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1.
V. L. Dorofeev G. K. Korotaev L. I. Sukhikh 《Izvestiya Atmospheric and Oceanic Physics》2013,49(6):622-631
Using an interdisciplinary three-dimensional physical and biogeochemical model developed for the Black Sea, the long-term evolution of marine dynamics and ecosystem is investigated. The hydrophysical fields were calculated from a model of Black Sea circulation with assimilation of hydrographic survey and satellite measurement data from 1971 to 2001. The circulation model reproduces well processes of various scales in both space and time (particularly the seasonal course and interannual variability of main hydrophysical fields). The resulting flow fields are then used to calculate the long-term evolution of the components of the lower level of the food chain in the Black Sea ecosystem. The biogeochemical model used in the calculations is based on the nitrogen cycle and includes a parameterization of the main biological and chemical interactions and processes in the upper layer of the Black Sea. The numerical experiments indicated that the biogeochemical component of the model rather successfully reproduces the main features and evolution trends in the Black Sea ecosystem for the period under consideration: the growth in the phytoplankton biomass during eutrophication and changes in seasonal cycles of the main ecosystem components. Also, the hydrophysical processes were shown to be important for a reliable reproduction of long-term changes in the ecosystem. 相似文献
2.
The formation of the fields of surface winds over the Black Sea occurs under the action of numerous physical factors. One
of the most important factors is the monsoon mechanism connected with the seasonal variations of buoyancy contrasts over the
sea and surrounding land. To separate the effects caused by this mechanism, we performed and described the numerical experiments
aimed at the evaluation of the sensitivity of the regional model of atmospheric circulation to the variations of land–sea
temperature contrasts. It is shown that the influence of these effects is restricted to the lower part of the atmosphere.
The presented estimates of the climatic fields of disturbances enable us to describe the monsoon mechanism specifying the
seasonal variability of the field of vorticity of the wind velocities and, as a consequence, the seasonal variability of the
large-scale circulation of waters in the Black Sea. 相似文献
3.
On the basis of a simple stationary linear model and a contemporary nonlinear model, we study the mesoscale characteristics
of the fields of vertical velocity and vorticity of winds over the Black Sea. It is shown that, in the idealized case (without
taking into account the coastal features), the temperature contrast between the land and the sea in both models leads to the
formation of circulation cells in the coastal zone. However, the mountainous features prove to be the main factor affecting
the process of circulation for the actual synoptic situations. We present the map of monthly average vorticity of the surface
winds constructed according to the nonlinear mesoscale model with a resolution of 30 km for January 1996–2001.
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Translated from Morskoi Gidrofizicheskii Zhurnal, No. 1, pp. 52–61, January–February, 2005. 相似文献
4.
We develop a semiempirical spectral model of penetrating irradiance taking into account the biooptical characteristics of
the Black Sea. The evaluation of the contributions of the principal optically active components to the total absorption of
light in the sea shows that, in the short-wave range (400–500 nm), light is mainly absorbed by the dissolved organic matter
(41–77%). The contribution of phytoplankton to the total absorption attains its maximum values (26–37%) in the abyssal part
of the sea in the period of spring blooming of diatoms. In the coastal waters, the absorption of light by suspended nonalgae
particles in summer is almost twice as intense (20–30%) as in the open sea (8–13%). The analysis of the sensitivity of our
model shows that the absorption of light by dissolved organic matter is more significant for the estimation of the photosynthetically
active radiation in the Black Sea than the concentration of pigments and backscattering of light by suspended particles. The
comparison of the results of model computations with the data of measurements of the underwater irradiance reveals high accuracy
of the proposed model. 相似文献
5.
N. A. Diansky V. V. Fomin N. V. Zhokhova A. N. Korshenko 《Izvestiya Atmospheric and Oceanic Physics》2013,49(6):611-621
We suggested a method for modelling the transport of pollutants over the Black Sea water basin adjacent to Big Sochi. The model is based on the application of the Institute of Numerical Mathematics Ocean Model (INMOM) over the entire basin of Big Sochi in two versions: M1 and M2. In the first version, we use uniform spatial resolution of the model with a step of ～4 km; in the M2 version, the resolution is not uniform. The step decreases to 50 m in the basin of Big Sochi. The M2 version is used only in the periods when pollution transport is simulated, for which the initial hydrothermodynamic state is specified from the M1 version. Both versions reflect a complex character of Black Sea circulation; however, the M2 version more adequately reproduces the eddy circulation in its eastern part, where the horizontal resolution of the M2 version is higher. A conclusion is made on this basis that, in order to reproduce the eddy structure of the Black Sea circulation, the resolution of the model should be on the order of 1.5 km and the main factor of the formation of the quasi-stationary Batumi anticyclonic eddy is the topographic peculiarities in this part of the sea. The pollution spreading from the Sochi, Khosta, and Mzymta rivers and from 18 pipes of deep-water sewage was simulated for the flood periods from April 1, 2007, to April 30, 2007. It was shown that mesoscale eddy formations that form a complex three-dimensional structure of pollution spreading make the greatest contribution to the spread of pollution. 相似文献
6.
