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1.
V. F. Ivanov 《Physical Oceanography》2001,11(3):205-219
For various stratifications and different types of bottom patterns we study the transformations of solitary perturbations
of density appearing in the depth of the sea. In the two-dimensional case, under the assumption that the average dynamic characteristics
weakly vary in time as compared with the wave characteristics, we deduce the equations for mean currents and waves taking
into account vertical and horizontal viscosity and the diffusion of density. Numerical examples show that the stratification,
bottom topography, nonlinearity, mean currents, and dissipation strongly affect both the process of splitting of a solitary
wave into wave trains and their amplitude and length. The wave currents exhibit the oscillatory (train-like) character. It
is emphasized that, in the case of propagation of solitary perturbations of density with dissipation, it is also important
to take into account the combined influence of nonlinearity, currents, bottom topography, and stratification.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
2.
In the coastal zone, as a result of mixing of waters, it is difficult to identify turbulent phenomena with a spatial scale
of 0.1–1 km accompanied by strong vertical flows according to the data of measuring temperature. On the basis of the data
of direct measurements, it is shown that turbulent structures are well pronounced in the field of breaking of wind waves.
We deduce empirical estimates of the response of the intensity of wave breaking to the magnitude of divergence of the current
and develop a theoretical model of the influence of inhomogeneities of currents on wave breaking capable of describing the
experimental data.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
3.
With the help of a combined model of wind and waves, we study the influence of films of surfactants on the spectrum of short
wind waves and the parameters of the lowest layer of the atmosphere. It is shown that the films of surfactants decrease the
roughness of the sea surface as a result of suppression of short wind waves, which decreases the coefficient of resistance
of the sea surface and the coefficient of turbulent heat exchange. The maximum influence of films on the exchange coefficients
is attained forU∼10 m/s. In this case, the relative decrements of the coefficients of resistance and turbulent heat exchange are equal to
15 and 9%, respectively.
Translated by Peter V. Malyshev and Dmitry V. Malyshev UDC 551.46 相似文献
4.
É. N. Mikhailova V. A. Ivanov A. I. Kubryakov N. B. Shapiro 《Physical Oceanography》2000,10(4):305-311
We use mathematical simulation to study the response of the sea in the region of the Zmeiny Island to the action of winds
of various directions. We describe the processes of reconstruction of circulation and thermohaline structure of waters and,
in particular, the location and dimensions of the zones of upwelling and downwelling caused by water surges depending on the
direction of the wind.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
5.
We analyze the results of measurements of currents in the trains of internal solitons on the New-York shelf of the Atlantic
Ocean performed in the course of the Joint US/Russia Internal Wave Remote Sensing Experiment (JUSREX). It was discovered that
the thermocline is characterized by an almost monotonic anticyclonic variation of the direction of orbital currents in the
trains of solitons but the direction of waves in each train is practically constant. As a rule, the current significantly
deviates to the left from the direction of waves in the leading soliton and approaches the indicated direction in the rear
solitons of the train. The angular rotation current velocity corresponded to periods varying within the range 12–24h and,
on the average, was close to the local inertial period. It is shown that this rotation cannot be caused by the distorting
influence of advection of background shear currents but, most likely, is connected with the unknown properties of internal
solitons in the rotating ocean.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
6.
The purpose of this study is to investigate the influence of tidal currents on sea ice in Spitsbergen fjords which may cause rapid decrease of the ice thickness due to erosion and melting of the ice. The effect was studied in-situ near the narrow channel connecting the Van Mijen Fjord and Lake Vallunden. The strong jet-like tidal currents in the strait driven by semidiurnal tide continue into the lake preventing ice freezing along a narrow strip during high tide and relatively warm weather. Understanding the formation of open water regions or regions with thin ice is important for the safe transportation on ice. We estimate conditions and representative time over which strong tidal current influences ice thickness along a narrow strip in solid ice. Changes of tidal phase and decrease in air temperature influence freezing of the strip in one-two days. While the tidal flow leaves the strait it overflows a shallow bar and generates internal lee waves propagating downslope and mixing the water. Tidal forcing of internal waves was measured using pressure gauges and by scanning of the ice surface during flood and ebb phases. Internal waves were measured using three types of CTD instruments and an ADCP current meter. The generation of wave packets occurs every tidal cycle when the current flows into the lake, but no generation occurs during the ebb phase of the tide because the currents over the bar slope are low. Parameters of internal waves are estimated. Model simulations confirm generation of internal wave train by the tidal current descending downslope. 相似文献
7.
We the discuss the results of modelling wind currents in the system of Sevastopol bays. Numerical calculations are carried
out according to the model of Felzenbaum. It is shown that the decisive role in the formation of distinctive features of circulation
of waters and the essentially three-dimenstional character of currents in this part of the sea is played by the bottom topography
and the direction of winds. These distinctive features are demonstrated for the cases where the motion is induced by the northeast
and northwest winds. In the Sevastopol bays, we discovered the existence of jet longshore currents, vortex character of integral
circulation, and intense processes of upwelling and downwelling.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
8.
Within the framework of the linear theory of long waves, we perform the numerical investigation of transformations of a barotropic
diurnal tide in the process of its motion from the deepwater region of the sea into the region of continental slope and shelf
zone at any angle to the coast line. For a linear profile of the bottom of the continental slope and shelf, we establish dependences
of the amplitudes and velocities of waves on the direction of propagation of the tidal wave and the latitude of the place.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
9.
