Generation of long waves in a basin of variable depth in the process of formation of a region of perturbations of atmospheric pressure

We perform the numerical analysis of the long-wave response of the free surface of a fluid in a basin of variable depth to the formation of an anomaly of the baric field for a finite period of time. In numerical experiments, we use the distribution of depths typical of the south coast of the Crimea. We also study the dependence of the dynamics of the sea level in the zone of the baric anomaly and in the shelf zone on the space and time scales of local changes in the field of atmospheric pressure in the open part of the basin. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

Influence of the discharge of rivers on the formation of level of a closed sea

Within the framework of a two-layer model, we consider the process of, formation of livel in a closed basin under the action of a source with constant flow rate located on its boundary in the upper layer. The response of the level of the basin to the inflow of liquid is observed in the form of the baroclinic and barotropic modes. The baroclinic mode, has the form of an edge wave for which the deviation of level is positive for the upper layer and negative for the lower layer. The barotropic component of the level is almost spatially homogeneous and its intensity increases with time. The increase in the volume of the upper layer caused by the inflow of liquid on the boundary is almost completely attained in the barotropic mode. In the lower layer, the increase in the volume attained in the barotropic mode is completely compensated by the baroclinic edge wave. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

Thermal evolution of the lithosphere of buried structures of the deep-water basin of the Black Sea

The GALO system for basin modeling is applied for numerical reconstruction of the thermal history of the lithosphere of the Western Basin and the Shatsky and Andrusov rises in the Black Sea. The modeling showed that the variant of the thermal evolution of the lithosphere of the region that was used by us for the Eastern Basin in our previous study is also applicable to the thermal evolution of the lithosphere of various tectonically different structures of the deep-water part of the Black Sea. These structures include both the Western and Eastern basins of the sea characterized by a granite-free crust formed in the course of the back-arc spreading and the Shatsky and Andrusov rises with the continental type of crust. The proposed version of the lithosphere evolution in the deep-water part of the Black Sea implies the initial stage of quasi-rift heating in the Upper Cretaceous and the three-staged thermal activation of the plate in the Cenozoic accompanied by three successive stages of crustal thinning. The latter resulted in the gradual deepening of the sea down to the present-day depth of 2.2 km.     

Variability of the nutrient runoff of the rivers of the Arctic Basin

The spatiotemporal variability of the hydrochemical composition of the riverine runoff in nearmouth areas is presented using the example of selected rivers of the Arctic Basin. The temporal dynamics of the riverine nutrient runoff are mainly determined by the seasonal and interseasonal variations in the drainage basins. The spatial variations in the chemical composition of riverine waters in the near-mouth areas are mainly caused by the dynamics of the water flow and the river bed relief and, to a lesser degree, by biochemical processes. It is shown that the variations in the nutrient composition of the waters in near-mouth areas are comparable in magnitude to those at the river-sea geochemical barriers.     

Distribution of metal concentrations in sediments of the coastal zone of the Gulf of Riga and open part of the Baltic Sea

The comparison of spatial and temporal distribution of Hg, Cd, Pb, Cu, Ni, Zn, Mn and Fe concentrations in sediments from the Gulf of Riga and open Baltic Sea along the coastal zone is presented for the first time. There were considerable differences in Pb, Zn, Mn and Fe levels in sediment at various stations of the Gulf of Riga. A significant difference of Cd, Pb, Cu, Ni, Zn levels was found in sediments of various stations in the open Baltic coast. The amount of Cd, Pb, Cu, Ni, Zn and Fe levels also differed significantly in the sediments of the Gulf of Riga in different years. A considerable yearly difference in amount of Hg, Cd, Pb, Cu, Ni and Mn levels was found in sediments in the open Baltic coast. The essential highest values of Pb and Zn in coastal sediments of the open Baltic Sea are stated in comparison with the Gulf of Riga. The concentrations of other metals have only a tendency to be higher in coastal sediments of the open Baltic Sea in comparison with the Gulf of Riga. Natural and anthropogenic factors were proved to play an important role in determining resultant metals concentrations in the regions.     

