共查询到20条相似文献，搜索用时 15 毫秒
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2.
We discuss specific features of the space distribution and the processes of assimilation and oxidation of the dissolved and emulsified fractions of oil hydrocarbons in Black-Sea waters and study the methods of parametrization of these processes proposed in the literature. We develop a procedure of parametrization of the processes of degradation of oil hydrocarbons taking into account their complex chemical compositions, characteristics of chemical and microbiological processes, and temperature dependences of these processes and perform numerical experiments aimed at the reconstruction of the seasonal variations of the large-scale space structure of the distribution of oil hydrocarbons in the aerobic zone of the Black Sea. 相似文献
3.
We analyze the statistical structure of the data of remote sensing of the fields of surface temperature and the concentration
of chlorophyll in the northwest part of the Black Sea with an aim to apply the method of optimal interpolation to the restoration
of the maps of these fields according to the restricted amounts of data. We determine the scales of smoothing for the selection
of the random components of the fields and estimate their difference from the statistical model uniform and isotropic over
the space correlation coefficients. The functions of spectral densities are constructed along various sections and the best
intervals of discretization of the fields required to perform the optimal interpolation with given accuracy are determined.
It is shown that the construction of the maps of fields under the conditions of controlled accuracy of reconstruction of their
values remains possible even if the amounts of the input satellite data are significantly decreased. We consider a procedure
of evaluation of the best possible amounts of data required for the use of the method of optimal interpolation. Some examples
of application of this procedure to the data of remote sensing of the fields of surface temperature and the concentration
of chlorophyll are presented. 相似文献
4.
Reconstruction of the surface temperature fields according to the fragmentary data of remote sensing
E. F. Vasechkina 《Physical Oceanography》2011,21(3):195-210
We propose a gap-filling method for the data of remote sensing of the hydrophysical and biological characteristics of the
water surface. The proposed method of reconstruction is based on the representation of the fields of surface characteristics
as the sums of certain numbers of empirical orthogonal functions (EOF) making the largest contributions to the total variance
of the field. According to the fragmentary data obtained as a result of processing of the satellite images for the summer
season, we construct estimates of the mean field and of the four-dimensional space covariance function of the surface temperature
of the Black Sea. The coefficients of expansion are computed by the method of least squares or determined with the help of
a genetic searching algorithm. The results of numerical experiments show that the proposed method is quite promising for applications
in the problems of gap filling in the available satellite data. 相似文献
5.
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. 相似文献
6.
SHI Hongda SUN Fu
Lecturer 《中国海洋工程》1999,(2)
The rate of change of wave surface elevation is of much importance in ocean engineering,es-pecially for the determination of the limitation of wave breaking.This paper gives a kind of joint distribu-tion of wave periods and the rate of change of wave surface elevation by means of calculation of the two-or-der to four-order moment of the frequency spectrum based on the linear wave theory.For the first time,the distribution density function of wave periods determined by peaks is provided,and the conclusion isdrawn that the rate of change of wave surface elevation obeys the Rayleigh distribution. 相似文献
7.
We perform the numerical analysis of the process of propagation of long waves in the northwest part of the Black Sea and consider
ten possible zones of the seismic generation of tsunamis. The numerical analysis is performed on a grid with steps of 500 m.
It is shown that the location of the tsunami source significantly affects the distribution of the heights of waves along the
coast. As a rule, the most intense waves are formed in the closest part of the coast. The earthquakes in the South-Coast seismic
zone do not lead to the formation of tsunamis in the west part of the sea. Only strong earthquakes in the northwest part of
the sea can be responsible for noticeable oscillations of the Black-Sea level. The period of tsunamis near Odessa is close
to 1 h and depends on the magnitude of the earthquake. In the region of Sevastopol, this period is 2--3 times smaller. In
the major part of the coastal points, the extreme elevations and lowerings of the sea level do not exceed (in modulus) the
initial displacements of the sea surface at the source of tsunamis. An intensification of waves emitted from the zones of
generation located in the deeper part of the investigated region was observed for some parts of the Romanian coast and the
west coast of Crimea. As the magnitude of the earthquake increases, the intensification of waves near the coast becomes more
pronounced. 相似文献
8.
