Physical Oceanography, Vol. 19, No. 5, 2009
LABORATORY MODELING OF THE PROPAGATION OF PERIODIC INTERNAL
WAVES OVER BOTTOM SLOPES
S. F. Dotsenko
and N. K. Shelkovnikov
The experimental investigation of the run-up of periodic internal waves in a two-layer fluid on
the coastal slope is performed in an open hydrochannel at the Physical Department of the Lomo-
nosov Moscow State University. The waves are produced by a wave generator. We study the
transformation of waves, the vertical structure of the field of velocities of mass transfer, and the
behavior of the parameters of internal waves propagating over the sloping bottom. It is shown
that the run-up and breaking of internal waves are accompanied by periodic emissions of portions
of the heavier fluid from the bottom layer upward along the slope. The Stokes drift velocity
changes its sign as a function of depth. Moreover, both the wave length (the horizontal distance
between the neighboring crests) and the height of waves over the sloping bottom (the elevation
of the crest over the slope along the vertical) decrease as the wave approaches the coast.
In the process of propagation of internal waves in the ocean, they are transformed and, hence, their space-
and-time characteristics undergo certain changes. In numerous cases, this is caused by the changes in the depth
of the basin, mean currents, and density field, by reflections from the underwater slopes and coasts, by disper-
sion, and by the nonlinear interaction of waves.
In what follows, we present the results of laboratory investigations of the two-dimensional problem of pro-
pagation of periodic internal waves in a basin filled with a two-layer fluid from the region of constant depth to
the shallow-water coastal zone with plane sloping bottom. The specific features of the processes of propagation
and breaking of internal waves over the sloping parts of the bottom in two-layer fluids and fluids continuously
stratified along the vertical were studied on the basis of the data of in-situ observations  by the methods of
laboratory [2–4] and numerical [5–7] simulation. A survey of investigations of internal waves including the dis-
cussion of the analyzed problem can be found in . The attention of the researchers to the investigation of the
evolution and breaking of internal waves under the indicated conditions is explained by their significant contri-
bution to the dynamics of the ocean over the underwater slopes and mountains, to the morphodynamics of the
bottom in the zones of intense baroclinic motions, and to the intensification of vertical exchange in the ocean.
Laboratory Installation and the Method of Investigation
The experimental investigation of the transformations of periodic internal waves in a two-layer fluid run-
ning up over the plane coastal slope is performed in a special laboratory installation at the Physical Department
of the Lomonosov Moscow State University. The schematic diagram of this installation is presented in Fig.
Marine Hydrophysical Institute, Ukrainian Academy of Sciences, Sevastopol, Ukraine.
Lomonosov Moscow State University, Moscow, Russia.
Translated from Morskoi Gidrofizicheskii Zhurnal, No.
37–46, September–October, 2009. Original article submitted May 29,
0928-5105/09/1905–0301 © 2009 Springer Science+Business Media, Inc. 301