Analysis of characteristics and mechanism of current system on the west coast of Guangdong of China in summer

On the basis of data of drifting bottles＇ tracks and the current measured in anchored stations, as well as temperature and salinity observed in cruise investigations and coastal stations, ADCP current data and AVHRR surface sea temperature （SST） data on the western coast of Guangdong, synthetic results of analysis showed that the coastal currents in the west of the mouth of the Zhujiang River were mainly westward in summer, which constituted the north branch of cyclonic gyre in the east of the Qiongzhou Straits. Part of its water flowed westward into the Beibu Gulf through the Qiongzhou Straits. The coastal current pattern was not identical with the traditional current system which flowed westward in the Qiongzhou Straits in winter and eastward in summer. The summertime＇s coastal current was always westward, maybe temporarily turning northeast only when the southwest wind was strong. The important characteristics of coastal current on the western coast of Guangdong, in the Qiongzhou Straits and in the north of the Beibu Gulf were analyzed and their mechanisms also were explained.     

台湾近海的温、盐垂直结构与t－S图解类型

本文根据我国台湾海洋工作者的调查分析资料，对台湾近海的温、盐垂直分布及ｔ－Ｓ图解特征进行分析，按其相似性特点进行归类和分型，并探讨它们的特点和异同之处。主要结果如下：１．冬、夏季台湾近海的温、盐垂直分布类型有５种，ｔ－Ｓ图解类型为９种。２．冬季台湾近海的水温垂直分布存在着一层、二层、三层结构，夏季多为三层结构；冬、夏季的盐度垂直分布为二层和三层结构。３．台湾西南、南和东北近海，ｔ－Ｓ图解类型复杂，出现多种类型交错。４．夏季台湾南端的猫鼻头、鹅銮鼻沿岸附近，其温、盐垂直分布皆出现上均匀层，此现象实属少见。     

海鸟系列CTD数据预处理分析

介绍了海鸟系列温盐深测量仪(CTD)原始数据预处理的方法和步骤,解释各个过程中的原理,根据规范和工作实际对处理过程中存在的问题进行分析,提出解决方案,针对资料的标准化提出建议和意见。     

Modeling of the propagation of transient waves of moderate steepness

A theoretical approach is applied to predict the propagation and transformation of nonlinear water waves. A semi-analytical solution was derived by applying an eigenfunction expansion method. The solution is applied to analyze the effect of wave frequencies and wave steepness on the propagation of nonlinear waves. The main attention is paid to the wave profile, the wave energy spectrum, and the changes of wave profile and energy spectrum due to the interaction of wave components in a wave train. The results show that for waves of low steepness the nonlinear wave effects and effects associated with the interaction of water waves in a wave train are of secondary importance. For waves of moderate steepness and steep waves the effects associated with the interactions between waves in a wave train are becoming significant and a train of initially sinusoidal waves may drastically change its form within a short distance from its original position. The evolution of wave components has substantial effects on the wave spectrum. A train of initially very narrow-banded waves changes its one-peak spectrum to a multi-peak one in a fairly short period of time. Laboratory experiments were conducted in a wave flume to verify theoretical approaches. The free-surface elevation recorded by a system of wave gauges was compared with the results provided by the semi-analytical solution. Theoretical results are in a fairly good agreement with experimental data. A reasonable agreement between theoretical results and experimental data is observed often even for relatively steep waves.     

