共查询到20条相似文献，搜索用时 15 毫秒
1.
The conditions of transformations of biogenic substances and the redistribution of their concentrations in the shelf water
of Sakhalin Island are studied. Preliminary works have given the results for the water area of La Perouse Strait and Aniva
Bay (the Sea of Okhotsk), while this paper gives such results for Tatar Strait (the Sea of Japan). Three electronic instruments
of oceanographic studies are applied: an adapted version of Bergen Oceanic Model (for the reconstruction of the space and
time distribution of seawater temperature, salinity, and density; the circulation intensity of water masses; and water exchange
parameters with nearby water areas and within the strait); GIS “Sakhalin Shelf” (for the reconstruction of annual variations
in thermohaline characteristics on a standard grid and horizons of oceanographic stations, and the parameters of the aquatic
environment); hydroecological CNPSi-model (for studying the annual dynamics of biogenic element compounds, the biomasses,
biohydrochemical activity and bioproduction of microorganisms—bacteria, phytoplankton, and zooplankton, taking part in transformation
of biogenic substances and petroleum hydrocarbons, as well as the internal fluxes of biogenic substances governed by the activity
of microorganisms and the external load on the marine ecosystem). The results of modeling the spatial transport of biogenic
substances through the outer boundaries of Tatar Strait water area and the boundaries of the three areas identified within
it are presented and discussed. 相似文献
2.
The state of the marine environment (the temperature, light intensity, transparency, biogenic load) in Tatar Strait was assessed
based on mean annual data from literary sources and with the use of GIS “Sakhalin Shelf.” The entire strait was divided into
three regions (northern, southwestern, and southeastern), and water exchange between them for each month was estimated by
using Bergen Oceanic Model. The information about the state of the marine environment and water exchange characteristics was
used as input data for a hydroecological model, which enabled the assessment of annual variations of biogenic substance concentrations
and biomasses of microorganisms (heterotrophic bacteria, three groups of phytoplankton, and two groups of zooplankton) in
the strait regions chosen. The development conditions of microorganism biomasses within the year can be characterized by their
activity indices (specific growth rates), the values of internal fluxes of biogenic substances, and calculated bioproductivity
values. The calculated biogenic substance concentrations and phytoplankton bioproductivity values showed good agreement with
the estimates for the Sea of Japan and Tatar Strait available from the literature. 相似文献
3.
Numerical modeling with the help of an oceanic model developed in the Bergen University and with mean annual data was used to carry out monthly calculations of water circulation fields in Tatar Strait, to calculate the vertical velocities and horizontal transfer rates between three areas identified within the strait and on its external boundaries. Analysis of calculation results revealed new features in water circulation in the strait (in particular, in winter) and made it possible, for the first time, to jointly evaluate water exchange components on the external boundaries and within the strait. 相似文献
4.
Statistical modeling and GIS “Sakhalin Shelf” are used to restore the annual variations of water temperature and salinity
at standard oceanographic stations in Tatar Strait, where observation series are about 45 years long. Numerical modeling techniques
with the help of Bergen University model are used to restore the spatial fields of water temperature and salinity. Analysis
of calculation results made it possible to identify new features of the hydrological regime in the strait, in particular,
during winter, for which no generalizations have been made before. 相似文献
5.
A hydroecological model is used for simultaneous studying water pollution processes by petroleum hydrocarbons and their decay
under the oceanographic conditions of Tatar Strait. The model calculations were based on long-term averaged observational
data on interannual variations of water temperature, light intensity, and transparency. Some oceanographic characteristics
of the strait were reconstructed with the help of GIS “Sakhalin Shelf.” The strait’s water area was divided into three regions,
and water exchange between them and the neighboring regions of the Sea of Japan was estimated by a hydrodynamic model. The
results of the study made it possible to assess interannual variations in the concentrations and inner fluxes of petroleum
hydrocarbons, oil-oxidizing bacteria biomasses, and the characteristics of their oxidation activity. 相似文献
6.
Methods of statistical analysis and GIS Sakhalin Shelf have been used to reconstruct the annual variations of water temperature, salinity, and density from the surface to the bed at 60 standard oceanographic stations on northeastern Sakhalin shelf (with the total duration of observations of ～40 years). Numerical simulation using Bergen University oceanic model has been applied to calculate the spatial fields of water temperature and salinity at standard horizons in nodes of a regular grid. The analysis of calculation results revealed new features of the hydrological regime and gave previously unknown thermohaline fields with maximal detail for full annual cycle. The obtained data were used to evaluate the mean monthly three-dimensional water circulation. 相似文献
7.
