Investigation of the electromagnetic fields induced by sea wave motion

This paper discusses a theoretical model of the electromagnetic field induced by internal waves of baric origin. Comparison of thein situ data on the differences between the horizontal electrical field potentials conditioned by internal waves in some Black Sea and tropical Atlantic areas and of the results of calculations of the model electrical field's intensity in those areas shows their good agreement. The dependences of the electromagnetic field component amplitudes on the internal waves parameters and sea-bed rock conductivity are considered. Translated by Vladimir A. Puchkin.     

Optimal interpolation of the data of remote sensing of the sea surface

We analyze the statistical structure of the data of remote sensing of the fields of surface temperature and the concentration of chlorophyll in the northwest part of the Black Sea with an aim to apply the method of optimal interpolation to the restoration of the maps of these fields according to the restricted amounts of data. We determine the scales of smoothing for the selection of the random components of the fields and estimate their difference from the statistical model uniform and isotropic over the space correlation coefficients. The functions of spectral densities are constructed along various sections and the best intervals of discretization of the fields required to perform the optimal interpolation with given accuracy are determined. It is shown that the construction of the maps of fields under the conditions of controlled accuracy of reconstruction of their values remains possible even if the amounts of the input satellite data are significantly decreased. We consider a procedure of evaluation of the best possible amounts of data required for the use of the method of optimal interpolation. Some examples of application of this procedure to the data of remote sensing of the fields of surface temperature and the concentration of chlorophyll are presented.     

Seasonal freshening and salinization of waters in the Karkinit Bay

On the basis on the experimental hydrological data accumulated in the database of the Marine Hydrophysical Institute of the Ukrainian National Academy of Sciences and the meteorological data of the Marine Department of the Ukrainian Scientific-Research Hydrometeorological Institute, we study the characteristics of seasonal variability of the processes of renewal, freshening, and salinization of waters in the Karkinit Bay. We analyze and estimate the repeatability of the inflows of salt and freshened waters from the sea as well as the variations of the areas occupied by these waters in the water area of the bay depending on the seasonal and wind conditions. For the spring-summer period, we estimate the period of renewal of waters in the upper layer of the main part of the bay (11–14 days). A time interval of possible absence of noticeable water exchange between the main and east shallow parts of the bay (of about two months) is revealed in the summer-autumn period. __________ Translated from Morskoi Gidrofizicheskii Zhurnal, No. 4, pp. 24–39, July–August, 2007.     

Numerical Analysis of the Electromagnetic Fields Induced by Wave Motions in the North Part of the Aegean Sea

The results of investigations of internal waves carried out in three test ranges located in the north part of the Aegean Sea and characterized by different dynamics of wave motions and water masses are used to study the electromagnetic waves induced by wave motions. We analyze their dependence on the period of waves and wavelength, reveal specific features of the behavior of the electric and magnetic fields and their phases as functions of depth, and compare the intensities of electromagnetic fields obtained under different hydrological conditions.     

Characteristics of trapped topographic waves in the northwest part of the Black Sea

We study trapped baroclinic topographic waves in the northwest shelf of the Black Sea for the actual slopes of the bottom and stratification. The time scales of trapped waves are determined. The space scales of the amplitude of oscillations are computed. It is shown that the vertical distribution of the amplitude of oscillations is in qualitative agreement with the experimentally observed distribution. The energy of topographic waves trapped by the sloping bottom is concentrated in the bottom layer, which agrees with the data of measurements. __________ Translated from Morskoi Gidrofizicheskii Zhurnal, No. 5, pp. 44–52, September–October, 2006.     

Investigation of Frontal Zones in the Karkinitskii Bay

On the basis of the data from the databank of the Marine Hydrophysical Institute of the Ukrainian National Academy of Sciences and the data of regional marine hydrometeorological stations, we present the characteristics of the seasonal variability of temperature and salinity frontal zones and background gradients in waters of the Karkinitskii Bay. We determine the locations of the frontal zones, the values of their gradients, horizontal scales, repetition, connection with weather conditions, inflow, and direction of propagation of salt and freshened waters in the bay in different seasons of the year. __________ Translated from Morskoi Gidrofizicheskii Zhurnal, No. 4, pp. 30–42, July–August, 2005.     

Electromagnetic fields of waves in the sea stratified over density and electrical conductivity

The paper addresses the theoretical problem of electromagnetic fields induced by surface and internal waves in a fluid with continuously stratified electrical conductivity and density. Calculations of the electromagnetic fields induced by the wave motion in the tropical Atlantic have been performed considering the exponentially changing electrical conductivity in the vertical. The consideration of the electrical conductivity stratification is shown to be capable of modifying electromagnetic fields in the individual fluid layers by about 50%, and the role of this stratification is shown to increase with the growth of the wave period. Translated by Vladimir A. Puchkin.