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1.
We discuss the influence of hydrophysical and biological-chemical processes on the distribution of dissolved oxygen in waters of the Sevastopol bay in various seasons. In the winter period, against the background of low rates of biological-chemical processes, the hydrophysical processes provide the homogeneous distributions of temperature and oxygen. In summer, the hydrophysical processes remain dominant, but the influence of biological-chemical processes becomes noticeable. In the autumn period, the vertical distribution of oxygen is strongly affected by biological-chemical processes.  相似文献   

2.
This report presents a new analysis of the results of two hydrochemical surveys over the Ob Bay in 2010 performed by the Institute of Fisheries and Oceanography (VNIRO) and the Institute of Oceanology (IO RAS). The unique world feature of the Ob River-Ob Bay system is shown. The water volume in the bay exceeds the average annual runoff of the Ob River, being somewhat under the total runoff of all the inflowing rivers. Because of this, the complete renovation of the waters in the bay requires a long time. The within-year distribution of the runoff is characterized by both the flood waters and those of the Ob River winter runoff characterized by much different hydrochemical parameters registered even in the course of summer surveys in the bay. This fact, but not the biological transformation of the waters, as assumed previously, is the primary cause of the variability of the water composition in the bay. The summer waters of the Ob River reach the sea-ward boundary of the bay only in the next spring, enter the Kara Sea with the spring flood, and form lenses of desalinated waters in the sea. The autumn expeditions by the IO RAS found that the waters in the lenses were quite similar to the autumn waters in the bay, although these were the Ob River waters of different years, which was disregarded formerly.  相似文献   

3.
The thermohaline and hydrochemical characteristics of the Lena River’s estuarine zone were investigated in the Buor-Khaya Bay and the southeastern Laptev Sea in September of 2005. A tongue of river water with high nutrient content and increased turbidity was identified in the bay. It is shown that the two-layer structure in the bay is disturbed by warm freshwater lenses. The strong vertical stratification in the shelf zone results in sharply contrasting characteristics of the surface and bottom waters. It is established that the concentrations of biogenic elements regularly change depending on the thermohaline characteristics of the waters and their stratification degree. Stagnant bottom waters with low dissolved oxygen contents and high concentrations of phosphates, nitrates, and ammonium are recorded in the eastern part of the bay. The bottom waters have different hydrochemical characteristics due to their different origin.  相似文献   

4.
Distribution of Sea of Azov water on the Crimean shelf and its penetration into the Gulf of Feodosia result in significant changes in the hydrophysical and hydrochemical structure of the water area. This inflow is also estimated as a major source of anthropogenic pollution in the region. At the same time, the Gulf of Feodosia is one of the least investigated areas of Russian Black Sea coast. The paper focuses on the hydrophysical structure of the Gulf of Feodosia and southeastern part of the Crimean shelf. The results of a field survey in May 2015 made it possible to reveal the presence of Sea of Azov water in the gulf and describe its thermohaline properties, along with the character of distribution. It is shown that contamination of Sea of Azov water in the gulf could mostly be determined by the synoptic dynamic processes in the area rather than by the seasonal variability of discharge in the Kerch Strait. The possible influence of the distribution of Sea of Azov water on the formation of cyclonic gyres in the coastal area of the region is indirectly confirmed by in situ measurements.  相似文献   

5.
根据1979年的胶州湾水域调查资料,分析了重金属铬在胶州湾水域的分布、迁移和季节变化。研究结果表明;春季,胶州湾水城铬污染较轻,大部分海域水质状况较好,而到夏季没有受到污染。在时空分布上,春季,铬污染形成了明显的梯度,由东北向西南方向递减,从112.3μg/L降低到0.2μg/L。夏季,铬的水平分布比较均匀,表层水体铬的含量较低,范围在0.10~1.40μg/L之间波动。因此认为,1979年整个胶州湾水域的重金属铬属于面污染源。而且,当铬进入胶州湾海域后,很快吸附在水体中的悬浮颗粒上,并被水流较快地带离胶州湾水城,几乎没有在胶州湾水域表、底层留下污染痕迹。  相似文献   

6.
The paper discusses mathematical simulation of intensive coastal upwelling observed in the northeastern part of the Black Sea in the water area of the hydrophysical test site of the Shirshov Institute of Oceanology, Russian Academy of Sciences, in September 2013. The simulation was carried out with the MIKE 21/3 Coupled Model FM combined hydrodynamic model of the Danish Hydraulics Institute (DHI). The calculation results are compared with the data of direct instrumental observations carried out in the IO RAS hydrophysical survey area. The essential role of surface wind waves in the formation of the observed temperature profiles is demonstrated, as well as the necessity of taking it into account when considering peculiarities in the vertical circulation of coastal waters.  相似文献   

