Physical Oceanography, Vol. 18, No. 5, 2008
RECONSTRUCTION OF THE SPACE AND TIME VARIABILITY OF
THERMOHALINE FIELDS IN THE SEVASTOPOL BAY
É. N. Mikhailova and N. B. Shapiro
The aim of the present work is to reconstruct the space and time variability of the three-dimen-
sional fields of currents, temperature, salinity, and density in the Sevastopol Bay under the influ-
ence of the actual external factors in 1999. For this purpose, we use a version of the numerical
multilayer model on the
σ-coordinates. A vast array of the data of observations accumulated as a
result of regular monitoring of the Sevastopol Bay contains, in particular, the data on the sea-sur-
face temperature measured with six-hour intervals (at the hydrometeorological station located
near the center of the bay) and almost monthly vertical profiles of temperature and salinity ob-
tained at seven hydrological stations. The comparison of the numerical results with the data of
observations enables us to conclude that, in general, the model fairly correctly describes the
space structure and rearrangements of the fields of temperature and salinity. Among the most
important distinctions, we can mention the fact that the fresh river water penetrating into the bay
is mixed with seawater faster than predicted by the model. We also discuss the causes of these
The aim of the present work is to reconstruct the seasonal and daily variability of the three-dimensional
fields of currents, temperature, salinity, and density in an estuary-type basin by analyzing, as an example, the
Sevastopol Bay. One side of the bay borders with the open sea. The fresh-water River Chernaya flows into bay
on the other side.
A vast array of the data of observations accumulated as a result of regular monitoring of the Sevastopol Bay
carried out in recent years [1–3] describes not only the action of external factors (speed and direction of the
wind, air temperature, relative humidity, discharge of the Chernaya River, etc.) but also the three-dimensional
temperature and salinity fields in the sea (monthly vertical profiles at seven stations).
The first attempt to reconstruct the variations of hydrological fields in the Sevastopol Bay under the influ-
ence of the actual external factors in 1997–1999 was made within the framework of the one-dimensional version
of the multilayer quasiisopycnic model used to compute the vertical profiles of temperature and salinity averaged
over the area of the bay . This model was prognostic, i.e., the data of observations of the parameters of the
sea were not assimilated in the analysis of hydrological fields. These data were used solely for the comparison
with the numerical results. As shown in , the results of calculations were in satisfactory agreement with the
temperature and salinity fields averaged over the water area of the bay.
The transition to the numerical analysis of the three-dimensional fields of temperature, salinity, and current
velocity revealed a series of fairly complicated problems caused by the specific features of quite intense pro-
cesses running in a relatively shallow nonclosed water area of the bay and, as became absolutely clear, by the in-
sufficient capabilities of the multilayer quasiisopycnic model. Despite the fact that the physical processes are, to
the maximum possible extent, taken into account in the model [5–8], it is, in fact, practically impossible to get
the quantitatively correct reconstruction of the actual fields in the Sevastopol Bay even by using the actual exter-
Marine Hydrophysical Institute, Ukrainian Academy of Sciences, Sevastopol, Ukraine.
Translated from Morskoi Gidrofizicheskii Zhurnal, No.
23–39, September–October, 2008. Original article submitted March 1,
revision submitted March 21, 2007.
0928-5105/08/1805–0255 © 2008 Springer Science+Business Media, Inc. 255