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1.
We analyze the data of investigation of the intrusive structure of the Gulf-Stream frontal zone obtained in making frequent drift sections with the help of an MGI-8102 probing complex, study the regularities of variation of temperature, salinity, and density along separate intrusions, and present a series of results connected with the specific features of initiation and development of intrusions and the types of exchange processes determining their transformations. It is shown that the T-diagrams of all intrusions are well separated into segments with different slopes. Moreover, by comparing the slopes and locations of these segments with each other and with the T-diagrams of the Gulf Stream and slope waters, we can fairly reliably attribute the corresponding segments of intrusions to one of the following four types: initial dynamic folds of the frontal zone, layers of domestic water separating the intrusive segments of foreign water from each other, intrusive segments characterized by the penetration of ambient water, and segments not intrusive initially but getting the required slope as a result of interaction with upper and lower intrusive segments. For segments of the last two types, it is possible to specify the predominant type of exchange. 相似文献
2.
Doklady Earth Sciences - Physical simulation of how a large shear zone forms in terms of an elastic-viscoplastic model of the lithosphere is conducted, and computer processing of the obtained photo... 相似文献
3.
Optimization of mooring observations in Northern Bering Sea 总被引:1,自引:0,他引:1
The problem of the optimal sampling strategy for moored current velocity observations in the Northern Bering Sea is addressed. We analyze dynamically induced correlations in the North Bering Sea currents and conduct their sensitivity analysis to optimize positions of a limited number of moorings. Optimization of the sampling strategy is performed with respect to robustness of the reconstruction of the North Bering Sea circulation with a particular emphasis on the accurate monitoring of the mean Bering Strait transport. Computations reveal four major regions in the North Bering Sea basin that are highly correlated with the Bering Strait transport. Apart from the regions within the Bering Strait itself, they include the Anadyr Strait and a region 100 km south of the Cape of Prince of Wales. Results of the sensitivity analysis are tested in the framework of twin data experiments with the quasi-stationary and oscillatory background circulations. 相似文献
4.
In recent years, monitoring offshore surface circulation in the Arctic Ocean with high frequency radars has become an issue of increasing practical importance. In this study, radar positions are optimized by minimizing the reconstruction errors of the surface currents in the Southeastern Chukchi Sea. By means of an adjoint sensitivity technique it is shown that in the case of a pair of radars, their optimal (i.e. most favorable) location is at Kivalina, a settlement near the strongest outflow of the Alaskan Coastal Current from the monitored domain. The least favorable location is at Shishmaref, a settlement near relatively weak inflow into the region as observed from the coast. However, if two pairs of radars are available, the best locations are Kivalina and Shishmaref. The results are verified using observational system simulation experiments (OSSEs) performed in the framework of a 4-dimensional variational assimilation of simulated radar observations into a numerical model. It is shown that correct specification of the first guess solution is of primary importance for obtaining realistic results from both adjoint sensitivity analysis and OSSEs. This emphasizes the necessity of obtaining accurate high resolution climatologies for future ice-free offshore regions in the Arctic. 相似文献
5.
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
6.
An anticyclonic eddy with a horizontal dimension of 20 km travelling north-westwards at a speed of 10 cm/s has been found during an experiment carried out off the Black Sea coast. Dynamic instability owing to horizontal velocity shear could be the reason for its origin. The eddy's passage favours the development of shear instability and the generation of short-period internal waves.Translated by Mikhail M. Trufanov. 相似文献
7.
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
8.
Z. Aslan I. F. Bikmaev É. A. Vitrichenko R. I. Gumerov L. A. Dembo S. F. Kamus V. Keskin U. Kiziloglu M. N. Pavlinsky L. N. Panteleev N. A. Sakhibullin S. O. Selam R. A. Sunyaev I. Khamitov A. L. Yaskovich 《Astronomy Letters》2001,27(6):398-403
The AZT-22 telescope installed in Turkey (Antalia) was aligned and tested on stars by the Hartmann method. The rms normal deviation of an equivalent optical system is 0.040±0.016 µm. The circle of confusion is 0.40±0.04 arcsec in diameter at a 50% energy level. 相似文献
9.
G. G. Panteleev M. N. Koshlyakov E. G. Morozov R. Yu. Tarakanov A. Yu. Goldin A. Yu. Shcherbina M. Ikeda 《Oceanology》2006,46(6):772-783
Computation of ocean currents in the Drake Passage is carried out with variational assimilation of the data of the hydrographical section across the Drake Passage carried out on December 11–15, 2003, and other data. A stream-eddy structure of the easterly Antarctic Circumpolar Current and a westerly current on the Antarctic Slope are obtained. Water transports by the different current field components and the integral transport across the Drake Passage are estimated. The necessity of direct current measurements in the Drake Passage for a correct estimate of the transport is confirmed. 相似文献
10.
The method of asymptotic multiscale expansion is applied to determine the mean current velocity and density fields induced
by a packet of internal waves. In the limiting case of a weakly non-linear plane wave, heat, salt, and impulse vertical transport
is conditioned by the vertical component of the Stokes drift velocity, which is non-zero, when turbulent viscosity and diffusion
are considered. As the wave period decreases, the wave fluxes of heat, salt, and impulse increase. In shallow waters, these
fluxes become more vigorous and may be comparable to the respective turbulent flows or even to be more powerful.
Translated by Vladimir A. Puchkin. 相似文献