N. P. Bulgakov V. V. Ukrainsky Yu. I. Popov P. D. Lomakin Yu. V. Artamonov 《Physical Oceanography》2001,11(5):447-457
On the basis of the data of the complex oceanographic experiment carried out in the course of the second Ukrainian Antarctic
expedition in March 1998, we study the structure and kinematics of waters in the region of the archipelago of Argentine Islands.
The regularities of thermohaline stratification of waters are discovered. We determine the most important environmental parameters
premoting the variability of hydrophysical fields on time scales varying from several days up to a week, analyse the data
of actual observations over the currents, and estimate the relative contribtions of diurnal and semidiurnal tidal waves to
the total dispersion of hydrophysical parameters of the environment. The residual currents are filtered out. We propose a
hypothesis about the mechanism of their formation. Various types of tidal currents are revealed and the directions of propagation
of diurnal and semidiurnal tidal waves are determined.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
10.
We study the influence of baroclinic tidal waves on the diffusion of an impurity spot in a continuously stratified fluid.
The equation of turbulent diffusion is solved numerically by taking into account the wave currents. We establish the dependences
of the characteristics of the diffusion process on parameters of baroclinic waves and the location of the impurity spot.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
11.
Within the framework of the linear theory of long waves taking into account the action of the Coriolis force, we solve the
problem of generation of internal waves by a barotropic tide impinging on a bottom irregularity of the sea-ridge type. The
cross section of the ridge is assumed to be rectangular and the stratification of the ocean is regarded as stepwise with two
thermoclines (three-layer model). We study the dependences of the characteristics of generated waves on the parameters of
stratification and the period of the impinging barotropic tide.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
12.
We investigate the influence of baroclinic tidal waves on the diffusion of an impurity spot in a continuously stratified liquid.
The equation of turbulent diffusion is solved numerically by taking into account the wave currents. We establish the dependences
of the characteristics of the diffusion process on the parameters of the baroclinic wave and the location of the impurity
spot.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
13.
We discuss the results of numerical experiments modelling the process of propagation of passive impurities from the Karantinnaya
Bay caused by steady wind currents and turbulent diffusion. The currents are computed according to the Felzenbaum model for
the cases of northeast and north-west winds [1, 2]. We analyse specific features of the space and time distribution of the
impurities caused by the three-dimensional character of the currents.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
14.
We present the results of investigation of the transformation of a momentum flux coming from the atmosphere into a water reservoir
and establish the relationship between the surface velocity of the drift current and the dynamic velocity of wind. For the
initial stage of the development of wind waves, we propose a dependence that enables one to determine the momentum flux spent
for an increase in the intensity of waves via the momentum flux coming into the water reservoir from the wind. The behavior
of the ratio of the momentum flux spent for the increase in the intensity of waves to the total momentum flux coming from
the atmosphere into the water is studied depending on the dimensionless fetch and age of waves. In our analysis, we used both
our own experimental data and the data available from the scientific literature.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
15.
16.
We describe a differential approach to the spectral composition of thin thermohaline inhomogeneities in the ocean depending
on the mechanisms responsible for their generation and demonstrate the possibilities of this approach in getting realistic
hydrophysical results. The statistical classification of fine-structure fluctuations according to their origin is performed
on the basis of the joint analysis of the temperature, salinity, and density spectra computed in a section of the vertical
profile where the variation of mean gradients of all three parameters is insignificant. On the basis of the constructed mean
spectrum of wave elevations, we estimate the dissipative characteristics of the convection of salt fingers and small-scale
internal waves.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
17.
Internal waves generated by a barotropic wave impinging on a bottom ridge with continuously varying height are studied within
the framework of the linear theory of long waves. We consider the case where the diurnal tide travels at an arbitrary angle
to the axis of the ridge located in the area of a geostrophic flow caused by tilting of the free sea surface and the interface
of a two-layer ocean. We study the dependences of the amplitudes of internal waves on the velocity of the geostrophic flow,
the direction of propagation of the barotropic tide, and the geometry of the ridge.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
18.
Free waves (seiches) in a circular basin of variable depth are studied numerically within the framework of the linear theory
of long waves taking into account the action of the Coriolis force. We determine the frequencies of axisymmetric and circular
waves, study the structure of the modes of elevation of the free surface and wave velocities, and establish the dependences
of the phase velocities of circular waves on the number of mode and wavelength.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
19.
We analyze geostrophic currents with nonmonotonic vertical profiles, of velocity and present the distributions of the density
of water and hydrostatic pressure corresponding to possible types of the vertical kinematic structure. To prove the existence
of the indicated complex layered structures, we use, the data of instrumentalin situ measurements of currents in the Black Sea and in the west part of the Tropical Atlantic.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
20.
We show that the parameters of primary radar images obtained from theSich-1 satellite depend on the mode of survey and that the time dependence of the coefficient of correction of amplification in
the channel of formation of radar signals is nonlinear. We propose to process radar images of the sea surface by using the
so-called Bragg normalization of signals, which enables one to get a physically correct dependence of specific effective scattering
surface on the elevation angle. We also consider a procedure of determination of the dependence of specific effective scattering
surface of the sea on the wind velocity on the basis of the data accumulated by the side-looking radar of theSich-1 satellite.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献