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The annual course of sea level at various sections of the coastline is derived from the interpretation of empirical observations. The paper evaluates the effect of continental discharge, atmospheric pressure, and density distribution upon the local sea level vacillations, and the tendency to multi-annual sea level variability is determined. During this century, against the background of broad spectral oscillations, the Black Sea mean level is rising at the rate of 1.6 mm year−1. The paper examines Man's impact upon the erosion of the shore and the departure of the coastline.

The paper concentrates on the response of the atmospheric circulation non-tropical regions of the Northern Hemisphere to considerable sea surface temperature anomalies regularly occurring in the equatorial Pacific Ocean, related to the El Nino event. It has been established that during El Nino, zonal western circulation and meridional southern circulation tend to decay (being −2.6% and −5.4% respectively), while meridional northern circulation intensifies (+8.0%). The paper examines regional peculiarities of the non-tropical atmospheric response to the processes taking in the tropics. It is shown that atmospheric circulation reconstruction is most essential in the Siberian (10.4%) and Pacific (10.2%) sections and is minimal (4.3%) in the Atlantic region. These peculiarities of the regional atmospheric circulation reconstruction may be taken into account to predict short-term climatic variations in the Northern Hemisphere.

The paper considers the thermohaline structure of Black Sea abyssal and near-bottom waters on the basis of exact measurements recorded in recent years under the HYDROBLACK and COMSBLACK international projects. The surface water mass (along with the cold mixed layer), the intermediate, abyssal, and near-bottom masses are identified. The upper boundary of deep waters is defined as a depth level where the density ratio decreases down to 0.1 This depth roughly corresponds to the 900–1100 m depth levels. Furthermore, the paper provides potential temperature and salinily values in the near-bottom layer, with an error of, respectively, 0.002°C and 0.002‰, at most.

Relying on Shuleikin’s theory, defining the relationship between the elements of the temperature and air pressure fields, the paper provides numerical characteristics of the cyclone evolving into a hurricane on 15 November 1992. Calculated is the trade wind-induced circulation component for the western section of the Black Sea during the period of autumn-winter-time cooling of waters. The paper examines specific features of the north-west storms, Crimean bora, and breeze-induced circulation in the region.

Using archived historical data on the temperature/salinity distribution, this paper describes the structure of the mean seasonal and the actual field of the computed speed of sound in the Gulf Stream region. The formation of acoustic channels of large, medium, and small size is considered, depending on the vertical thermohaline structure of waters. The paper provides statistical characteristics of the sound speed field and acoustic channels of waters interacting in the Gulf Stream system.

The paper examines how various factors affect the intensity of photosynthesis and oxidation reaction in the north-western part of the Black Sea. In the course of the evolution of the basin, natural aspects were widely changing; therefore their role is evaluated by the content of organic matter and diatoms in the bottom sediments. The influence of anthropogenic factors is determined by the current tendencies in the variation of physico-chemical and biological characteristics of the basin. The main factor upsetting steady functioning of the north-western Black Sea ecosystem is the large biogenic influx to the sea. The possible changing of the ecosystem during the nearest few decades is assessed.

The paper describes the thermohaline structure of the Izmir waters obtained from three CTD-surveys carried out in different seasons of 1994. Also, the mechanisms responsible for the formation of the regional peculiarities and the variability of the temperature/salinity field and examined. The results of diagnosis and adaptation computations of the three-dimensional water circulation are analysed, applying a numerical model and CTD-data.

The paper addresses the problem of sea color measurements made by satellites. A special mathematical procedure is proposed for determining spectral dependence of the aerosol component of the light backscattering in the atmosphere. The procedure is based on conducting repeated observations of the same sea area after a sufficiently brief period, during which seawater properties remain virtually unchanged, while aerosol fields undergo considerable changes. Testing of this approach has been performed by two typical surveys of the Black Sea by NIMBUS-7 on June 10 and 13, 1980.

