Physical Oceanography, Vol.
ANALYSIS OF OBSERVATIONS AND METHODS FOR CALCULATING
HYDROPHYSICAL FIELDS IN THE OCEAN
HORIZONTAL AND VERTICAL STRUCTURE OF GEOSTROPHIC CURRENTS
IN THE BLACK SEA ACCORDING TO THE DATA OF THE SUMMER SURVEY
PERFORMED AS A PART OF THE COMSBLACK-92 PROGRAM
N. P. Bulgakov, A. A. Eroshko, V. M. Kushnir, and A. M. Suvorov
We describe the methodology and software developed for the numerical analysis of the charac-
teristics of the horizontal and vertical structure of geostrophic currents. We present the results of
computation of these characteristics according to the data of the summer survey of the Black Sea
carried out as a part of the ComSBlack–92 program. The distinctive features of the space struc-
ture of geostrophic currents discovered as a result and the established parameters of their vari-
ability may supplement the existing data on the current field in the Black Sea.
To perform fundamental oceanological investigations of the Black Sea and realize various applied projects
connected with the utilization of its resources, it is necessary to have information on the space structure of sea
currents. The most complete data can be given by long-term synchronous measurements carried out by autono-
mous measuring devices mounted on a fairly dense grid of buoy-based stations. Unfortunately, at present, the
required data are absent and there is no real possibility of getting them in the future.
At present, we know about 700 buoy-based stations performed in the Black Sea with devices continuously
operating for periods varying from one day to several months. However, the locations of these buoy-based sta-
tions and times of measurements are insufficient to reproduce the complete space structure of the current field.
More advanced instruments [contact and distant (Doppler) profilometers] have appeared relatively recently. Un-
fortunately, at present, they are not extensively used for systematic three-dimensional surveys of the Black Sea
aimed at the creation of the maps of currents based on the data of direct measurements.
Due to the insufficiency of these data, the maps of currents in the Black Sea are now plotted, as a rule, on
the basis of geostrophic calculations or by using various hydrodynamic models of the basin. For the first time,
this approach was used by N.
Knipovich to substantiate the scheme of currents in the upper layer of the Black
Sea on the basis of the data of the first hydrological expeditions carried out at the end of the 19th century .
Later, in the process of accumulation of new data, this scheme was refined and improved . After the appear-
ance of new high-precision hydrological probes and advanced computers for processing the data of measure-
ments, the numerical analyses of the Black-Sea currents over the field of density were performed repeatedly, in
particular, by using the standard dynamic method. Note that the GIDROLOG program created by V.
tov is one of the most popular software packages for this kind of computations.
A new software package developed by A.
Eroshko with the aim of subsequent development of the tech-
nique of computations of geostrophic currents has the following distinctive features:
Marine Hydrophysical Institute, Ukrainian Academy of Sciences, Sevastopol. Translated from Morskoi Gidrofizicheskii Zhurnal,
53–64, March–April, 2002. Original article submitted June 5, 2000; revised version June 12, 2000.
104 0928–5105/02/1202–0104 $27.00 © 2002 Plenum Publishing Corporation