Physical Oceanography, Vol. 15, No. 3, 2005
LONG-TERM VARIATIONS OF THE THERMOHALINE AND DYNAMIC
CHARACTERISTICS OF THE BLACK SEA ACCORDING TO THE
CLIMATIC DATA ON TEMPERATURE AND SALINITY
AND THEIR ASSIMILATION IN THE MODEL
V. V. Knysh, G. K. Korotaev, S. G. Demyshev, and V. N. Belokopytov
We compare the thermohaline and dynamic characteristics of the Black Sea reconstructed by us-
ing two versions of climatic temperature and salinity fields: old (1903–1982) and new (1903–
2003). The fields are reconstructed with the help of continuous assimilation of the climatic tem-
perature and salinity in the model. It is shown that the climatic thermohaline fields constructed
with regard for the data of observations for the last
are characterized by an insignificant
elevation of the halocline (pycnocline) in the winter–spring period and the elevation of the upper
boundary of the cold intermediate layer in the spring–summer period. The intensity of surface
geostrophic currents is greater than the same quantity computed on the basis of the old climatic
data for the whole year. The horizontal currents in the sea computed according to the new clima-
tic data are more intense.
Long-term variations of the thermohaline structure and dynamic characteristics of Black-Sea waters deter-
mined by the many-year nonstationary behavior of external factors draw permanently increasing attention of the
researchers. This is explained by the necessity of solution of the problems of regional oceanography based on
the knowledge of the variations of sea climate and the increasing influence of external anthropogenic factors.
The analysis of the processes of long-term transformation of the structures of hydrophysical parameters of
the sea is a fairly complicated problem, which requires long series of observations (not only in local but also in
various parts of the investigated basin). However, the required data of observations are available only for some
points of the sea and, thus, cannot serve as a basis for making conclusions concerning the trends in the behavior
of geophysical parameters typical of the entire basin.
It seems likely that the existing data of many-year observations of temperature and salinity can be used for
the analysis of long-period variations of the structure of waters in the Black Sea. It is a priori clear that the cli-
matic arrays of these parameters obtained by various methods for long but different periods of time contain valu-
able information on the character of long-term trends in the behavior of thermohaline and dynamic characteris-
tics of the sea. The principal problem encountered in this case is how to reveal the specific features of these
There are numerous works devoted to the investigation of the variability of the thermohaline structure of
waters in the Black Sea with time. These works mainly deal with the analysis of the response of salinity and
temperature fields to changes in the river discharge [1–5]. We can also mention the works [6, 7] where the re-
sults of these investigations are generalized most completely. However, the systematic description of many-year
variability of the hydrophysical characteristics is absent up to now.
In the present work, we compare the thermohaline and dynamic characteristics of the Black Sea recon-
structed on the basis of two versions of climatic temperature and salinity fields [8, 9]. The reconstruction of
Marine Hydrophysical Institute, Ukrainian Academy of Sciences, Sevastopol.
Translated from Morskoi Gidrofizicheskii Zhurnal, No.
11–30, May–June, 2005. Original article submitted February 4, 2004.
142 0928-5105/05/1503–0142 © 2005 Springer Science+Business Media, Inc.