Analytical study of the effect of the geometrical parameters during the interaction of regular wave-horizontal plate-current

The present work is an analytical study of the influence of geometrical parameters, such as length, thickness and immersion of the plate, on the reflection coefficient of a regular wave for an immersed horizontal plate in the presence of a uniform current with the same direction as the propagation of the incident regular wave. This study was performed using the linearized potential theory with the evanescent modes while searching for complex roots to the dispersion equation that are neither pure real nor pure imaginary. The results show that the effects of the immersion and the relative length on the reflection coefficient of the plate are accentuated by the presence of the current, whereas the plate thickness practically does not have an effect if it is relatively small.     

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.     

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.     

Upwelling into the thermocline of the Pacific Ocean

The established “island rule” and the recently introduced “separation formula” are combined to yield an analytical expression for the total upwelling into the thermocline in the Pacific. The combination of the two is achieved with the use of a hybrid model containing a stratified upper layer, a thick (slowly moving) homogenous intermediate layer and an inert lower layer. Both the upper and the intermediate layers are subject to diabatic cooling and heating (which need not be specified) and there is an exchange of mass between the two active layers. An attempt is made to examine the above analytical (hybrid) model numerically. Ideally, this should be done with a complete two-and-a-half layer model (with upwelling and downwelling), but such a model is much too complex for process-oriented studies (due to the required parameterization of vertical mixing). Consequently, we focus our attention on verifying that the separation formula and the island rule are consistent with each other in a much simpler, layer-and-a-half model (without upwelling). We first verified that the new “separation formula” provides a reasonable estimate of the wind-induced transport in an island-free basin. We then compare the wind-induced transport predicted by the separation formula and the island rule in an idealized basin containing an island. We show that in these idealized situations the two methods give results that are consistent with each other and the numerics. We then turned to an application of the (hybrid) two-and-a-half layer model to the Pacific where, in contrast to the idealized layer-and-a-half models (where the two methods address the same water mass), the two methods address two different water masses. While the separation formula addresses only thermocline water (σ_θ<26.20), the island rule addresses all the water down to 27.5σ_θ (i.e., both the upper and intermediate layer). This is why the application of the two methods to the Pacific gives two different results — an application of the formula gives zero warm water transport whereas an application of the island rule gives 16 Sv. Namely, the difference between the amount predicted by the island rule (16 Sv) and the amount predicted by the separation formula (zero) enters the Pacific as intermediate water and is then somehow upwelled into the thermocline. The upwelling should take place north of the southern western boundary currents separation (40°S).     

On the nature of the Khvalynian transgression of the Caspian Sea

This paper presents a reconsideration of the hypothesis that the Khvalynian transgression of the Caspian Sea resulted from an abundant inflow of meltwaters from Siberian proglacial lakes through the Aral Sea and via the Uzboi channel and may be considered as a prototype of Noah’s Flood. A thorough analysis of the evidence suggested by the proponents of this hypothesis revealed a lack of factual substantiation; there are no facts indicating the existence of the Aral flow-through lake or of the Siberian proglacial water supply to the Caspian Sea. The spatial distribution of the mollusk fauna provides no support for the view that the Khvalynian transgression was essentially influenced by thawing of ice sheets on the Russian Plain. The Khvalynian transgression, though geologically short-term, could not be an analogue of Noah’s catastrophic flood. The sea level rose at a rate of a few centimeters per year for a few thousand years; this interval covered the lifetimes of many generations of the Caspian coast inhabitants. The Khvalynian water overflowing via the Manych Strait into the Pontian basin provided an even smaller influence. It resulted in flooding of the middle part of the Black Sea shelf, in a 30-m sea level rise, and in a water salinity increase by 5‰.     

Educating for the governance of coastal ecosystems: the dimensions of the challenge

There is a fundamental shift in how the problems confronting a practicing coastal manager are being defined. Coastal zone management began as an expression of an environmental protection strategy and has evolved into a promising vehicle for progressing towards more sustainable forms of development. The contemporary practice of coastal management requires integrating within a curriculum a diverse mix of knowledge and skills that emphasize the two defining features of adaptive management. These are a governance process rooted in the principles of participatory democracy and the application of the scientific principles that can produce reliable knowledge.     