The paper concentrates on the structure and synoptic variability of the meteorological, hydrophysical and chemical fields in the Somali continental shelf area during summer monsoon. Tidal front is shown to be a typical element of the water stratification in the studied area, whose state and dynamics thoroughly in.quence the fisheries situations. It has been found out that commercial aggregations of fishes regularly pooled up and dispersed in the frontal zone, depending on the natural synoptic-scale processes taking place.

The paper discusses the results of investigations on contamination of the Sea of Azov by petroleum hydrocarbons and particulate organic matter. After cessation of open sea observations in 1992, the contamination of the sea by petroleum hydrocarbons is predicted for the period from 1993 to 1997.

The measurements data provided by an antenna of distributed temperature sensors, mounted on an oceanographic tower in the South Crimea continental shelf area, were applied to study the mechanism for the generation of short-period internal waves with anomalous amplitudes in the Black Sea. For analysis, information was incorporated concerning the background hydrological and meteorological conditions that were observed during the experiment. A mathematical model for the phenomenon under study has been constructed, and calculations of the anomalous internal wave generation have been presented. The paper contains a comparative analysis of thein situ data and simulation results, and demonstrates a good qualitative/quantitative agreement between the parameters of internal waves.

The paper examines the results of two hydrological/chemical investigations of a submarine freshwater source in the vicinity of Cape Aiya. The supposition has been confirmed that some typical chemical indices, specifically, silicic acid content, may be used to reveal such sources. The acquired data point out that the freshwater source is steady functioning, which implies that subterranean freshwater reserves in this area are substantial.

Using thein situ currents measurements conducted during Cruise 41 of the R/VAkademik Vernadsky, we have considered the structure of the Guiana Current in winter over the shelf, continental slope and in the deep-water part of the ocean, adjoining the Brazilian coast. Regular variations of the current velocity with depth have been identified, and the current velocity's stability and variability determined. The paper examines how the barocline component of the hydrostatic pressure horizontal drop influences the current velocity's vertical profile. An attempt has been made to evaluate the current's transport.

The paper discusses the results of numerical experiments on response of the Black Sea to the ‘real’ (mean monthly) atmospheric forcing. A new version of the multi-layer quasi-isopycnic model is applied which does not use the rigid-lid approximation and allows for a salt flux through the sea surface. Ways of obtaining quantitative agreement between the calculated data due only to the external forcing, without invokingin situ temperature/salinity observations are suggested.

On the basis of the experimental investigations conducted from an oceanographic tower, the variability of the structure of temperature profiles has been analysed. The paper provides a classification of the basis types of temperature profiles and determines their frequencies and duration in the annual cycle. Dynamics of the transition from one type of a temperature profile to another has been found to have synoptic scales. The variability of parameters during an occurrence of some typical profile have been assessed; it has been deduced that variations in profile shape are linked with fine structure effects of internal waves.

Archived data have been employed to calculate climatological mean monthly currents fields in the north-western tropical Atlantic Ocean, to specify monthly transports of the basic circulation elements, and to calculate the intra-annual currents parameters in the active layer. The paper provides a detailed description of seasonal variations of the currents' kinematic structure in the studied region. The North Brazil Current is shown to be most developed in October–December. During that period, its velocity at the sea surface is in excess of 1.5 m s−1. The North Equatorial Countercurrent is most vigorous in September–November, when its speed in the subsurface layer attains approximately 1 m s−1, and the rate of flow reaches 60 Sv.

The paper discusses the data derived from a numerical experiment on the ocean’s response (between the equator and 64°N) to the seasonal variability of the atmospheric forcing (wind and heat flux through the ocean surface). A multilayer (7 layers) non-linear model is used incorporating the upper mixed layer interacting with the internal layers in the regimes of entraining and subduction. The restructuring of the layer composition, the currents and temperature variability, as well as the alternation of the entrainment and subduction regimes are analysed.