7.
On the basis of the data of the complex oceanographic experiment carried out in the course of the second Ukrainian Antarctic expedition in March 1998, we study the structure and kinematics of waters in the region of the archipelago of Argentine Islands. The regularities of thermohaline stratification of waters are discovered. We determine the most important environmental parameters premoting the variability of hydrophysical fields on time scales varying from several days up to a week, analyse the data of actual observations over the currents, and estimate the relative contribtions of diurnal and semidiurnal tidal waves to the total dispersion of hydrophysical parameters of the environment. The residual currents are filtered out. We propose a hypothesis about the mechanism of their formation. Various types of tidal currents are revealed and the directions of propagation of diurnal and semidiurnal tidal waves are determined. Translated by Peter V. Malyshev and Dmitry V. Malyshev  相似文献   

8.
In September 2006, field studies were performed in the course of the seventh regular expedition of the Shirshov Institute of Oceanology of the Russian Academy of Sciences within the frameworks of the program for multidisciplinary studies and monitoring of the condition of the hydrophysical, hydrochemical, and hydrobiological systems of the Aral Sea under the anthropogenic crisis. This program has been implemented together with a series of scientific institutions of Uzbekistan and Kazakhstan starting in 2002. The results of the previous expeditions have been presented earlier in a series of publications (for example, [3–6, 12, 13]).  相似文献   

9.
Extractable organic copper using C18 Sep-Pak cartridges was investigated in seawater after laboratory experiment showed that the (C18 Sep-Pak) cartridges were reliable, in open and coastal waters with normal levels of dissolved organic carbon, for the separation of a specific fraction of organo-copper complexes.Given that the Sep-Pak cartridges retain the hydrophobic fraction of the dissolved organic matter, this extraction technique was applied for studying the characteristics of this particular hydrophobic dissolved organic copper fraction (hDOCu) in the north-western Mediterranean waters. Surface distribution of hDOC is influenced by organic matter input from the river Rhone and its estuary as well as the physical processes affecting the primary productivity such as coastal upwelling. By correlating hDOCu concentrations with total dissolved copper and other hydrochemical data such as salinity and dissolved organic carbon, it was possible to examine the behaviour of hDOCu in the water masses of different sources and ages.Marine organic matter has been shown to have high complexing capacity. Productive superficial and intermediate waters as well as deep waters showed relatively high and comparable complexing capacity indicating that old organic matter may have strong complexing sites.  相似文献   

10.
通过对诏安湾海域6个站位的水文泥沙观测和181个表层沉积物样品的粒度分析,结合海湾水深地形,应用Gao?Collins粒径输运模型和系统聚类分析方法,分析研究了福建诏安湾海域的粒度参数分布特征、表层沉积物的运移趋势和沉积环境划分及其动力机制.结果表明,诏安湾表层沉积物共6种类型,以黏土质粉砂和砂为主,平均粒径介于0.5...  相似文献   

11.
On the basis on the experimental hydrological data accumulated in the database of the Marine Hydrophysical Institute of the Ukrainian National Academy of Sciences and the meteorological data of the Marine Department of the Ukrainian Scientific-Research Hydrometeorological Institute, we study the characteristics of seasonal variability of the processes of renewal, freshening, and salinization of waters in the Karkinit Bay. We analyze and estimate the repeatability of the inflows of salt and freshened waters from the sea as well as the variations of the areas occupied by these waters in the water area of the bay depending on the seasonal and wind conditions. For the spring-summer period, we estimate the period of renewal of waters in the upper layer of the main part of the bay (11–14 days). A time interval of possible absence of noticeable water exchange between the main and east shallow parts of the bay (of about two months) is revealed in the summer-autumn period. __________ Translated from Morskoi Gidrofizicheskii Zhurnal, No. 4, pp. 24–39, July–August, 2007.  相似文献   

12.
Experimental data provided by a hydrophysical profiling probe are invoked to examine the vertical and horizontal structures of the north equatorial countercurrent in the Atlantic Ocean. The kinematics of waters and the hydrological element distribution are compared. The countercurrent's major parameters have been identified and volume transport has been calculated.Translated by V.Puchkin.  相似文献   

13.
The structure of the bottom sediments in Kara Bogaz Gol Bay is correlated with the history of the sea level fluctuations in the Caspian Sea during the Novocaspian time based on the radiocarbon geochronology of the coastal and bottom sediments. Instrumental observations of the sea level and the hydrochemical regime of the bay are considered to substantiate the correlations obtained.  相似文献   

14.
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.  相似文献   

15.

Cruise 81 of the R/V Akademik Mstislav Keldysh was organized by Shirshov Institute of Oceanology and took place from August 27 to September 25, 2020 under the Program “Marine Ecosystems of the Siberian Arctic.” Participants included 76 scientists from the institutes of Russian Academy of Sciences, Moscow State University, VNIRO, and the NRC Kurchatov Institute and specialists from the Emergency Situations Ministry. Coordinated hydrophysical, hydrochemical, biooceanological, geochemical, and radioecological research was carried out over the Kara Sea, on the shelf near the St. Anna Trough, the continental slope, the Novaya Zemlya depression, and bays of the eastern coast of Novaya Zemlya. The condition of disposed radioactive waste in bays of the archipelago was assessed.