For the Black-Sea region, we perform the dynamic reanalysis of the data on atmospheric circulation for the period 1958–2001
by using the HadRM3P model with a space resolution of 25 km. We estimate the mean climatic atmospheric fields of vorticity and divergence of the
wind velocity and study their space structure and seasonal variability. The climatic estimates of the annual course of vorticity
of the wind velocity over the sea are presented. The obtained large annual average values of vorticity of the velocity reveal
the predominant role played by the wind action in the generation not only of the seasonal variability but also of the mean
cyclonic circulation of waters in the Black Sea. 相似文献
7.
Estimation of horizontal salt transfer from the central part of the Black Sea to the continental slope is carried out based on numerical modeling. A box hydrodynamic model of the Black Sea based on the POM model is used. Horizontal transport caused by seasonal variability of vertical velocity in the central part of the Black Sea and horizontal turbulent diffusion is considered. In this work we demonstrate that, in the 0- to 30-m layer on average for the year, there is an outflow of salty water under the impact of both factors. In the surface layer, the transport caused by seasonal variability contributes significantly (30%). In the 80- to 150-m layer on average over the year, the waters from the continental slope arrive into the central part of the basin; they are characterized by higher salinity due to the inflow of the Marmara Sea waters across the Bosporus Strait. 相似文献
8.
涡旋对海洋中的能量传递和物质交换有重要作用。黑海西北部陆坡边缘是长生命周期涡旋经常发生的海域,但涡旋引起的陆架和海盆之间水交换通量的季节性特征,以及海盆边缘环流对跨陆架水交换的作用等方面的研究还不是很充分。本文对黑海西北部陆架区与深海盆区间的跨陆架水交换进行了研究,利用高分辨率三维原始方程模式模拟的温、盐、流等资料,结合涡旋自动探测方法,统计了黑海西北部海域的涡旋活动,研究了涡致跨陆架水交换的季节性特征,计算对比了2002年到2010年间海盆边缘环流与涡旋对跨陆架水交换通量的各自贡献。结果表明:黑海西北部地区海盆边缘环流强度与跨陆架进、出通量的相关系数分别为0.57和0.67,海盆边缘环流位置与跨陆架交换量的相关系数为0.52;海盆边缘环流强度与位置的季节性变化导致了黑海西北部跨陆架通量的季节性变化。黑海西北部地区表层3月到8月之间涡旋所引起跨陆架交换量约占了跨陆架交换总量的16%~31%;涡致跨陆架通量也具有季节性特征。文中对单个涡旋进行了详细研究:2005年5月5日到2005年7月20日之间在黑海西北部存在一个直径最大值时达到120 km的反气旋式涡旋,涡旋存在期间完成了从陆架区向深海区的水体传输,相当于黑海西北陆架区水体积的30.9%。 相似文献
9.
《Deep Sea Research Part I: Oceanographic Research Papers》1999,46(4):597-636
A one-dimensional, vertically resolved, physical–biochemical upper ocean model is utilized to study plankton productivity and nitrogen cycling in the central Black Sea region characterized by cyclonic gyral circulation. The model is an extension of the one given by Oguz et al. (1996, J. Geophys. Res. 101, 16585–16599) with identical physical characteristics but incorporating a multi-component plankton structure in its biological module. Phytoplankton are represented by two groups, typifying diatoms and flagellates. Zooplankton are also separated into two groups: microzooplankton (nominally <200 μm) and mesozooplankton (0.2–2 mm). The other components of the biochemical model are detritus and nitrogen in the forms of nitrate and ammonium. The model incorporates, in addition to plankton productivity and organic matter generation, nitrogen remineralization (ammonification) and ammonium oxidation (nitrification) in the water column. Numerical simulations are described and compared with the available data from the central Black Sea. The main seasonal and vertical characteristics of phytoplankton and nutrient dynamics inferred from observations appear to be reasonably well represented by the model. Fractionation of the biotic community structure is shown to lead to increased plankton productivity during the summer period following the diatom-based early spring (March) bloom. The annual nitrogen budget for the euphotic zone reveals the substantial role of recycled nitrogen in the surface waters of the Black Sea. 相似文献
10.