D. V. Alekseev V. A. Ivanov E. V. Ivancha V. V. Fomin L. V. Cherkesov 《Physical Oceanography》2005,15(6):336-345
By the method of mathematical simulation, we study the evolution of local discharges of pollutants on the northwest shelf
of the Black Sea induced by the motion of a cyclone. We use the nonlinear equations of motion of a homogeneous viscous fluid
in the hydrostatic approximation and the equation of turbulent diffusion. A cyclonic formation is represented by a moving
axisymmetric area of low pressures. The discharges of pollutants are caused by the action of instantaneous sources located
on the sea surface. We perform the analysis of dependences of the paths of motion of polluted regions, the periods of their
dissipation, and the depths of penetration of pollutants on the bottom topography and the intensity of diffusion processes.
__________
Translated from Morskoi Gidrofizicheskii Zhurnal, No. 6, pp. 17–27, November–December, 2005. 相似文献
9.
We propose a new information technology aimed at modeling of biochemical processes in marine ecosystems and based on the use of logical operators of control (intelligent agents) in the dynamic equations of the models. We develop a conceptual model of an ecosystem reflecting the interaction of 17 biochemical processes and 5 external factors. The equations of the model are obtained by the method of adaptive balance of causes (ABC method), which enables one to simulate complex scenarios of the processes running in the investigated systems and guarantees the possibility of robust calculations. Some examples of the behavior of ecosystems under the conditions of deficiency of oxygen caused by the action of natural and anthropogenic factors are presented. As a result, it is possible to make a conclusion that the combined application of the ABC-equations and intelligent agents of control in models of marine ecosystems is quite promising. 相似文献
10.
As a result of the field studies conducted in 2010 of the spatial and temporal variability of the granulometric composition
of the bottom and beach deposits of the southern part of the Anapa bay bar, the tendency of a decrease in the average size
of the particles under the southward flow of the deposits of the coastal zone was revealed. The comparison of the data obtained
in 1949, 1979, and 2010 shows that the average diameter of the particles in the deposits of the underwater slope also gradually
decreases over the time. It was established that, with the decreasing of the particle sizes down to 0.1 mm, their nonrecoverable
deposition to a depth of more than 7 m increases. Since, in the southern edge of the Anapa bay bar, over 70% of the bottom
and about 60% of the beach deposits are represented by fractions smaller 0.16 mm, at this site the mass deposition of the
sand material to a depth occurs. Based on the data obtained, the particle size of the sandy material recommended for the restoration
of the beaches of the southern part of the Anapa bay bar was determined. 相似文献
11.
The results of theoretical studies of fracture lines in the ice floes of the Gulf of Ob as a function of the coefficient of internal sliding are presented in this paper. An estimate of the fractal dimensions of the emerging topological structures and the results of the calculation of stresses in the ice cover of the Gulf of Ob are presented as functions of different directions of external forcing caused by the joint action of winds and currents on the ice. The geographical locations of the zones of possible loads are shown, together with the estimates of the hummock sizes in the zones of the maximal compression of the ice floes in the Gulf of Ob. 相似文献
12.
LU Xiaoxi SONG Jinming LI Xuegang YUAN Huamao ZHAN Tianrong LI Ning GAO Xuelu 《海洋学报(英文版)》2004,23(3):473-482
The distributions of different forms of nitrogen in the surface sediments of the southern Huanghai Sea are different and affected by various factors. The contents of IEF-N, SOEF-N and TN gradually decrease eastward, and those of SAEF-N northward, while those of WAEF-N westward. Around the seaport of the old Huanghe (Yellow) River, the contents of both SOEF-N and TN are the highest. Among all the factors, the content of fine sediment is the predominant factor to affect the distributions of different forms of nitrogen. The contents of IEF-N, SOEF-N, and TN have visibly positive correlation with the content of f‘me sediments, and the correlative coefficient is 0.68, 0.58 and 0.71 respectively, showing that the contents of the three forms of nitrogen increase with those of f-me sediments. The content of WAEF-N is related to that of fine sediments to a certain extent, with a correlative coefficient of 0.35; while the content of SAEF-N is not related to that of fine sediments, showing that the content of SAEF-N is not controlled by fine grain-size fractions of sediments. In addition, the distributions of different forms of nitrogen are also interacted one another, and the contents of IEF-N and SOEF-N are obviously affected by TN, while those of inorganic nitrogen (WAEF-N, SAEF-N and IEF-N) are not affected by SOEF-N and TN obviously, although they are interacted each other. 相似文献
13.