The paper discusses the conditions corresponding to the largest and smallest North Atlantic Oscillations (NAOs). It is shown that in winter, when NAOs are at a minimum, the number of cyclones over the Black Sea increases. At the same time, cloudiness in the Atlantic-European section becomes heavier, compared with the largest NAO. Heavy cloudiness over the Balkan and Karpaty mountains, with NAO at a minimum, may imply the greater likelihood of Balkan cyclones’ penetration into the Black Sea region. The mechanism responsible for the generation of maximum (minimum) cloudiness in the Atlantic-European section is discussed.

A barotropic variant of a multilevel numerical model based on primitive equations of sea dynamics is applied to calculate wind-induced circulation in the Donuzlav lake. Water exchange with the open sea is considered. The paper examines several situations involving wind forcing. It shows that a two-layer system of currents occurs in the lake. The effect of the bottom topography is essential, being traceable up to the surface.

The paper considers the correlation between the variability of river discharges in the northwestern Black Sea and water salinity (from 1962 to 1994). As the most complete series, we have chosen salinity data collected at the port of Odessa. The dominant oscillations in the intra-annual variability of river discharges (Danube, Dniester, Dnieper, Yuzhny Bug) and salinity attain about 2–3 months and one year, respectively. In the inter-annual variability of river discharges and water salinity, cyclicities equal to about 4–6 months and 9–12 years, respectively, have been identified. Through analysing the inter-annual variations, an inversely proportional dependence has been found between the overall river discharges and salinity (between discharges in April and salinities in May, the correlation coefficient has amounted to −0.61). For each river, we have obtained the following dependences: for Odessa-Dniester, −0.72; and for Odessa-Danube, −0.65.

The paper considers some general laws of the dynamics of an intensive isolated eddy interacting with background vorticity, namely, the latitudinally varying Coriolis parameter, bottom topography, and a mean inhomogeneous flow. Using experimentally derived numerical data, we show the eddy’s typical behaviour in three different situations.

The paper focuses on the propagation of tsunami waves in the Black Sea and their parameters. Two tsunamis observed by tide gauges in 1927 are discussed. The waves were generated by the underwater earthquakes in the continental slope area south of the Crimea. Tsunami characteristics have been categorized and scrutinized, using tide gauge data. The finite-difference evolutionary model has been realized, which allows description of the wave field's spatial structure and computation of mareograms at a variety of coastal sites. The observed wave elements and the computed ones have been matched up for the Black Sea tsunami event that occurred on 11–12 September 1927.

The paper shows that, by virtue of the specific water circulation in the south-eastern Indian Ocean, thermal influx within the 0–200 m layer exceeds the efflux by 13.5×1015 MJ per year, which, being recalculated for the entire area, is equivalent to about 2200 MJ m−2. Computations of the heat fluxes through the sea surface in that part of the ocean indicate that thermal efflux to the atmosphere is larger than the influx of solar heat by about 1500 (on average, for the entire area), rather than by 2200 MJ m−2 per year. Hence, about 700 MJm−2 penetrate through the lower boundary of the layer and warm up the deeper ocean layers.

In term of theory for natural oscillations, the paper considers the properties of barotropic seiches in the Gulf of Izmir. To solve an eigenvalue problem, the method of determining the periods of sea level vacillations and the latter’s spatial structure has been used. Model data have been applied to determine the spatio-temporal structure of the sea level’s natural vacillations for the basic energy-carrier periods.

This paper discusses the application of acoustic sounding with the purpose of identifying vortical features in the sea. Analysis of the results of a multidisciplinary acoustic/hydrological experiment conducted in the Black Sea has revealed a stable recurrent correlation between the amplitudinal variance of echo signals, on the one hand, and the peculiarities of water temperature fields, on the other. Given these characteristics, the peripheral and the central areas of a mesoscale eddy essentially differed. This allows us to apply acoustic sounding to identify mesoscale eddies in the sea.

This paper discusses the results of a numerical experiment on modelling the seasonal variability of the water circulation and temperature/salinity fields in the Black Sea. A multi-layered quasi-isopycnic model is used based on primitive equations and incorporating the upper mixed layer (UML). It is shown that during springtime warming, relatively cold layers emerge in some areas, due to subduction, from the UML, which then spread virtually over the entire basin and persist until they become absorbed by the rapidly deepening UML during the period of cooling in winter.