The paper analyses results of the numerical simulation of upwelling events in the north-western part of the Black Sea, mostly
near the South Crimea. The calculations were performed using a numerical model based on primitive hydrodynamics equations.
Emphasis is laid on the case when a salinity front simulating the Black Sea rim current is prescribed in the initial conditions.
The interaction of the Black Sea rim current's stream with the coastline and bottom topography leads to the development of
an upwelling near the Crimea's coast, even in the absence of wind forcing. The paper discusses the structure of the three-dimensional
circulation of waters in the shelf area of the NW Black Sea. Numerical modelling results are matched up with the satellite
data obtained by the HRPT receiving station.
Translated by Vladimir A. Puchkin. 相似文献
11.
12.
Model of palaeoenvironmental evolution of the Black Sea region during the last glacial maximum—Holocene 总被引：1，自引：0，他引：1
I. Genov 《Oceanology》2009,49(4):540-557
A model for the palaeoenvironmental evolution of the Black Sea and its adjacent basins during the past 20.000 years, in which
variations in sedimentation, erosion, and hydrologic processes as a result of climatic change are taken into consideration,
is developed. The data used include those from five cruises in the Black Sea with the participation of the author, seismo-acoustic
data in the possession of the Institute of Oceanology in Varna, and data from the published literature. The most important
result is that the water level of the Black Sea is controlled largely by that of the Marmara Sea via the Bosporus sill. The
water circulation in the south part of the Bosporus channel as natural regulative mechanism of the Black Sea level during
11800–9000 yr C14 BP is produced. A succession of climatic and water conditions for the Black Sea by pollen analysis is presented. The linear
ridges on the Black Sea shelf as result of the lower Holocene regression are proved by means of a stratigraphic interpretation
of the seismo-acoustic profiles. The levels of the Black Sea, Marmara Sea, and Mediterranean at regarded intervals of time
are presented. An attempt at explanation of maximum number of facts from the study region with this model is made. 相似文献
13.
On the basis of the generalized data of multiannual observations (1985–1994), we analyze the seasonal variability of the vertical
and spatial distributions and composition (Csos, Nsos, Csos/cha, and C/N) of suspended organic substances (SOS) in the shelf zone and in the upper active layer of the abyssal part of the
Black Sea. The results of our analysis enable us to conclude that only a narrow coastal band of the shelf in the northwest
and west parts of the sea suffers to an extremely pronounced anthropogenic impact, which manifests itself in a significant
increase in the mass of suspended organic substances. The formation of new organic substances and, hence, the mass of suspended
organic substances in these regions attain the level of eutrophic waters in the late-spring and summer periods. In the open-sea
region, the anthropogenic impact is less pronounced and the spatial distribution of suspended organic substances is determined
by the general dynamics of waters and the intensity of phytoplankton production.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
14.
A five-year study of the interannual changes observed in May–June during the mass reproduction of coccolithophorids was carried
out in the northeastern part of the Black Sea. The long-term dynamics were analyzed using the data on the phytoplankton collected
during the last 40 years. The fraction of coccolithophorids represents either 20 or 60% of the total biomass of the algae
and does not depend on either the previous winter conditions or the nitrogen content and the N: P ratio in the surface water
layer. Our studies have revealed the dependency between the phosphate content and the size of the coccolythophorids’ fraction
in the total phytoplankton biomass. The long-term population dynamics includes three periods. Until the mideighties, the coccolythophorid
fraction in the Black Sea phytoplankton was insignificant (3%). The average biomass was equal to 8 μg/l. In the late eighties,
the average biomass increased up to 106 μg/l. Since the midnineties, coccolythophorids often prevail in the number and mass
among the other phytoplankton species. The general tendency for the growth of the coccolythophorid fraction in the phytoplankton
cenoses coincides with the increase in the phosphate concentration in the near-surface water observed within the last 40 years.
This fact corresponds to the experimental results, which demonstrate that the coccolythophorid development during May–June
is phosphate-limited. 相似文献
15.