Ocean circulation influences nearly all aspects of the marine ecosystem. This study describes the water circulation patterns on time scales from hours to years across Torres Strait and adjacent gulfs and seas, including the north of the Great Barrier Reef. The tridimensional circulation model incorporated realistic atmospheric and oceanographic forcing, including winds, waves, tides, and large-scale regional circulation taken from global model outputs. Simulations covered a hindcast period of 8 years (i.e. 01/03/1997–31/12/2004), allowing the tidal, seasonal, and interannual flow characteristics to be investigated. Results indicated that the most energetic current patterns in Torres Strait were strongly dominated by the barotropic tide and its spring-neap cycle. However, longer-term flow through the strait was mainly controlled by prevailing winds. A dominant westward drift developed in summer over the southeasterly trade winds season, which then weakened and reversed in winter over the northwesterly monsoon winds season. The seasonal flow through Torres Strait was strongly connected to the circulation in the north of the Great Barrier Reef, but showed little connectivity with the coastal circulation in the Gulf of Papua. Interannual variability in Torres Strait was highest during the monsoon period, reflecting variability in wind forcing including the timing of the monsoon. The characteristics of the circulation were also discussed in relation to fine sediment transport. Turbidity level in Torres Strait is expected to peak at the end of the monsoon, while it is likely to be at a low at the end of the trade season, eventually leading to a critically low bottom light level which constitutes a severe risk of seagrass dieback. 相似文献
8.
An atlas of oceanographic data on the shelf zone of Sakhalin Island and a mathematical model describing the transformations of nutrient compounds (N, P, Si, C) are used to study the biotransformation and transport of organic and mineral components of these elements in the La Perouse Strait. To make the analysis more convenient, the area under examination was divided into four zones, which differ in the conditions of transport of matter in water flows. Transport calculations are made using a complex graphic method with geostrophic approximation, which takes into account the results of instrumental observations of flow velocities, sea level variations, and annual variations in the water volumes. The obtained patterns of dynamics of nutrient compounds are compared with the results of modeling of internal and external fluxes of those components. Calculated fluxes of the elements were used to assess the rate of chemicals and biomass transport through the boundaries of water areas (in particular, between the Seas of Japan and Okhotsk). 相似文献
9.
Functioning of the White Sea Ecosystem: Studying the Transformations of Organogenic Substances Using a Mathematical Model 总被引：1，自引：0，他引：1
Long-term observational data on hydrology, hydrochemistry, and hydrobiology are generalized and used for systems analysis of the biohydrochemical transformation processes of organic and biogenic substances in a marine environment. An ecological model with the systematized data is used to assess the annual dynamics of concentrations of organic and mineral N, P, and Si compounds and dissolved organic C and O2 in eight water areas within the White Sea at specified conditions of water mass transport, river runoff, and water exchange with the Barents Sea. Variations in the biomasses of the major transformers of organic and biogenic substances (heterotrophic bacteria, phyto- and zooplankton, and microphytes) and their biological production were also evaluated. These characteristics serve as indicators of the state of the water environment, the presence of nutrients in it, and their import from outside. 相似文献
10.
T. A. Mikhailik P. Ya. Tishchenko A. M. Koltunov P. P. Tishchenko M. G. Shvetsova 《Water Resources》2011,38(4):512-521
Seasonal variations in biogenic substances (nitrates, nitrites, ammonium, phosphates, and silicates), dissolved oxygen, dissolved
organic matter, chlorophyll, humus, and suspended matter at seven stations on the Razdol’naya River are examined. Based on
seasonal variations, the local sources of river water pollution by biogenic substances were identified. The annual and daily
fluxes of biogenic substances through the Razdol’naya River into Amur Bay are calculated. A diffuse pollution source—agricultural
fields in river valley—are shown to be the main source of biogenic substance fluxes. The vast hypoxia in the bottom water
of Amur Bay, detected by the authors in 2007 and 2008, is supposed to be mostly caused by floods on the Razdol’naya R., which
create favorable conditions of water blooming in Amur Bay in summer. The biomass of dead phytoplankton, experiencing microbiological
decomposition and oxidation, causes hypoxia of bottom waters in the bay. 相似文献
11.
