Physical Oceanography, Vol.
12, No. 4, 2002
THERMOHYDRODYNAMICS OF THE OCEAN
EVOLUTION OF THE COLD INTERMEDIATE LAYER IN THE BLACK SEA
ACCORDING TO THE RESULTS OF ASSIMILATION OF CLIMATIC DATA
IN THE MODEL
S. G. Demyshev, G. K. Korotaev, and V. V. Knysh
We present the results of analysis of the seasonal variability of the “climatic” cold intermediate
layer based on a complex approach with the use of series of successive changes in the hydro-
physical parameters computed according to the model with assimilation of the climatic fields of
temperature and salinity. We analyze some mechanisms of formation of the cold intermediate
layer. It is discovered that the layer of cold waters, which is continuous after regeneration and
transformation in the entire deep-water area of the sea, becomes discontinuous at the end of the
year (October–November). One of the possible mechanisms responsible for the appearance of
discontinuities is discussed.
The most remarkable feature of the vertical thermohaline structure of Black Sea waters is the presence of a
cold intermediate layer with water temperature of
located at depths of
The space and time variability and some aspects of the formation of the cold intermediate layer were stu-
died, on the basis of the analysis of the monthly average climatic fields of temperature and salinity [1, 2] in [3,
4]. Some mechanisms of formation of the cold intermediate layer in local regions of the Black Sea were studied
in [5–8] using the data of hydrophysical surveys and sections.
It should be emphasized that the monthly climatic arrays of temperature and salinity [1, 2] have numerous
disadvantages, including the presence of “noises,” poor availability of data from some regions of the sea, dis-
agreement between different fields and between the fields and physical and geographic characteristics of the
basin, and the presence of measurement errors.
In the present work, the seasonal variability of the “climatic” cold intermediate layer is analyzed on the ba-
sis of a complex approach with the use of the series of successive changes in the climatic hydrophysical parame-
ters. We dwell upon some mechanisms of formation of the cold intermediate layer and the specific features of
its structure in different periods of its annual variation.
As a method of analysis, we use the procedure proposed in  for the reconstruction of the continuous (in
time) seasonal variation of the climatic parameters of the Black Sea on the basis of successive assimilation of the
climatic distributions of temperature and salinity in the numerical model. In the same work, the results of analy-
sis of the annual variation of the sea-level fields and the horizontal and vertical current velocities are presented
It is shown that the layer of cold waters, which is continuous (after regeneration and transformation) in the
entire deep-sea area of the basin, becomes discontinuous at the end of the year (October–November). We study
one of the possible mechanisms responsible for the formation of discontinuities in the cold intermediate layer.
Marine Hydrophysical Institute, Ukrainian Academy of Sciences, Sevastopol. Translated from Morskoi Gidrofizicheskii Zhurnal,
3–19, July–August, 2002. Original article submitted April 17, 2001.
0928-5105/02/1204–0173 $27.00 © 2002 Plenum Publishing Corporation 173