V. M. Sergeeva I. N. Sukhanova M. V. Flint L. A. Pautova J. M. Grebmeier L. W. Cooper 《Oceanology》2010,50(2):184-197
The phytoplankton community was studied in Bering Strait and over the shelf, continental slope, and deep-water zones of the
Chukchi and Beaufort seas in the middle of the vegetative season (July–August 2003). Its structure was analyzed in relation
to ice conditions and the seasonal patterns of water warming, stratification, and nutrient concentrations. The overall ranges
of variation in phytoplankton abundance and biomass were estimated at 2.0 × 102 to 6.0 × 106 cells/l and 0.1 to 444.1 mg C/m3. The bulk of phytoplankton cells concentrated in the seasonal picnocline, at depths of 10–25 m. The highest values of cell
density and biomass were recorded in regions influenced by the inflow of Bering Sea waters or characterized by intense hydrodynamics,
such as the Bering Strait, Barrow Canyon, and the outer shelf and slope of the Chukchi Sea. In the middle of the vegetative
season, the phytoplankton in the study region of the Western Arctic proved to comprise three successional (seasonal) assemblages,
namely, the early spring, late spring, and summer assemblages. Their spatial distribution was dependent mainly on local features
of hydrological and nutrient regimes rather than on general latitudinal trends of seasonal succession characteristic of arctic
ecosystems. 相似文献
16.
G. S. Karabashev 《Oceanology》2011,51(1):36-38
Based on the comparative analysis of the characteristics of the early summer maxima of the normalized radiance from the satellite
ocean color data, the seasonal trend of the concentration of the chlorophyll “a,” and the species composition of the phytoplankton
from determinations in water samples from the Black Sea, it is concluded that the summer chlorophyll maximum is due to the
coccolithophorid bloom occurring from late May to mid June in the Black Sea basin. 相似文献
17.
We analyse the time variability of the fields of Cs-137 concentration in the surface waters of the Black and Mediterranean
Seas in 1986–1998. It is shown that more contaminated Black-Sea waters affect the levels of concentration of this radionuclide
in the east part of the Mediterranean Sea. We also study the influence of atmospheric processes and water exchange through
Bosporus on the radioecological situation in the east part of the Mediterranean Sea and its coastal area.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
18.
A numerical model of baroclinic circulation based on the use of a double sigma coordinate system is presented and its application
to the simulation of flows and temperature and salinity fields in the Dnieper-Bug Estuary is described. The model reproduces
the salinity and temperature fields surveyed in 1998. The results of simulations reveal the existence of a global influence
of the relatively narrow and deep ship channel (through which Black-Sea waters can penetrate deep into the estuary) on the
transport processes.
Translated from Morskoi Gidrofizicheskii Zhurnal, No. 6, pp. 66–77, November–December, 2008. 相似文献
19.
In May 2007, the Marine Hydrophysical Institute of the Ukrainian National Academy of Sciences carried out an oceanographic
expedition in the northwest sector of the Black Sea. This expedition originates a series of surveys scheduled for this region.
It was realized within the framework of national and international projects, such as Climate, Ecoshelf, Stable Ecosystem, SESAM, ECOOP, and Oceanography. We present the data on the works carried out in this expedition and perform a brief analysis of the process of subduction
of waters on the northwest shelf. It is shown that, despite the abnormally warm preceding autumn–winter period, the wellpronounced
subduction of waters formed in the process of autumn–winter cooling was still observed over the drop of depth along the isopycnic
surfaces σt = 14.0 and σt = 14.5–14.6 in May 2007. New data on the intensity of vertical turbulent exchange over the continental slope in the northwest
part of the Black Sea are obtained. 相似文献
20.
K. A. Korotenko 《Oceanology》2017,57(3):394-401
The eddy-resolving (1/30)° version of the low-dissipative DieCAST [7] ocean circulation model is used for modeling processes of the protrusion of near-coastal anticyclonic eddies (NAEs) through the Rim Current (RC). Under mean climatic forcing, the model realistically reproduces the evolution of the Caucasian NAE (CNAE) from its generation, formation of an attached anticyclonic meander, protrusion through the RC, and, finally, to the formation of an isolated anticyclonic eddy and its dissipation within the Eastern Cyclonic Gyre of the Black Sea. The process of double protrusion of the CNAE and the Kizil-Yirmak NAE into the RC, their passages through the RC, and merging in the eastern part of the Black Sea is also considered. The modeled space-time parameters of NAE evolution agree well with satellite observations [15, 23]. 相似文献