Diagnostics of the mesoscale water exchange on the basis of statistical characteristics of the distribution of normalized radiance

A new approach is suggested for the diagnostics of manifestations of water exchange in the field of normalized radiance and automation of the analysis of digital images of the water surface. The approach is based on the application of a set of statistical characteristics of a radiance relief as an integral indication of local inhomogeneities in the water medium and provides for the estimate of these characteristics over small regions (frames) of the basin studied using multispectral information. Using the example of the SeaWiFS scanner data on the evolution of an eddy dipole in August 1998 in a study region with a size of 160 × 160 km in the northwestern part of the Black Sea, it was shown that the estimates of a number of statistical characteristics of spectrally different radiance reliefs found in the frames with a size of 40 × 40 km significantly depended on the presence of fragments of an eddy dipole or other structures in these frames. A set of such characteristics made possible reliable differentiation of radiance reliefs by the degree of randomness, by the orientation of the inhomogeneities that form the relief, and by other properties caused by the variability of the light scattering and light absorbing admixtures in the sea medium in the course of the water exchange. The approach does not require any preliminary information about the object of observations. It is promising in the basins with moderate water transparency and vertical inhomogeneity of the upper layer available for remote profiling.     

Numerical Study of the Generation and Propagation of Trigger Meanders of the Kuroshio South of Japan

We examine the processes underlying the generation and propagation of the small meander of the Kuroshio south of Japan which occurs prior to the transition from the non-large meander path to the large meander path. The study proceeds numerically by using a two-layer, flat-bottom, quasi-geostrophic inflow-outflow model which takes account of the coastal geometries of Kyushu, Nansei Islands, part of the East China Sea, and the Izu Ridge. The model successfully reproduces the observed generation and propagation features of what is called "trigger meander" until it passes by Cape Shiono-misaki; presumably because of the absence of the bottom topography, the applicability of the present numerical model becomes questionable after the trigger meander passes by Cape Shiono-misaki. The generation of the trigger meander off the south-eastern coast of Kyushu is shown to be associated with the increase in the supply of cyclonic vorticity by the enhanced current velocity in the upper layer along the southern coast of Kyushu where the no-slip boundary condition is employed. Thereafter, the trigger meander propagates eastward while inducing an anticyclone-cyclone-cyclone pair in the lower layer. The lower-layer cyclone induced in this way, in particular, plays a crucial role in intensifying the trigger meander trough via cross-stream advection in the upper layer; the intensified trigger meander trough then further amplifies the lower-layer cyclone. This joint evolution of the upper-layer meander trough and the lower-layer cyclone indicates that baroclinic instability is the dominant mechanism underlying the rapid amplification of the eastward propagating trigger meander.     

Specific features of the vertical distribution of elements of the main biogenic cycles in waters of the Northwest shelf of the Black Sea

We study specific features of the vertical distribution of elements of the main biogenic cycle in the upper layers of waters on the northwest shelf of the Black Sea in spring and autumn and the correlation between the specific features of the vertical distributions of hydrochemical and hydrological characteristics. It is shown that the location of the halocline always specifies the location of the chemocline, whereas the effect of the thermocline on the distribution of hydrochemical characteristics is ambiguous. The vertical distribution of the hydrochemical parameters can be homogeneous in the presence of the seasonal thermocline. At the same time, in its absence, one may observe significant vertical gradients in the distributions of hydrochemical characteristics inside the upper mixed layer.     

珠江口悬浮泥沙迁移数值模拟

建立了珠江口海域三维悬浮泥沙的非饱和输沙数学模型,并与珠江口三维水动力斜压模型耦合,对悬沙迁移分布进行了模拟。模型由4个点的逐时实测含沙量过程进行了验证。各点模拟含沙量与实测含沙量吻合较好,表层分布与同期珠江口悬沙分布遥感图像基本一致.模拟结果表明,珠江口海域悬沙分布分层明显,河口附近水域大多为底层含沙量大于表层,但在盐淡水交汇处出现中层含沙量最小的情况总体上,自各个口门输出的泥沙受沿岸流作用向西南万向输送明显。大多数河口落潮时相对涨潮时含沙量等值线外移,反映珠江口水域悬浮泥沙主要来自河流。     

