共查询到20条相似文献，搜索用时 31 毫秒
1.
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
2.
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
3.
A. A. Slepyshev 《Physical Oceanography》2000,10(5):401-418
In the Boussinesq approximation, we study baroclinic topographic waves trapped by the flat meridional slope. The existence
of these waves is explained by stratification, inclined bottom, and Earth's rotation. We deduce the evolutionary equation
for the square of the envelope of a narrow-band wave packet of trapped waves. In the second order of smallness relative to
the wave amplitude, we find the mean fields of velocity and density induced by the packet. It is shown that, in the limiting
case of weakly nonlinear plane waves, the induced current is zonal. In the Northern hemisphere, depending on the slope of
the bottom γ1, the sign of the phase velocity σ/k (k is the zonal wave number) is either always positive (for γ1>γ1cr) or always negative (for γ1<γ1cr). If we neglect the vertical component of the Coriolis acceleration, then γ1cr=0.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
4.
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
5.
I. N. Okhotnikov 《Physical Oceanography》1999,10(2):169-174
We construct a numerical model of the evolution of the structure of an oceanic thermocline in the presence of “salt-finger”
convection. The model explains the formation of a piecewise homogeneous vertical structure of the temperature and salinity
fields in the ocean.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
6.
N. A. Panteleev 《Physical Oceanography》1999,9(6):405-416
We present an analytic survey of a series of works devoted to the direct methods for the investigation of turbulence in natural
basins originated under the guidance of A. G. Kolesnikov in the 50s. We describe the principal results of the early stage
which formed the basis for future investigations. The main scientific directions of the latest period are also considered
from the viewpoint of the development of Kolesnikov's ideas: investigation of the processes of generation and energy supply
of small-scale turbulence, relationship between turbulence and the fine vertical structure and internal waves, and the mechanisms
of vertical turbulent exchange in the ocean. A model of vertical exchange under the conditions of intermittent “source” turbulence
is distinguished. We also discuss the directions of development and prospects of the investigation of turbulence.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
7.
On the basis of the satellite and ship data of many-year observations, we parametrize the albedo of the ocean-atmosphere system
both for the conditions of “fair weather” and for the maximum and climatic optical thicknesses of oceanic clouds. These results
are used to develop a procedure of practically exact reconstruction of the monthly average fluxes of integral solar radiation
and the radiation budget over the ice-free surface of the oceans according to the data of satellite measurements of albedo
(Nimbus NOAA satellite, 1974–1983) for arbitrary conditions of transparency of the atmosphere and cloudiness. We determine the current
and climatic monthly average values and the characteristics of interannual variability of all components of the radiation
mode of the ocean-atmosphere system with a spatial resolution of 500×500 km.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
8.
The evolution of an ensemble of intense vortices in the β-plane is numerically simulated. In the process of evolution, vortices
interact either directly or by means of the Rossby waves emitted by them. We show that the mean displacements of vortices
of the ensemble along the meridian and, as a result, their energy losses are lower than for the isolated vortices evolving
in the β-plane. This means that they are more stable than the isolated vortices. In addition, for vortices in the ensemble,
the theoretical dependence of the energy of a vortex on its displacement from the initial latitude obtained for the motion
of an intense isolated vortex in the β-plane is in good agreement with the experimental data.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
9.
The results of shipboard measurements of the modulation characteristics of 3.2 cm radar signals scattered by a rough sea surface
at low grazing angles are reported. The experiments were carried out from on-board a drifting research vessel in the Atlantic
trade wind zone at wind speeds of 7–10 m s−1 and coinciding directions of the wind and waves. Azimuthal isotropy of the modulation spectra was observed. It is emphasized
that the ‘sea surface-scattered signal’ modified modulation transfer function is somewhat larger for horizontal polarization
than for vertical polarization.
Translated by V. Puchkin. 相似文献
10.
We analyze the dependence of climatic variations of the location of the upper boundary of the hydrogen-sulphide zone in the
Black Sea on the variations of the sea level and various types of atmospheric circulation (according to A.A. Girs). It is
discovered that the level of correlation between the indicated parameters is high and that the corresponding plots are in
good qualitative agreement. The accumulated results enable us to make an assumption that there exists an 80–100-yr cycle of
variation of all analyzed parameters and that the long-term variations of the location of the upper boundary of the hydrogen-sulphide
zone can be regarded as a manifestation of global climatic variations.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
11.