  相似文献   

16.
The concentration distribution was studied for dissolved oxygen, phosphorus forms, and particulate matter in Curonian Bay of the Baltic Sea in poorly known consolidated ice cover conditions during the winter seasons of 2010, 2011, and 2013. The surface and near-bottom waters were sampled at 51 stations. The ice cover exerts no significant effect on the typical seasonal variation of all considered parameters in the basin. The concentrations of mineral and organic phosphorus in the bay appeared to be lower by factors of 2–4 compared to summer values. A two- to threefold decrease in the concentrations of organic phosphorus since 2010 to 2011 and then to 2013 was recorded in the bay, which resulted from a decrease in phosphorus production by phytoplankton. Despite water being isolated from air by ice, the absence of wave mixing, and the decrease in oxygen production owing to the seasonal winter decrease in the intensity photosynthetic processes, no oxygen deficiency was found in the basin. This is because oxygen supplied to the bay by river runoff and production by photosynthesis in the bay exceed the utilization for oxidation of organic matter resulting from low bioproductivity of the waters during winter. The winter decrease in the fraction of biogenic particulate matter is seen as a four- to sevenfold drop in its total concentration in the waters compared to summer seasons. The absence of wave roiling of bottom sediments also caused a decrease in the secondary supply of biogenic particulate matter from sediments into near-bottom waters. No negative trends of geoecological conditions in the bay were revealed by the studied parameters under consolidated ice cover conditions.  相似文献   

17.
The geochemistry of dissolved copper-organic complexes was investigated in the estuarine waters of Narragansett Bay. A transect survey was conducted in August 1980, while one mid-bay station was monitored from March through August of that year. The transect data indicated that most of the copper-organic complexes enter the bay via sewage effluent which is discharged into the Providence River at the head of the bay. Organic copper concentrations in the estuary ranged from 0.12 to 2.30 μg kg?1 and comprised from 14 to 70% of the total dissolved copper. The concentration of copper-organic complexes was not directly related to the amount of dissolved organic matter; and recently generated organic material from phytoplankton production within the bay had a negligible influence on the fraction of dissolved copper which was organically bound.The major source of total copper to the bay is anthropogenic inputs from sewage effluents. Particulate and dissolved copper concentrations ranged from 0.06 to 2.42 and 0.23 to 16.4 μg kg?1, respectively, giving average values of about 40% particulate and 60% dissolved copper. Particulate copper concentrations decreased rapidly from the upper to the lower bay as a result of both removal and dilution. About 75% of the dissolved copper entering the bay is rapidly removed in the Providence River and upper bay, and the remaining portion (which is largely organic copper) follows conservative mixing in the mid to lower bay. The data suggest that copper binding by dissolved organic matter may be an important control on the riverine flux of dissolved copper through estuaries into coastal and oceanic waters.  相似文献   

18.
The hydrochemical features of Ob Inlet in the open-water time were characterized using the data of the surveys during two seasons of different water content. The inlet was subdivided into the “riverine,” “marine,” and intermediate areas being different in the factors determining their hydrochemical regime. The processes occurring in each of the distinguished areas were considered in detail. Special attention was paid to the hydrochemical features in the mixing area of the fresh and saline waters (the frontal zone) within the periods of the maximum and minimum biological activity in the aquatic area of Ob Inlet.  相似文献   

19.
Seasonal, sub-seasonal and spatial fluctuations in bottom dissolved oxygen (DO) were examined in St Helena Bay, South Africa’s largest and most productive embayment, between November 2013 and November 2014. Alongshore bay characteristics were assessed through comparison of variables along the 50-m depth contour. A mean coefficient of variation of 0.35 provided a measure of the relative variability of near-bottom DO concentrations along this contour. Consistently lower DO concentrations in the southern region of the bay in summer and autumn are attributed to enhanced retention. Across-shelf transects captured the seasonal development of hypoxia in relation to the distribution of phytoplankton biomass. Exceptional dinoflagellate blooms form extensive subsurface thin layers preceding the autumn DO minima in the south of the bay, prior to winter ventilation of the bottom waters. The seasonal decline in DO concentrations in the bottom waters was marked by sub-seasonal events of hypoxia, and ultimately anoxia linked to episodic deposition of organic matter, as indicated by increases in bottom chlorophyll-a concentrations. Seasonal changes in bottom water macronutrient concentrations followed trends in apparent oxygen utilisation (AOU), both of which mirrored DO concentrations. In the south of the bay, nitrogen loss through denitrification/anammox in suboxic waters was indicated by a dissolved inorganic N deficit in the bottom waters, which was most pronounced in autumn.  相似文献   

20.
We present the results of biological and oceanographic investigations performed in the Weddell and Scotia Seas within the framework of the first (January–June, 1997) and second (January–June, 1998) Ukrainian Antarctic marine expeditions. We reveal some regularities in the space distribution of the aggregations of krill and salpae depending on the abiotic (hydrophysical) environmental factors and discuss possible mechanisms promoting the formation of aggregations of krill and salpae in the Antarctic waters.  相似文献   

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