Long-term variations of the location of the upper boundary of the hydrogen-sulphide zone in the Black Sea

We analyze the dependence of climatic variations of the location of the upper boundary of the hydrogen-sulphide zone in the Black Sea on the variations of the sea level and various types of atmospheric circulation (according to A.A. Girs). It is discovered that the level of correlation between the indicated parameters is high and that the corresponding plots are in good qualitative agreement. The accumulated results enable us to make an assumption that there exists an 80–100-yr cycle of variation of all analyzed parameters and that the long-term variations of the location of the upper boundary of the hydrogen-sulphide zone can be regarded as a manifestation of global climatic variations. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

许氏平鲉消化道的组织化学研究

运用组化方法对许氏平消化道碱性磷酸酶、酸性磷酸酶、羧酸酯酶和粘液物质进行了定位及半定量研究。发现幽门盲囊和肠上皮细胞顶端胞质和纹状缘具碱性磷酸酶活性 ;胃粘膜上皮细胞核上方胞质、幽门盲囊及肠上皮细胞顶端胞质中检测到酸性磷酸酶活性 ;在胃贲门部和盲囊部、幽门盲囊以及肠的上皮细胞内还检测到羧酸酯酶活性。整个消化道的粘膜层中存在许多粘液细胞。食道上皮含大量酸性粘液细胞 ,胃上皮细胞均含有中性粘液 ,而肠道由前向后中性粘液物质逐渐减少 ,酸性粘液物质逐渐增多。研究结果表明许氏平食道和直肠有润滑和微弱的吸收作用 ,胃有消化脂类和吸收二糖及短链脂肪的功能 ;幽门盲囊有较强的吸收脂类的功能 ;前肠、中肠和后肠有活跃的细胞内消化和吸收功能     

Aspects of the Reproductive Activity of Penaeus semisulcatus de Haan along the Southeastern Coast of the Mediterranean

Abstract. Reproductive parameters of the females of Penaeus semisulcatus regarding the process of ovary maturation, the degree of synchronization of the ova maturation stage within an ovary, the correlation between female length and both maturity and fecundity, as well as the relationship between moulting, copulation and ovarian maturity stage were investigated.
The seasonal and spatial pattern of the reproduction of the female population of P. semisulcatus along the southeastern coast of the Mediterranean was determined.
Average ova diameter, morphological appearance of the ova, presence of sperm, characteristics of the spermatophore, and hardness of the cuticle were used in order to study the above parameters.     

Paleo-bathymetry of the northern North Atlantic and consequences for the opening of the Fram Strait

In the past decade, the geophysical database in the northern North Atlantic and central Arctic Ocean constantly grew. Though far from being complete, the information from new aeromagnetic and seismic data north of the Jan Mayen Fracture Zone and in the Arctic Ocean, in combination with existing compiled geological and geophysical data, is used to produce paleo-bathymetric maps for several Cenozoic time intervals. This paleo-bathymetric model provides evidence for an initial deep-water exchange through the Fram Strait starting around 17 Ma. Furthermore, the model suggests that crustal rifting prior to initial seafloor spreading might have facilitated an earlier deep-water connection. This confirms that the paleo-topography of the Yermak Plateau played an important role in allowing at least the exchange of shallow water between the northern North Atlantic and the Arctic Ocean before the opening of the deep-water Fram Strait gateway. In the south of the research area the paleo-bathymetric model indicates that the first possibility for a deep-water overflow from the Norwegian-Greenland Sea to the North Atlantic could have been between 15 and 20 Ma.     

Seismic stratigraphy and structure of the area to the southeast of the trobriand platform

The area to the southeast of the Trobriand Platform contains an easterly continuation of the Oligocene to Quaternary Cape Vogel Basin (CVB). Within this area, three major seismic sequences are recognized: sea bed-A, A–B, and B–D. The latter sequence occurs within a depocenter with approximately 3,200 m of sediment. The A–B and B–D sequences were faulted and gently folded in Late Miocene times.To the south and southeast of this depocenter the CVB has been truncated by the Pliocene opening of the Woodlark Basin, an active westward-propagating spreading system.     

日本南部黑潮与黑潮延伸体路径状态关联性的定量分析

日本南部黑潮存在多种路径模态:近岸非大弯曲路径、离岸非大弯曲路径和大弯曲路径。黑潮延伸体的路径存在两种典型模态:收缩态和伸展态。从地理位置看, 日本南部黑潮和黑潮延伸体是相邻的, 但它们的路径状态是否存在关联一直存在争议。本文基于卫星观测的海表高度资料和长期的海洋高分辨率再分析资料, 对日本南部黑潮和黑潮延伸体路径状态之间的关联性进行定量分析, 结果表明:日本南部黑潮和黑潮延伸体的路径状态存在一定的关联。当日本南部黑潮处于近岸非大弯曲和大弯曲路径时, 黑潮延伸体主要处于伸展态; 当日本南部黑潮处于离岸非大弯曲时, 黑潮延伸体处于伸展态和收缩态的比例相当。进一步分析表明, 黑潮流轴处于伊豆海脊的位置部分决定了上述关系, 可能存在其他因素调制了两者的关联性。     