We study possible mechanisms of mixing in the northwest part of the Tropical Atlantic (C-SALT) and show that homogeneous layers in the staircase structure can be observed across the entire frontal zone of the North
Equatorial Countercurrent. In the central region of the frontal zone, one may observe horizontal motions of the upper parts
of quasihomogeneous layers with respect to their lower parts and an essential role in the exchange processes is played by
turbulence. The peripheral regions of the frontal zone are characterized by the presence of horizontal advection and isopycnic
mixing. Far from the frontal interface, the principal contribution to the exchange processes is made by double diffusion.
We demonstrate that, for the analysis of the vertical buoyancy fluxes caused by salt fingers, one can use both the Stern relation
and the “law of 4/3”.
Translated by Peter V. Malyshev and Dmitry V. Malyshev. 相似文献
12.
We describe the hydrological structure of waters of the Persian Gulf and its seasonal variability according to the data of
CTD surveys carried out in February–June 1992 in the course of the cruises of the NOAA R/VMt. Mitchell aimed at the analysis of the consequences of the ecological catastrophe caused by the spread of oil spots formed as a result
of war operations in the Persian Gulf in 1991.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
13.
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
14.
A. A. Sizov 《Physical Oceanography》2001,11(3):259-270
We study the interannual and seasonal variability of hydrometeorological fields in some regions of the Atlantic-European sector.
These low-frequency processes are analyzed depending on the index ΔP (an analog of the index of the North-Atlantic Oscillation). It is shown that the average value of the index ΔP over the winter natural synoptic season can be used for the determination of stable locations of the centre of the Azorean
maximum in 1971–1980 and 1981–1990, the typical state of cloudiness in the Atlantic-European sector, and the fields of precipitations
and atmospheric temperature in some regions of the Crimea. Typical anomalies of the fields of precipitations and atmospheric
temperature over the west and south coasts of the Crimea are described. The signs of the anomalies of precipitations in the
winter natural synoptic season are in good agreement with the signs of the corresponding anomalies of the field of cloudiness
in the Black-Sea region.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
15.
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
16.
N. B. Shapiro 《Physical Oceanography》2000,10(6):513-531
We discuss the results of numerical experiments carried out within the framework of a new version of the quasiisopycnic model
of the Black Sea [1, 2]. We take into account the stochasticity of the wind stress, vertical shift of the flow velocity in
the upper quasihomogeneous layer, and diapycnic mixing. We generalize the procedure of “convective adjustment,” which enables
us to consider the propagation and transformation of waters of the Sea of Marmara. It is shown that the consideration of these
factors enables one to determine the structure and seasonal variability of hydrothermodynamic fields in the sea more correctly.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
17.
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
18.
S. I. Kondratev V. V. Dolotov Yu. G. Moiseev Yu. T. Shchetinin 《Physical Oceanography》2000,10(3):257-272
We performed a search for local coastal submarine springs of fresh water in the region from Cape Feolent to Cape Sarych (down
to an isobath of 40m). Stable submarine springs of brackish water with the minimum salinity of 5.5‰ and the minimum total
output of 30,000 m3/day were discovered only near the west wall of Cape Aiya. It is shown that brackish waters discharging from these springs
spread over the sea surface in the form of a thin layer (up to 1 m in thickness) characterized by lower salinity, higher transparency,
and an elevated content of silicic acid. We make a conjecture that the appearance of 2–3-m-thick layers of water with higher
transparency and lower salinity at depths of 5–8 m is explained by the discharge of unknown bottom springs of underground
fresh water.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
19.
We study the influence of floating broken ice on the mean nonzero displacements of liquid particles in nonlinear running surface
waves. The analysis is performed on the basis of a uniform asymptotic expansion (up to the quantities of the third order of
smallness as compared with the potential of the velocity of motion of liquid in a basin of finite depth) obtained by the method
of multiple scales.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
20.
V. A. Blinkov 《Physical Oceanography》1999,10(2):183-192
We describe the characteristics of a towed complex used for measurements in the upper layer of the ocean under the conditions
of periodic deepening and lifting (scanning) of a carrier with sensors connected with the ship by a weight-carrying cable
of constant lengt. For a maximum scanning range of 0–200 m and a towing speed of up to 12 knots, the measurements were performed
every 1.5–2.0 km. The minimum vertical scale of recorded temperature and conductivity inhomogeneities is 0.05–0.08 m. We present
the results of measurements carried out by the towed complex in a section of the frontal zone in the north-east part of the
Tropical Atlantic.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献