On the dynamics of strait flows: an ocean model study of the Aleutian passages and the Bering Strait
A high-resolution numerical ocean circulation model of the Bering Sea (BS) is used to study the natural variability of the BS straits. Three distinct categories of strait dynamics have been identified: (1) Shallow passages such as the Bering Strait and the Unimak Passage have northward, near barotropic flow with periodic pulses of larger transports; (2) wide passages such as Near Straits, Amukta Pass, and Buldir Pass have complex flow patterns driven by the passage of mesoscale eddies across the strait; and (3) deep passages such as Amchitka Pass and Kamchatka Strait have persistent deep return flows opposite in direction to major surface currents; the deep flows persist independent of the local wind. Empirical orthogonal function analyses reveal the spatial structure and the temporal variability of strait flows and demonstrate how mesoscale variations in the Aleutian passages influence the Bering Strait flow toward the Arctic Ocean. The study suggests a general relation between the barotropic and baroclinic Rossby radii of deformations in each strait, and the level of flow variability through the strait, independent of geographical location. The mesoscale variability in the BS seems to originate from two different sources: a remote origin from variability in the Alaskan Stream that enters the BS through the Aleutian passages and a local origin from the interaction of currents with the Bowers Ridge in the Aleutian Basin. Comparisons between the flow in the Aleutian passages and flow in other straits, such as the Yucatan Channel and the Faroe Bank Channel, suggest some universal topographically induced dynamics in strait flows. 相似文献
12.
Mathematical modeling is used to study the conditions of natural biotransformation of biogenic element compounds (containing C, N, P, Si) in five areas within Aniva Bay. The input data for the model are evaluated with the use of GIS “Sakhalin Shelf” and the available reference literature on the bay oceanography. Water masses that transferred through the boundaries between the areas were evaluated based on the values of water level, river runoff, atmospheric precipitation, evaporation, and the volume of water in the bay, all of which vary as a result of water heating. The model was used to evaluate annual variations in the concentrations of organic and mineral fractions of these elements and the biomasses of planktonic organisms for the five areas in the bay. Modeling results also allowed the assessment of biogenic substance input with river runoff into Lososei Bay. Based on the internal fluxes of substances, the monthly and annual aquatic animal production was evaluated. 相似文献
13.
The problems of flow dynamics in a near-island zone of a shallow channel is considered using as an example the Bjerkezund Strait (eastern Gulf of Finland). Preliminary results of field studies and the results of numerical modeling of water circulation in the strait are given. 相似文献
14.
Tidal and residual currents in the Bransfield Strait,Antarctica 总被引：1，自引：0，他引：1
During the 1992–1993 oceanographic cruise of the Spanish R/V Hespérides, recording equipment was deployed in the Bransfield Strait. Six Aanderaa RCM7 current meters and three Aanderaa WLR7 tide gauges were successfully recovered after an operation period of 2.5 months. Relevant features of the time series obtained are presented and discussed in this paper. The emphasis is placed on the tidal character of the currents and the relative importance of tidal flow in the general hydrodynamics of the strait. For these purposes a dense grid of hydrographic stations, completed during the BIOANTAR 93 cruise, is used. Preliminary geostrophic calculations relative to a 400 m depth, yield current velocities of around 0.20 m s−1 in the study area, whereas the magnitude of tidal currents is seen to be 0.30-0.40 m s−1. 相似文献
15.
Sergey V. Prants Andrey G. Andreev Michael Yu. Uleysky Maxim V. Budyansky 《Ocean Dynamics》2014,64(6):771-780
Using Lagrangian methods, we analyze a 20-year-long estimate of water flux through the Kamchatka Strait in the northern North Pacific based on AVISO velocity field. It sheds new light on the flux pattern and its variability on annual and monthly time scales. Strong seasonality in surface outflow through the strait could be explained by temporal changes in the wind stress over the northern and western Bering Sea slopes. Interannual changes in a surface outflow through the Kamchatka Strait correlate significantly with the Near Strait inflow and Bering Strait outflow. Enhanced westward surface flow of the Alaskan Stream across the 174°E section in the northern North Pacific is accompanied by an increased inflow into the Bering Sea through the Near Strait. In summer, the surface flow pattern in the Kamchatka Strait is determined by the passage of anticyclonic and cyclonic mesoscale eddies. The wind stress over the Bering basin in winter–spring is responsible for eddy generation in the region. 相似文献
16.
