Physical Oceanography, Vol. 13, No. 4, 2003
CLIMATIC CHARACTERISTICS OF TEMPERATURE AND SALINITY FIELDS
IN DEEP-WATER LAYERS OF THE BLACK SEA
A. B. Polonskii and E. A. Lovenkova
UDC 551.465 (262.5)
The systematic and random errors of reconstruction of the climatic variability of temperature and
salinity in the Black Sea are analyzed on the basis of the archival deep-water data accumulated in
1955–1998. It is shown that, in order to describe the space variability of large-scale deep-water
characteristics of the temperature fields with reasonable accuracy, one can use both the data of
standard hydrological measurements and the CTD data. In this case, the systematic errors are
practically indistinguishable against the background of random errors whose characteristic level
is equal to
The random errors of evaluation of salinity are as large as about
the corresponding systematic errors are not distinguished. The available archive of the data of
deep-water measurements enables one to select space structures with characteristic dimensions of
in the latitudinal and longitudinal directions with temperature and salinity inhomogeneities
respectively. This is sufficient to confirm the fact of eleva-
tion of the bottom temperature in the central part of the sea is by about
with its peripheral parts.
The literature devoted to the analysis of archival data does not give a description of the space and time vari-
ability of large-scale deep-water fields of temperature and salinity in the Black Sea. At depths greater than
even the long-term average space distributions of temperature and salinity are studied quite poorly [1– 3].
This is explained by the low natural variability of deep-water characteristics, small amount of the available data
of observations, and their low quality. As a result, the variations of temperature and salinity in the deep-water
layers of the Black Sea have the same order of magnitude as measurement errors and, hence, the analysis of the
regularities of space and time variability of the large-scale fields of temperature and salinity for deep-water lay-
ers of the Black Sea becomes quite difficult . Thus, the elevation of the bottom temperature in the central part
of the sea as compared with its peripheral parts detected in  was not confirmed in a series of works published
later. Moreover, even the difference between the average values of the
S-indices of the bottom Black-
Sea waters obtained by different authors can be significant (this problem is discussed in ).
The archival data contain mainly the results of deep-water observations of the following two types: Stan-
dard water-sampling (bathometric) observations (in what follows, they are called BTM data because this abbre-
viation is used in the standard archive ) were the sole source of information till the 1960s and predominant till
the 1980s of the last century. For the last ten years, the overwhelming majority of the data of observations were
obtained using CTD sounding complexes introduced in the 1960s (Fig.
1). Unlike bathometric observations, the
accuracy of the CTD data substantially improved in the process of development of measuring instruments and
the procedures of program control and error correction.
Indeed, the standard procedure of observations guaranteed the possibility of measuring temperature and sal-
inity with an accuracy of up to
respectively, and the error of evaluation of the depth of an
instrument was about
(at depths of
for the entire period of observations.
Marine Hydrophysical Institute, Ukrainian Academy of Sciences, Sevastopol. Translated from Morskoi Gidrofizicheskii Zhurnal,
47–57, July–August, 2003. Original article submitted May 27, 2002; revision submitted June 13, 2002.
0928-5105/03/1304–0233 $25.00 © 2003 Plenum Publishing Corporation 233