A plane problem of generation of barotropic seiches in a bounded rotating basin by traveling atmospheric fronts is studied
within the framework of the linear theory of long waves. The front is characterized by disturbances of the baric field and
the corresponding field of tangential wind stresses. We deduce the modified Ackerblom formulas for the wind stresses according
to the given anomalies of atmospheric pressure in which the uniform transport of disturbances of the baric field is taken
into account. We perform the numerical analyses of the dependences of the amplitudes of oscillations of fluid in the basin
on the parameters of the atmospheric front and the choice of the formulas for the tangential wind stresses. The influence
of the wind stresses leads to significant quantitative and qualitative changes in the oscillations of fluid in the basin as
compared with the case of pure baric action. 相似文献
14.
15.
Flocculation process of fine-grained sediments by the combined effect of salinity and humus in the Changjiang Estuary 总被引：1，自引：0，他引：1
1 IntroductionThe flocculation of fine-grained particles is onof the main reasons for the estuarine depositionWith the combination of salt water and freshwaterfine-grained particles in estuaries will experiencdrastic changes: flocculation, settlement, res… 相似文献
16.
陆地卫星相片的海岸带解译 总被引：2，自引：1，他引：2
海岸带是海洋与陆地交互作用的地带。海岸带的地貌和水文特征按潮汐海面可分为三带:高潮位以上的海滨,包括沿岸堤平原和海蚀阶地等,它们是古海洋作用的遗迹,一般不受现代海洋动力的影响,高潮位与低潮位之间的潮间带,它们随涨落潮而周期性地被淹;以及低潮位以下一直到波浪作用极限深度的水下岸坡,包括浅海和泻湖水域,属于水下环境。 相似文献
17.
We study the regularities of annual variations in the concentration of oxygen and the degree of saturation of waters in the
Sevastopol Bay with oxygen in 1998–2009. The three-dimensional specific features of seasonal variations in the distribution
of oxygen in waters of the Sevastopol Bay are revealed. Two periods can be separated in the annual course of the content of
oxygen in the surface layers of waters in all parts of the bay: the period of supersaturation in March–September and the period
of undersaturation in October–February. In the bottom layer of waters in all parts of the bay, we observe the undersaturation
of waters with oxygen for the whole year. 相似文献
18.
本文根据三峡工程对长江龙口站水位影响的预测结果，通过对立龙口站与四湖地区水位站，以及与龙口地区地下水位的相关关系，进而研究三峡工程对四湖地区水情的影响。 相似文献
19.
We demonstrate the importance of investigation of the behavior of methane as a source of energy and an element of the Black-Sea
ecosystem affecting the global behavior of the climate. We describe the genesis of methane and the processes of its aerobic
and anaerobic oxidation. An especially important biogeochemical and ecological role is played by the anaerobic oxidation of
methane guaranteeing the formation of its effective sink inside the anaerobic zone and preventing its penetration into the
atmosphere as a greenhouse gas. On the basis of the analysis of the experimental data available from the literature, we also
discuss the principal regularities of the distribution of concentration of methane and its flows. It is shown that the formation
of methane hydrates at the bottom in the abyssal part of the Black Sea and the events of jet gas release on the periphery
of the basin can be regarded as the components of a single global process of gas release from the bottom of the Black Sea.
We present estimates of the components of methane budget in the Black Sea. The results of simulation of the dynamics of methane
bubbles and the processes of their gas exchange with the medium are analyzed. The data of hydroacoustic measurements are used
to evaluate the distribution of methane bubbles in sizes and the mass transfer of methane through the ocean–atmosphere interface.
Finally, we consider the methods of mathematical simulation of the distribution of methane in the ecosystem of the Black Sea.
Translated from Morskoi Gidrofizicheskii Zhurnal, No. 5, pp. 40–56, September–October, 2008. 相似文献
20.
皱纹盘鲍主要器官的亚显微结构 总被引：2，自引：0，他引：2
对皱纹盘鲍的胃、直肠、消化腺、肾、鳃、心脏、外套膜、足等器官的亚显微结构进行了研究。结果表明 :(1 )各消化器官的组织结构中富含酶原颗粒和分泌颗粒 ,这些颗粒具有消化和抗病的功能 ;(2 )鳃和心肌的组织结构中富含线粒体 ,这与其活动量大密切相关 ;(3 )外套膜的组织结构中富含分泌颗粒 ,这些颗粒物质参与贝壳的形成和体液免疫 ;(4)肾实质中静脉呈网状分布 ,这与体液的有效过滤有关 ;(5 )腹足的肌纤维成束 ,并形成三维的网状结构 ,以适应匍匐与吸附的生活方式 相似文献