends on the velocity of
motion and the width of the front. There exists a velocity of motion of the front for which inter-
nal waves are generated especially efficiently. When the front leaves the basin, we observe the
formation of a packet of internal waves propagating from one lateral boundary of the basin to the
other boundary with reflections from the boundaries.
Seiches are free standing waves in closed or semiclosed basins [1–3]. They can be induced by various ex-
ternal actions including  the nonuniform distributions of atmospheric pressure over the basin and their time
evolution, the action of wind stresses on the surface of the basin, sharp elevations or lowerings of the level of
fluid in some parts of the basin due to the inflow or outflow of waters and/or precipitation in the form rain or
hail, seismotectonic displacements of the bottom if the zone of deformations of Earth’s crust covers a part of the
bottom , and internal waves, in particular tidal, reflecting from the edge of the shelf .
Seiches introduce significant contribution to the variations of hydrodynamic fields and act for long periods
of time reaching
of the iceless period, e.g., in Lakes Baikal and Balkhash . The seiche oscillations
are always accompanied by currents whose measurement enables us to identify seiches and study their properties
as, e.g., in [4, 7]. Seiches affect the transfer of substances, the process of mixing in marine media, and the redis-
tribution of chemical and biological substances. In this case, a significant role is played by the stratification of
density. Hence, the theoretical and experimental studies of seiches in lakes, fiords, and sea or oceanic basins
with regard for the baroclinicity of the medium form an important direction of contemporary oceanological in-
The horizontal structure and the parameters of long internal waves in closed basins (baroclinic seiches) de-
pend on the geometry of the basin and its density (temperature) stratification. Although the first theoretical and
experimental investigation of the structure of internal seiches and currents connected with seiches in lakes was
carried out about
ago , the internal seiches are now studied much less completely than the barotropic
seiches. In numerous theoretical works, the analysis of baroclinic seiches was performed within the framework
of two-layer or, sometimes, three-layer models of marine media. A survey of the results of investigation of in-
ternal seiches can be found in .
Marine Hydrophysical Institute, Ukrainian Academy of Sciences, Sevastopol, Ukraine.
Translated from Morskoi Gidrofizicheskii Zhurnal, No.
3–18, May–June, 2009. Original article submitted February 20, 2008.
0928-5105/09/1903–0125 © 2009 Springer Science+Business Media, Inc. 125