长江河口北槽水沙过程对航道整治工程的响应

北槽大型航道整治工程确定了南北槽分汊口分流界线, 阻碍了北槽和邻近滩槽的水沙自由交换过程, 使北槽水沙动力过程发生调整。基于工程前后北槽主槽纵向同步水沙观测数据的统计分析表明:入口段落潮优势显著减弱;上段枯季时落潮优势显著减弱, 而洪季时落潮优势有所增强;中段(弯曲段拐点附近)落潮优势略有减弱;下段落潮优势明显加强。北槽主槽水沙纵向输移机制分析表明:欧拉余流、潮泵作用、斯托克斯效应和垂向环流为悬沙输移的主要驱动力, 其中欧拉余流输沙指向海, 斯托克斯输沙和垂向环流输沙指向陆, 而潮泵输沙随着季节而变化。洪季, 欧拉余流输沙和潮泵输沙在工程前后的变化使大潮期河床冲淤由中段和下段普遍落淤转化为中上段集中落淤。枯季, 工程前后稳定的潮流辐散输沙作用使大潮期河床以冲刷为主, 但工程后在入口段和上段潮泵的向上游输沙占优势, 使悬沙在入口段落淤。     

Organic geochemical study of the Upper Kimmeridge Clay of the Dorset type area

Results are presented from an organic geochemical investigation of a suite of rock samples taken from the Upper Kimmeridge Clay near Kimmeridge, Dorset. All samples contain immature organic matter of marine origin, although one horizon, the Whitestone Band, contains an additional secondary input of partially biodegraded mature hydrocarbons, due to an oil seepage of unknown origin. With the exception of increased relative abundances of 4-methylsteroidal hydrocarbons in the more organic-rich samples, the immature molecular distributions are very similar, suggesting a consistent source of organic matter. The results are in agreement with the palaeoenvironmental model proposed by Tyson et al. (1979) for the deposition of the Kimmeridge Clay, where the different lithologies are controlled by a fluctuating oxic/anoxic boundary, with only the organic-poor mudstones being deposited in relatively oxygenated waters.     

Calculation of the initial elevation at the tsunami source using analytical solutions

We have obtained an analytical solution to the problem of determining the initial elevation at the tsunami source, which was formed by small residual deformations of a flat sloping bottom. This solution, which is newly derived, is compared with the known analytical solution of an equivalent problem over a horizontal bottom. It is shown that applying an analytical solution over a horizontal bottom for calculating the initial perturbations in the sources of realistic tsunami provides sufficient accuracy.     

Estimation of the buoyancy profile on the dispersion characteristics of internal waves

In this paper an interaction method is proposed for estimating the buoyancy frequency as a function of depth based on the frequency dependence of wave numbers of internal normal waves. Examples are given of the numerical reconstruction of buoyancy frequency profiles demonstrating convergence of the algorithm. An iterative scheme for the solution of the given problem with an expanded convergence area is obtained on the basis of iteration by stages.Translated by M M. Trufanov.     

Mesoscale Variability of the Ocean in the Northern Part of the Weddell Sea

Oceanology - Results of a mesoscale survey in the Powell Basin in the northern part of the Weddell Sea are analyzed. The survey included 24 CTD casts (6 × 4) with an interval of six nautical...     

Thickening of the oceanic layer in the Pacific Ocean

A statistical analysis of published seismic refraction results in the Pacific Ocean confirms the existence of a progressive thickening of the oceanic layer with age, following an inverse exponential law. There is no strong indication in the Pacific data of an increase in the thickness of layer 2 with decreasing spreading rate.Contribution No. 93 of the Département Scientifique of the Centre Océanologique de Bretagne, B.P. 337, 29200, Brest, France.     

On the peculiarity of the sound channel on the shelf of the North-European basin

Analysis of the sections traversing the polar hydrological front on the shelf of the North-European basin has enabled us to reveal the areas limited by closed isotaches of the sound velocity existing in the interfrontal zone at depths of 50–150 m. These areas represent the closed waveguide which has the property of an underwater sound channel.Translated by Mikhail M. Trufanov.     

On the monitoring of the thermal state of the upper ocean

This paper discusses some problems related to the development of systems of global monitoring of the sea surface temperature (SST). The characteristics of the operational SST data are considered and estimations of their accuracy are given. The applications of varoous models to the computation of SST in relation to the development of an oceanographic data assimilation system are reviewed briefly.Translated by Mikhail M. Trufanov.