This paper discusses the structure of fish and phytoplankton aggregations, using the transect characteristics method and the data collected during cruise 11 of the R/VArtemida in the South-West Atlantic Ocean. A method of phytoplankton field classification by the type of aggregation is suggested. On the basis of experimentally compiled data, a new way of determining the minimum living distances between hydrobionts has been developed.

This paper focuses on the numerical modelling of tsunami propagation in the open Black Sea. Two types of numerical models are discussed: a model for the radial propagation of long waves and an evolutionary finite-difference prognostic model. Experimentally derived numerical data on the model source of tsunamis are reported.

This paper discusses a mathematical model for the dynamics of pollution in the Arctic basin, considering spatial non-uniformities in the distribution of ecological and hydrodynamic parameters. The model features blocks simulating contaminant fluxes through the tropic chains. The results of numerical experiments are provided which demonstrate the model's capability to predict and assess the dynamics of heavy metals, radionuclides, and petroleum hydrocarbons in the Arctic basin. The model is adaptable to a global model. Climatic phenomena and anthropogenic forcing are described in the form of scenarios.

This paper focuses on the heat advection calculated for the tropical Atlantic upper mixed layer and a 0–200 m layer, using two different methods, specifically, (i) from the change in the heat content and the external heat balances and (ii) on the basis of the flows and horizontal seawater temperature gradients prescribed. Thermal advection in the upper mixed layer, in terms of its geographical distribution and the order of magnitude, coincides with that of the 0–200 m layer. This allows the deduction that basically the heat in the tropical Atlantic is transferred within the upper mixed layer. Seasonal variations of the heat advection prove to be appreciable; the annual course is well approximated by two principal waves, one having annual and the other semi-annual cyclicity, with the annual wave being predominant. Both waves reproduce 90% of the dispersion of monthly thermal advection.

This paper provides calculations and an interpretation of the mean annual sea surface temperature (SST) anomalies and the characteristics of the SST annual harmonic in the equatorial Pacific Ocean from April 1991 to February 1993, using data provided by the Russian Hydrometeorological Centre (RHC) and the US National Meteorological Centre (NMC). The magnitude of the mean annual anomalies and the SST annual harmonic amplitude in typical El Nino Southern Oscillation (ENSO) regions, as derived from the RHC data set, are shown to be smaller than their NMC data-based counterparts, due to the considerable spatial smoothing of the original data provided by the RHC. However, in terms of quality, the two data sets agree well with one another, and quantitative discrepancies are rarely larger than the standard error of mean monthly SST determination.

This paper examines the oceanographic situation in the north-eastern Arabian Sea shelf area during the period when the trade winds change. The location and intensity of the discharge front there have been found to be dictated by tidal events and the wind regime. It is shown that commercial fish shoals move over the water column along with the front and that fish catches are largest when the front is steady.

This paper reports on the interannual fluctuations of the seasonal sea surface temperature (SST) variability in the North Atlantic. The areas of intense variation of the average annual SST and predominant harmonic (annual and biannual) amplitude have been identified. A significant negative correlation between the average annual SST and the amplitude of the SST variation annual harmonic is demonstrated in thesee areas; amplitude anomalies of the dominating harmonics of interannual SST fluctuations may exceed the climatic norm by 1.5–2.0 times.

In this paper, the main results of field research into the seawater dynamics on the shelf of the Crimea in the summer of 1991 are reported. It is shown that in the ‘weather’ frequency band, the oscillations with periods of 11–12 days have the greatest amplitude. These represent coastal-trapped waves with a spatial scale of the order of the length of the Black Sea coastline. These waves are generated by distant winds and significantly disturb the response of the Crimea shelf waters to local wind forcing. A transient upwelling-downwelling circulation having a period of 5–7 days is induced by local winds and is not accompanied by the generation of trapped waves at the frequency of forcing. Since the average circulation on the shelf of the Crimea is of cyclonic character, downwelling events are found more frequently and have longer time periods than the upwelling events. The wind-generated trapped waves on the shelves of the Crimea and Kerch Peninsula have an average period of 27 h. The inertial oscillations were well expressed during an experiment resembling long-wave motions.

