Computational algorithm for the evaluation of inclinations of the level in the problems of the dynamics of basins

We develop a method for the evaluation of inclinations of the level, which enables one to find them with high accuracy. The reliability of this method is tested by comparing the numerical solutions for inclinations of the level with analytic expressions. It is shown that the system of coupled equations for inclinations of the level can be decomposed into two independent equations with sufficiently high accuracy. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

Modelling of the ecosystem on the shelf of the Republic of Guinea

Three mathematical models are considered: a two-dimensional model for calculating the concentration fields of the ecosystem components on the shelf of the Republic of Guinea, a pointwise model for the annual variation of the components, and a two predators-prey model. These models are used to study the effect of hydrodynamic conditions on the state of the shelf ecosystem and for research into the causes which distort the balance between marketable and unmarketable fish.Translated by Mikhail M. Trufanov.     

Specific Features of the Influence of the Lower Boundary of a Waveguide on the Angular Structure of the Sound Field in the Shelf Zones in the Northwest Part of the Black Sea

We analyze the possibility of existence of critical angles of incidence of sound waves along two paths of propagation of sound typical of the northwest shelf of the Black Sea from the viewpoint of the characteristics of the lower boundary of a waveguide and the space and time structure of the field of sound velocity. The lower boundary of the waveguide may possess the property of acoustic transparency both in the case of a subsurface sound channel and under the conditions of negative refraction if the bottom is formed by fine-aleurite silts responsible for significant losses in the process of propagation of sound. The angles of total internal reflection exist for bottoms formed by shell rocks under all hydrological conditions typical of this region. At the same time, for bottoms formed by fine-aleurite silts, these angles exist only for a certain vertical structure of the field of sound velocity, which enables one to use the range of angles in which the losses caused by the reflections of sound waves from the bottom can be neglected.     

On the calculation of the depth of the upper mixed layer in the equatorial ocean

The equation for the turbulence kinetic energy balance as applied to the horizontally-inhomogeneous upper ocean layer encompassing the equatorial zone is analysed. A partial solution of the equation has been derived for the equilibrium conditions. Using the equatorial Atlantic as an example, the prime importance of considering the effect of horizontal heterogeneity in calculating the upper mixed layer thickness is shown.Translated by Vladimir A. Puchkin.     

深度基准面的最低潮意义不一致性问题分析

因资料时长、算法实现等差异,长期验潮站的深度基准面L值存在最低潮意义不一致问题。通过对北方海区长期站的算法实现考证,表明最低潮意义不一致是普遍现象。从三个层次提出了解决方案:(1)对于一般测量作业单位,以不同传递方法的结果判断最低潮意义一致性,以保持L值空间连续分布为原则取值;(2)对于基础海洋测绘管理部门,应构建全海域的深度基准面模型,作为基础数据集提供查询与内插的公众服务;(3)对于国家层面的多部门统筹,应统一深度基准面的历元与算法实现,建立基准维持与调整的长效机制。     

Reconstruction of the Linear Distribution of the Squared Buoyancy Frequency According to the Known Dispersion Properties of the Field of Internal Waves

We propose a method for the solution of the inverse problem of reconstruction of the vertical stratification of density in the ocean according to the known dispersion curves for internal gravity waves. For the stratification of density modeled by a linear distribution, we determine the accuracy of its reconstruction for values of the frequency of oscillations and wave numbers given with different degrees of accuracy. The posed problem is studied in the Boussinesq approximation for two traditionally used types of boundary conditions on the surface of the fluid. We deduce dispersion equations and focus our attention on their asymptotic analysis. An asymptotic solution of the inverse problem is constructed and its sensitivity to the degree of accuracy of the input data is investigated.     

Spectrofluorometric studies of the aromatic hydrocarbons in the bottom sediments and water mass of the western sector of the arctic region

The results of the treatment of the database on the spectrofluorometric studies of aromatic hydrocarbons (AHC) [over 500 bottom stations] allowed the authors to show the high informativity of the technique used not only for geological environmental studies but also for gaining knowledge of the genetic parameters of the organic matter. The principal spectral characteristics of the bottom sediments were established for different lithofacies groups of sediments. The results obtained, which were verified by the data of the chromatographic mass spectrometry, allow one to consider the research method developed to be suitable for multipurpose geochemical surveys.     