Hierarchy of the models of classical mechanics of inhomogeneous fluids

The methods of perturbation theory and integral representations are used to analyze the general properties of a system of equations of the mechanics of inhomogeneous fluids including the equations of momentum, mass, and temperature transfer. We also consider various submodels of this system, including the reduced systems in which some kinetic coefficients are equal to zero and degenerate systems in which the variations of density or some other variables are neglected. We analyze both regularly perturbed and singularly perturbed solutions of the system. In the case of reduction or degeneration of solutions, the order of the system decreases. In this case, regularly perturbed solutions are preserved (with certain modifications) but the number of singularly perturbed components participating in the formation of the boundary layers on contact surfaces and their analogs in the bulk of the fluid, i.e., the elongated high-gradient interlayers, decreases. The interaction between all components of the currents is nonlinear, despite the fact that their characteristic scales are different.     

Velocities of motion of liquid particles under the floating ice cover in the case of propagation of periodic waves of finite amplitude

By using the velocity potential obtained by the method of multiscale asymptotic expansions to within the quantities of the third order of smallness, we study the dependences of the components of the velocity of motion of a homogeneous liquid under the floating ice cover on the thickness of the cover and its modulus of elasticity in the process of propagation of periodic waves of finite amplitude. It is shown that the presence of broken ice leads to a decrease in the moduli of components of the velocity of liquid particles and the phase delay of generated oscillations. The effect of the elasticity of ice becomes more pronounced as the wavelength of the initial harmonic decreases and manifests itself in the increase in the maximum values of the components of velocity and in the phase shift of oscillations in the direction of propagation of waves.     

鹿角珊瑚人工养殖的初步研究

为了探讨珊瑚人工养殖的基本条件和方法,分别在陆基水泥池中和海底珊瑚苗床上对3种鹿角珊瑚:粗野鹿角珊瑚(Acropora humilis)、霜鹿角珊瑚(Acropora pruinosa)和松枝鹿角珊瑚(Acropora brueggemanni)的人工养殖进行了实验。结果表明,这3种珊瑚可以在深圳市鹅公湾近岸海域的海底珊瑚苗床上常年生长;在水泥池中当水温低于14℃或高于28℃时珊瑚陆续死亡;这3种珊瑚的生长速度在适温范围内随着水温的升高而加快,最大月生长值是6.05 mm;光照对这3种珊瑚的生长有影响,直接的阳光照射会引起水泥池中珊瑚的死亡。     

舟山养殖海域承载力评价研究

海水养殖是舟山开发利用海洋的主要经济活动,也是舟山的传统特色产业之一。为促进舟山更好地发展海水养殖业,文章运用熵权TOPSIS模型,基于2006-2018年舟山海水养殖的相关数据,对舟山养殖海域承载力进行评价。研究结果表明：舟山养殖海域承载力总体呈上升趋势;养殖资源承载力呈波动上升趋势,与养殖海域承载力的变化趋势基本一致;养殖环境承载力的变化幅度较大,并与海水水质的变化趋势相吻合。     

Investigation of the mechanism of the long-term evolution of the carbon cycle in the ecosystem of the Sevastopol bay

We analyze the components of the carbon system of the Sevastopol bay waters and the balance of main sediment-forming substances using the data of field investigations in 1998–2008. The interannual variations of total inorganic carbon and the equilibrium partial pressure of carbon dioxide in the bay water are noted. An increase in the flux of carbon dioxide into the bay and in the content of organic carbon in bottom sediments is revealed, and an explanation of this phenomenon is given. The priority accumulation of organic carbon in the sediments of the bay is established. We assess the interannual variation in the relative abundances of organic and inorganic carbon as an index of the carbon cycle stability.     

Evolution of the slope of the buried depression of the Black Sea

The first data on the temporal evolution of the slope of the buried depression of the Black Sea are obtained. The sharp change in the rate of the decrease in the slope steepness that occurred in the Late Miocene-Pliocene time reflects a reorientation of the vector of mutual movement and a related intensification of the collision between the Arabian and Eurasian lithospheric plates.