The data collected for model calculations is systematized for natural and design conditions. The natural conditions did not take into account the effect of the complex of water-protection structures on the hydrological regime of Neva Bay and on the biogenic load onto this water area, while the design conditions, conversely, reflected the possible impact of those structures on the hydrology and ecology of the area. Numerical experiments were used to study the processes of transformation of N and P compounds and the dynamics of dissolved O2 in Neva Bay water area. In the comparison of the calculated and observed concentrations of biogenic substances, Theil criterion was evaluated to assess the adequacy of the model in reproducing the concentration fields of the distribution of biogenic substances over Neva Bay water area. The major qualitative and quantitative features of the formation of the spatial heterogeneity and the time variations in the concentrations of biogenic element compounds over Neva Bay water area are identified. Possible improvements of the model in the reproduction of the complex of processes that are of particular importance for the development of substance transformations in shallow ecosystems are considered. 相似文献
17.
Normal annual data are used to evaluate the within-year variations in the concentrations of biogenic substances (organic and mineral components of N and P, dissolved organic carbon, inorganic Si) in the major tributaries of the Caspian Sea. Variations in the concentrations of biogenic substances are analyzed, the relationships between their mass concentrations in individual months are evaluated, and correlation between the organic and mineral components of N and P and their aggregated fractions are established. The obtained high-significance correlation between the concentrations of N and P components suggests that the rates of biochemical processes of biogenic substance transformation taking place in the water of tributaries are commensurable. 相似文献
18.
Gómez F 《Marine pollution bulletin》2003,46(6):685-694
The role of the Strait of Gibraltar on the exchanges of substances between Mediterranean Sea and the Atlantic Ocean is reviewed. The previous estimations have been recalculated by using a similar water flux and compared with the river and atmospheric inputs to the Western Mediterranean Sea. The man-induced changes in the dimensions of the Strait of Gibraltar increasing (planning the sill) or reducing of the cross-section by a total or partial dam are discussed. A total dam will control the sea-level rise in the Mediterranean Sea, but an annual increase of major nutrient concentrations of 1-2% could be expected, lower than the rate of increase of the river and atmospheric inputs in the Western Mediterranean Sea. The increase of the cross-section of the Strait by increasing the depth (planning) at the sill could compensate the increase of the external nutrient inputs. 相似文献
19.
The transformation conditions of oil hydrocarbons in water are considered for the case of Karkinitskii Bay, the Black Sea, where gas deposits have been developed actively in recent years and oil product pollution of marine environment has been recorded repeatedly. Data on measured oil hydrocarbon concentrations, their input into the northwestern part of the Black Sea, and experimental estimates of oil decomposition in the marine environment are presented. The biotransformation conditions of oil hydrocarbons are simulated by reproducing the biochemical activity of microflora and effecting substrate consumption processes, metabolic product excretions, and biomass decay. These processes maintain the biogenic substance turnover in water environment. The calculations are based on the morphometric characteristics of Karkinitskii Bay, and mean long-term data on the monthly dynamics of marine environmental characteristics (temperature, light intensity, transparency, atmospheric precipitation, and the characteristics of water regime and Danube runoff). A check calculation was performed to reproduce the concentration dynamics of biogenic substances and oil products with allowance made for the effect of river runoff and background pollution of the marine environment. The numerical scenarios take into account the marine environmental pollution conditions (an immediate discharge of 1000, 500, or 200 t of oil products per week) in winter, spring, summer, and autumn. The obtained model estimates of the rates of oil product decomposition and oxygen consumption are shown to agree well with experimental data. The time required for the concentration of oil products to reach the MAC after pollution of the marine environment is estimated. 相似文献
20.
Study on the transverse structures across Taiwan Strait 总被引：3，自引：0，他引：3
The mountain ranges are almost NE- or NNE-trending in mainland and Taiwan island across the strait. But a number of correspondent
transverse structures across Taiwan Strait have been identified on the basis of morphology, surface structure, deep seismic
survey and gravity field etc. Moreover, it is inferred from the square or/and rectangular shape of the isoseist maps of 8
M≥ 6 earthquakes occurring in the western foothill plain of Taiwan that there is an apparent segmentation of the Taiwan Island
along the N-S orientation. This has been verified from the GPS’s results of the ground motions measured during the Chi-Chi
earthquake in 1999. As a matter of fact, the transverse structures within the Taiwan Island could be correlated with more
salient NW- and EW-trending structures in the mainland of Fujian than in Taiwan. The investigation of the transverse structures
across Taiwan Strait is conducive to realizing the geology within the strait. Hence, the tectonic sketch map of the strait
as well as mainland and island drawn in this context shows NW- and EW-trending structures for the study area. 相似文献