Evaluation of the effects of the communication cable on the dynamics of an underwater flight vehicle

This paper presents a numerical scheme to evaluate the effects of the communication cable attached to an underwater flight vehicle. Both simulation and model validation results show that the numerical scheme is effective and provides a means for developing a feed-forward controller to compensate for the cable effects when developing an autopilot for the tethered vehicle. Moreover, the numerical scheme can also be applied to predict the effects of the ROVs umbilical during its deployment.     

Gonadal cycle of the dwarf oyster Ostreola stentina from the south of the Gulf of Hammamet on the eastern coast of Tunisia

The reproductive cycle of the dwarf oyster Ostreola stentina (Payraudeau 1826) at Monastir in the south of the Gulf of Hammamet on the east coast of Tunisia was studied using condition indices and histological techniques. The species was shown to be a protandric hermaphrodite. Whereas males dominated the small shell length categories (12.45–34.99 mm), females (21.00–47.16 mm) and hermaphroditic individuals (30.00–57.95 mm) become more predominant with increasing size, suggesting that individuals may undergo protandric development. The overall male to female ratio was 1.0:1.7. Gametogenic development begins in February–March for females and in September for males, and spawning occurs during April and July for females and December and July for males. There was a clear relationship between the gonadal condition index and gametogenic stage for both sexes. Values increased from zero in their early stage of development and peaked during ripe and spawning stages, before decreasing in the spent stage. However, the meat condition index did not show any statistical differences between gametogenic stages.     

A model of the dynamics of the ecosystem of the Sea of Azov

We use many-year archival observations of hydrologic and hydrobiologic state of the Sea of Azov for the identification of the structure of a model of its ecosystem. The ecosystem model, supplemented with expert estimates of bioresource consumption (fish reserve), contamination level, and possible ecologic fines for violation of the sea natural state, is formalized by the method of system dynamics. Hereat, the major part of influence functions is found in terms of observational data with application of self-organization algorithms. We also present the results of simulated experiments with the model of the ecosystem, which enable us to analyse scenarios of its behaviour under the influence of various external factors (wind, river discharge, water exchange with the Black Sea, etc.). Translated by Peter V. Malyshev and Dmitry V. Malyshev     

《京都议定书》的缺陷分析

自我加强型（self—enforcing）机制是促进气候变化国际协议中各缔约国积极参与温室气体减排的最为关键的激励机制,然而却是《京都议定书》这一国际协议所最欠缺的,致使诸多缔约国消极应对,甚至单方面退出协议,令协议至今难以有效实施。因此如何建立并完善自我加强型的激励机制是《京都议定书》在未来的机制和内容改进中应关注的重要研究领域。作为这个研究领域的1个关键的前提条件,必须对目前议定书存在的缺陷和问题具有充分和深入的认识。     

Relatioship between the intensity of tsunami and the location of the epicentre of underwater earthquakes near the continental slope of the South Coast of Crimea

Within the framework of the nonlinear theory of one-dimensional long waves, we performed the numerical analysis of the dependence of the intensity of tsunami on the shelf of the South Coast of Crimea on the location of the epicentre of underwater earthquakes near the continental slope of the basin. The calculations were carried out for the parameters of the model corresponding to the Yalta tsunami of September 12, 1927. It is shown that, for the same magnitude of the earthquake, the smaller the distance from its epicentre to the coastal line, the lower tsunami waves in the coastal zone and the smaller their vertical run-up. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

Analyzing Conditions for the Occurrence of the Voice of the Sea on the Basis of Infrasound Measurements

Izvestiya, Atmospheric and Oceanic Physics - Conditions for the occurrence of the “voice of the sea” within the infrasonic range are studied and its parameters are determined from...     

