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1.
Vladimir Sabinin 《Geofísica Internacional》2013,52(4):311-320
New computational techniques of QVOA analysis (Quality factor Versus Offset and Azimuth) for fracture characterization are developed. The techniques are applied to synthetic surface data of reflection with noise. 相似文献
2.
Satellite images of the sea surface demonstrate different dynamic processes at the water–air boundary and in the water layer. The objective of this investigation is to identify the fine structure of flows in the mesoscale vortex with the help of a specially developed method for flow estimation by ship wakes in the sea. The method described in this work made it possible to identify the jet nature and surges of flows in the mesoscale cyclonic vortex in the southern part of the Baltic Sea after long western and southwestern winds. 相似文献
3.
The variability of the parameters of semidiurnal internal tides in Mamala Bay (Oahu Island, Hawaii) was investigated using the experimental data obtained with ADCP bottom current profilers and ther-mistor strings. It was stated that the size, shape, and orientation of the orbits, as well as the sign of the rotation of the orbital currents, are rarely similar to those characteristic of progressive internal waves on a rotating Earth. It is supposed that such unusual features of the orbital currents are related to the interference of the waves that arrive from the straits rimming Oahu Island and to the waves that, under favorable conditions, are episodically generated at the shelf edge of Mamala Bay. Due to the fact that the floor inclinations of the shelf in the bay are supercritical for semidiurnal internal tides, the local generation of internal tides is poorly efficient. 相似文献
4.
Despite the intense attention paid to internal wave (IW) investigation, the most experimentally studied and theoretically
described are internal gravitational waves in shelf zones of oceans and tidal seas appearing during the interaction of tidal
currents with the margin of the shelf. Information on surface manifestations of internal waves in enclosed seas, such as the
Black and Caspian seas, is almost absent. In this paper, the results of study of the peculiarities of generation and propagation
of nontidal internal waves are presented; the study is carried out on the basis of combined analysis in data of marine surface
radiolocation and data of optical and infrared satellite-borne sensors. The experimental basis of investigation is radar images
of the marine surface derived with the help of Synthetic Aperture Radars, onboard the Envisat and ERS-2 satellites. Additionally,
the data of the following sensors belonging to the optical and infrared ranges were used for the purpose of radar image interpretation:
MODIS (onboard the Aqua/Terra satellite), MERIS (Envisat), and AVHRR (NOAA). Surface manifestations of IWs in the northeastern
part of the Black Sea and in the Caspian Sea have been found in radar imagery for the first time, their pattern of spatial
and temporal variation has been reconstructed. The possible factors leading to generation of the observed nontidal IWs are
determined and suppositions about the corresponding generation mechanisms are made. In particular, the IW manifestations recorded
in the northeastern part of the Black Sea are localized in the vicinity of the boundaries of eddies or hydrological fronts;
this fact evidences for the frontal mechanism of generation, at which IWs are radiated by a nonstationary (moving and/or inertially
oscillating) front. The most probable main sources of generation of IWs detected in the Caspian Sea are longitudinal one-knot
seiches, whose knot point is located near the Apsheron sill. 相似文献
5.
O. Yu. Lavrova M. I. Mityagina K. D. Sabinin A. N. Serebryany 《Izvestiya Atmospheric and Oceanic Physics》2011,47(9):1119-1126
Results of satellite observations of surface manifestations of internal waves in the Caspian Sea are presented. It is proposed
that the possible cause of generation of the revealed internal waves is uninodal seiches with a nodal line located in the
vicinity of the Apsheron Sill. The basic parameters of internal waves in the Caspian Sea, having the form of classical soliton
trains, are determined. Seasonal variability of surface manifestations of the internal waves is revealed. The horizontal current
velocity of the solitons is assessed. According to the estimation, velocity is about 0.2 m/s, which is sufficient for wind
ripple modulation. 相似文献
6.
V. G. Bondur Yu. V. Grebenyuk S. I. Muyakshin K. D. Sabinin 《Izvestiya Atmospheric and Oceanic Physics》2011,47(2):233-240
This paper analyzes the results of investigations into extremely large releases of current velocities registered by an acoustic
Doppler profiler during experiments performed on the Hawaii shelf. An integral analysis of the variability of current fields
relies on the profile data of current velocities, temperature, and acoustic-scattering layers. Based on these investigations,
we proposed a hypothesis stating that the small-scale variability of currents in profiler data is conditioned by the passage
of fine vortices emerging in the outflow and rise of freshened waters from a subsurface sink near the shelf edge. To confirm
this hypothesis on the emergence mechanism of the observed releases of current velocities, we conducted a mathematical simulation
of the response that the Doppler meter has to the passage of fine vortex, which revealed a good agreement between model calculations
and experimental data. Similar phenomena were also found in the Gelendzhik Bay of the Black Sea. 相似文献
7.
The data of acoustic Doppler profilometers placed at the edge of the steep shelf of Oahu Island, Hawaii, are analyzed for the currents. The specific character of inertial oscillations is revealed in the region: strong elongation of inertial orbits, a large amount of anomalous (cyclonic) current rotation, and sharp weakening in the divergence layer of the background (low-frequency) oscillations, the strong variation of which results in significant deviations of the effective inertial frequency from its local geographical value. It is suggested that cyclonic rotation of the inertial currents is related to a strong decrease in the effective oscillation frequency of the oceanic waves on the shelf. 相似文献
8.
K.?D.?Sabinin G.?K.?KorotaevEmail author 《Izvestiya Atmospheric and Oceanic Physics》2017,53(3):352-358
Inertial oscillations observed in the seas and oceans are frequently characterized by various hodographs of current velocities different from circular anticyclonic motion as follows from the simplest model. It is supposed in [1] on the basis of the data analysis of measurements carried out on the shelf near Gelendzhik in the autumn of 2009 that the observed distortions of hodographs of inertial currents are the consequences of superposition of inertial oscillations and background shear current. In this work we construct a simple model of inertial oscillations over the background of a shear current based on the exact solution of shallowwater equations, which generally confirms the hypothesis suggested in [1]. 相似文献
9.
V. G. Bondur K. D. Sabinin Yu. V. Grebenyuk 《Izvestiya Atmospheric and Oceanic Physics》2017,53(1):120-126
The analysis of inertial oscillations on the Gelendzhik shelf of the Black Sea is presented. Spectral characteristics of the current fields are studied based on the measurements taken by the acoustic Doppler current profiler. Strong variability of the inertial oscillation hodographs at variations in the background shear current and diverse forms of inertial oscillations measured at a fixed point at various values of the shear current are revealed. The relation between the passage of the multidirectional jets and the trains of inertial oscillations inside the jets in the studied region are established. 相似文献
10.
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