Physical Oceanography, Vol.
THERMOHYDRODYNAMICS OF THE OCEAN
INVESTIGATION OF THE FIELDS OF CONCENTRATION OF THE SUSPENSION
ON THE NORTHWEST SHELF OF THE BLACK SEA IN THE CASE OF ROILING
OF THE BOTTOM SEDIMENTS BY A MOVING CYCLONE
D. V. Alekseev,
V. A. Ivanov,
E. V. Ivancha,
V. V. Fomin,
and L. V. Cherkesov
The processes of roiling of the bottom sediments, diffusion transport of the suspension, and its
repeated sedimentation on the northwest shelf of the Black Sea caused by a moving cyclone are
studied by using a numerical sigma-coordinate model. It is supposed that bottom sediments are
formed by particles of the same type. We determine the regions of the most intense rise of the
suspension, directions of its transport by the flows of water, and the vertical profiles of concen-
tration of suspended bottom sediments in different regions. In particular, it is shown that the dis-
tribution of suspended substances at a distance of
from the bottom reflects the location of the
active and inactive centers of erosion.
The northwest shelf of the Black Sea suffers significant anthropogenic loads. Pollutants appear in this regi-
on with river discharge, industrial wastes, precipitation, and as a result of technogenic accidents in the water area
of the sea. One of the main mechanisms of self-cleaning of water ecosystems is connected with the transition of
detrimental impurities from the water medium into the bottom sediments [1, 2]. Thus, heavy substances directly
participate in the gravitational sedimentation, whereas light substances are first adsorbed by the particles of min-
eral or organic suspensions. At the same time, bottom sediments can also play the role of a source of repeated
pollution of marine media. Thus, in shallow-water regions with intense dynamics of waters formed, in particu-
lar, under the influence of cyclonic-type atmospheric anomalies [3, 4], the action of bottom shear stresses leads
to the roiling of sediments. As a result, the pollutants return into the suspended state.
The problem of erosion of bottom sediments by mesoscale cyclonic and anticyclonic eddies and meander-
ing longshore and tidal currents is studied in [5–7]. Moreover, it is of interest to determine the locations of the
regions of rise of the suspension, the directions of its transfer, and the vertical distribution of suspended sub-
stances in the case where the dynamics of waters is formed under the influence of a moving cyclone. In the pre-
sent work, these investigations are carried out for the northwest shelf of the Black Sea on the basis of the numer-
ical sigma-coordinate hydrodynamic model  adapted to the regional conditions. In specifying the erosion and
sedimentation flows, we use the approximation which proved to be quite efficient for the simulation of turbidity
in the estuaries [7, 9].
Marine Hydrophysical Institute, Ukrainian Academy of Sciences, Sevastopol.
Marine Department of the Ukrainian Scientific-Research Hydrometeorological Institute, Sevastopol.
Translated from Morskoi Gidrofizicheskii Zhurnal, No.
3–20, January–February, 2007. Original article submitted July 12, 2005;
revision submitted September 23, 2005
0928-5105/07/1701–0001 © 2007 Springer Science+Business Media, Inc. 1