Approach to the geostrategy of the oceans: The case of the mediterranean

It is known that by the general ‘geostrategy’ for the oceans we mean the behaviour of countries of the world in defending their own vital economic interests as projected on different oceans. The means for protecting national interests can be economic, political, diplomatic or military. This paper dwells in particular on these last aspects, offering in the first part some useful reflections on the analysis of regional seas. The second part gives elements for the understanding of the complex Mediterranean situation where the East-West confrontation is accentuated by widespread economic, political, ideological and ethnic contrasts between coastal states. For these reasons this sea can be defined as one of the most unstable and belligerent regions in the world.     

Modelling of the spectral characteristics of the wind wave envelope

A method applied for the determination of the statistical characteristics of the wind wave envelope is considered. It is shown that the correlation function envelope for a normal random process defines the basic properties of the process envelope and it can be expressed through the spectrum width. No limitations are imposed on the form or the width of the spectrum. The model is effective for a developing and steady sea disturbance when the attenuation of the temporal correlation function can be approximated by an exponent. Numerical computations and experimental results for typical cases of sea disturbance are compared.Translated by Mikhail M. Trufanov.     

Radar studies of the distribution of the formation zones of the first radar echo of hail clouds

The results of studying the regions of hail-cell formation in the North Caucasus are considered. The optimal range of the underlying surface heights for their generation is determined based on an analysis of 392 hail cells. It is shown that the majority of hail cells are formed in the zone where the heights of the underlying surface vary from 900 to 2400 m. The most favorable conditions for the formation of hail clouds are recorded in the northern slopes of the Skalistyi (Rocky) ridge. This region accumulates the main maxima of the frequency of first radar echo recording. The second group of the frequency maxima is located over the Pastbishchnyi (Pasturable) and the Lesistyi (Woody) ridges. The generalized scheme for the region under study is constructed of three zones of generation of the first radar echo of the hail cells. It is shown that approximately 70% of hail clouds are formed over submontane and mountainous regions in the central North Caucasus (zones 2 and 3). The directions of motion of hail cells are quantified for each identified zone.     

入海河口生态预警监测站设立意义浅析

入海河口是河流和海洋生态系统的过渡带,陆源生态敏感因素入海将极大地影响近岸海域的生态状况。因此,入海生态敏感因素监测是海岸带生态保护和生态防灾减灾的重要基础,也是促进海洋经济可持续发展的关键一环。然而,当前我国入海河口生态预警监测系统的建立尚处于起步阶段,与发达国家之间还存在较大差距。文章从入海河口生态状况对海域生态系统健康的影响入手,总结了国内外入海河口海洋生态预警监测技术的发展历程、建设情况和应用方向,探讨了建设入海河口生态预警监测站的生态意义和系统发展方向。     

基于 GIS 的富钴结壳资源量计算系统开发

富钴结壳资源量计算和资源评价是大洋富钴结壳矿区圈定工作的重要内容之一。阐述了基于GIS组件MO构建富钴结壳资源量计算系统的主要功能模块组成和设计思路。该系统利用VC采取面向对象的方法编程,设计开发了富钴结壳资源量计算评价程序,实现了地质块段法等多种计算方法。该系统吸纳了资源评价和矿区圈定中水深、丰度、品位和坡度等几个重要评价指标,可方便地实现钴结壳资源量计算,为大洋富钴结壳矿区圈定和矿产资源开发提供依据和参考。     

Numerical experiments on estimating the accuracy of the methods of solution of the Kalman smoothing problems

The model numerical experiments on estimating the accuracy of two methods for solving the problem of Kalman smoothing, both iteration and precise, are described on the basis of a simple equation for the passive admixture transport. Some quantitative estimations are given.Translated by Mikhail M. Trufanov.     

Field studies of the motion of sediments in the coastal zone of the sea

We present the results of measurements carried out with the help of the “Donnaya Stantsiya” complex of equipment in the coastal zone of the Crimean shelf near Evpatoriya and near the southeast end of the Kosa Tuzla Island. For the same intensity of winds in these regions, the intensities of waves and turbulence in the coastal zone near Evpatoriya are much higher and, hence, the fluxes of suspended sediments are more intense. The accumulated data are intended for the correction of the kinetic model used for the evaluation of the characteristics of the field of suspended sediments in the shallow-water areas.