This paper explains the existence of some interannual oscillations in the ocean and atmosphere such as a quasi-biennial cyclicity (QBC). It is shown theoretically that the natural sign-variability of feedback, occurring in the ocean-atmosphere system with an annual period, can cause these phenomena. The QBC proves to be most effective. The effects which result from the deterministic variant of theory and the consideration of the additive and multiplicative stochastic effect in it are analysed. In this case, the stochastic effect (noise) models the higher-frequency mesoscale processes. The multiplicative noise with a ‘red’ spectrum, describing the random effect of the lowest-frequency part of the mesoscale processes on the feedback (FB) between the ocean and atmosphere, can stipulate the destabilization of the QBC regime, which becomes unsteady at certain spectra and noise variance values.

In this paper, studies carried out as a continuation of Professor A.I. Fel'zenbaum's ideas about the application of models of vartical substance distribution (temperature, salinity, density, oxygen, etc.) to the theory of sea currents with the purpose of proximate monitoring of the basic physical fields in marine and oceanic regions are reviewed. It is demonstrated that such models can be used effectively in solving problems of environment protection, in systems of sea climate management, in the prediction of the state and migration of fish and invertebrates, in the examination of marine hydrotechnical engineering aimed at the development of problem-orientated databanks serving the description of scenarios of the marine ecosystem state, and in the comprehension of the regularities of their evolution.

This paper discusses some problems related to the development of systems of global monitoring of the sea surface temperature (SST). The characteristics of the operational SST data are considered and estimations of their accuracy are given. The applications of varoous models to the computation of SST in relation to the development of an oceanographic data assimilation system are reviewed briefly.

This paper discusses the results obtained through numerical modelling of the annual course of circulation and thermohaline field evolution in the tropical Atlantic under the impact of real wind forcing (from March 1982 to March 1983) and compares them with the calculation of seasonal variability induced by the climatic wind. Changes in the pattern of the equatorial currents and related temperature fields induced by the specific peculiarities in the wind field are analysed.

This paper considers the relationship between multi-year air temperature and pressure fluctuations over the ocean, based on an approximate solution of the problem on the determination of large-scale seawater temperature anomalies from the conditions predominating at the sea surface. The dependence derived is numerically analysed using observations made in the North Atlantic. It is shown that the variability of annual mean air temperature anomalies is largely controlled by the air pressure field which has taken place during the preceding long-term period. The dependence derived may be applied to generate long-term forecasts of the ocean's hydrometeorological regime.

This paper considers the response of the eastern boundary layer and restructuring of the upwelling and downwelling regimes due to the periodic changing of the alongshore wind direction using the data from a numerical experiment conducted in the frame of a multi-layer non-linear model of the ocean, based on hydrothermodynamic primitive equations.

The paper considers the reconstruction of ocean currents from the asynchronously-compiled temperature and salinity data using three different techniques: the diagnostic method, the sequential objective analysis and the four-dimensional (4D) analysis based on dynamico-stochastic modelling. Intercomparison of the techniques is implemented on the basis of numerical model experiments carried out for the Newfoundland energetically-active area. Assessed is the accuracy of reconstruction of various hydrophysical fields using the techniques suggested. The advantage of applying 4D analysis is shown.

This paper discussesin situ observational data on the directed light attenuation index in the near-surface layer, collected in September 1987. The absolute light attenuation index has been evaluated for a near-shore strip of water 10–15 miles in width. When multidisciplinary research is conducted in the open sea, this part of the sea surface remains unstudied, as the observational grid for it is made larger than the spatial-temporal parameters of the biophysical processes producing optical inhomogeneities.