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1.
A three-dimensional nonlinear mathematical model is used to study the dynamic processes under the action of cyclonic disturbances in the field of stationary wind in the Sea of Azov and the specific features of transformation of the impurities. The results of numerical calculations enable us to conclude that the maximum velocities of currents generated by a cyclone depend on the direction of its motion. It is shown that the cyclones moving westward generate currents with higher maximum velocities than the cyclones of other directions. It is also demonstrated that the motion of atmospheric disturbances leads to a significant enlargement of the area of propagation of pollutants as compared with the case of action solely of stationary currents. The influence of the velocities of stationary currents on the maximum current velocities caused by the passage of a cyclone is also analyzed.  相似文献   

2.
In this model, we apply a nonlinear three-dimensional sigma-coordinate model to study the waves and currents in the Sea of Azov generated by different fields of wind forcing: a constant wind, a quickly varying real wind obtained using the data of reanalysis applying the SKIRON model, and the wind resulting from their combined forcing. This mathematical model was also applied to study the transformation of the passive admixture appearing under the influence of wind fields in the Sea of Azov considered here. We compared the results of numerical calculations with the field data obtained under the wind forcing at a number of hydrological stations. We found the regularities of the water transport driven by onshore and offshore winds, the velocities of the currents, and the characteristics of the evolution of polluted regions at different depths as functions of the nonstationary wind intensity and the velocities of the stationary currents.  相似文献   

3.
By the method of numerical modeling, we study the influence of the velocity of constant wind on the currents and oscillations of level in the Azov Sea. A three-dimensional nonlinear numerical model is applied to determine the regions characterized by the maximum and minimum values of the velocities of surface stationary currents and the highest deviations of level in the open part of the Azov Sea. In the presented maps, we indicate the points of the water area, where the extreme values of deviations of the sea level and the highest current velocities are attained. We analyze the influence of the velocity of constant wind on the time of attainment of the extreme values of elevations and lowerings of the sea level and current velocities.  相似文献   

4.
Using a three-dimensional nonlinear mathematical model, we study the processes of transfer and diffusion of contaminants in the Sea of Azov in the presence of stationary currents. Changes in the sea level, surge phenomena, and the direction and velocity of stationary currents caused by winds with different maximum velocities are analyzed. We estimate the region of applicability of the linear approximation and the choice of the value of integration steps over space and time coordinates. It is shown that the growth of the maximum wind velocity increases the contaminated domains and the time of complete dispersion of the admixture. Solutions obtained in the linear approximation differ slightly from those obtained by using the nonlinear model for wind velocities up to 5 m/sec. Translated from Morskoi Gidrofizicheskii Zhurnal, No. 4, pp. 52–68, July–August, 2008.  相似文献   

5.
We present the results of numerical modeling of the influence of water exchange through the Kerch Strait on the stationary motions in the Azov Sea. We use a three-dimensional nonlinear numerical model to perform the analysis of extreme deviations of the sea level and the surface and deep-water currents depending on the direction and velocity of constant wind with and without regard for the water exchange through the strait. It is shown that the influence of water exchange with the Black Sea leads to the increase in the maximum deviations of the sea level and the velocities of stationary currents. Thus, in particular, it is shown that, for a wind velocity of 10 m/sec, the maximum values of the surge and current velocities in the presence of the strait are higher than in the absence of the strait by 36 and 42%, respectively. In this case, the highest current velocities are induced by the south wind.  相似文献   

6.
The effect of seawater movement through the Kerch Strait for extreme deviations in the level and speed of currents in the Sea of Azov caused by the action of climate wind fields has been studied using the Princeton ocean model (POM), a general three-dimensional nonlinear model of ocean circulation. Formation of the water flow through the strait is caused by the long-term action of the same type of atmospheric processes. The features of the water dynamics under conditions of changing intensity and active wind direction have been studied. Numerical experiments were carried out for two versions of model Sea of Azov basins: closed (without the Kerch Strait) and with a fluid boundary located in the Black Sea. The simulation results have shown that allowance for the strait leads to a significant change in the velocities of steady currents and level deviations at wind speeds greater than 5 m/s. The most significant effect on the parameters of steady-state movements is exerted by the speed of the wind that generates them; allowance for water exchange through the strait is less important. Analysis of the directions of atmospheric circulation has revealed that the response generated by the movement of water through the strait is most pronounced when a southeast wind is acting.  相似文献   

7.
ModellingofthebarotropicprocessesintheBohaiSea¥HuangDaji;ChenZongyongandSuJilan(SecondIngtituteofOceanography,StateOceanicAdm...  相似文献   

8.
渤海及黄海北部的风海流数值计算及余流计算   总被引:1,自引:1,他引:1  
依据黄渤海实测风的资料对渤海及北黄海进行了月平均风海流数值计算。计算表明 ,1月份在西北风的作用下 ,在渤海出现 1个逆时针旋转的环流 ,在辽东湾北部及黄海北部出现 1个顺时针旋转的环流 ,渤海海峡的海流北进南出。 7月份在南风和东南风的作用下 ,风海流的变化形式与 1月份大致相反 ,海峡处呈南进北出的形式。对渤海中部某点 1年的潮流资料通过低通滤波的方法计算逐时的余流值 ,得到该点 1年内表层最大的实测余流为 31.9cm/ s,全年 90 %多的时间内表层余流小于 10 cm/ s。对辽东湾北部某点和渤海湾西南部某点数月潮流资料也进行了低通滤波 ,并将得到的逐时余流与同步风作了比较。依据该 2点风和余流的关系以及黄海北部 6个点风和余流的关系验证了风海流数值计算的结果 ,表明在这些点上实测与计算结果拟合良好  相似文献   

9.
We present the results of numerical simulation of currents and sea level for the Sea of Azov. In calculations, we use a three-dimensional nonlinear mathematical model taking into account the tangential wind stresses. We present the results of numerical analysis of the fields of currents and the amplitudes of oscillations of the sea level at the coastal stations as functions of the maximum velocity and the period of constant action of the west wind. __________ Translated from Morskoi Gidrofizicheskii Zhurnal, No. 1, pp. 12–25, January–February, 2008.  相似文献   

10.
We discuss the results of numerical experiments modelling the process of propagation of passive impurities from the Karantinnaya Bay caused by steady wind currents and turbulent diffusion. The currents are computed according to the Felzenbaum model for the cases of northeast and north-west winds [1, 2]. We analyse specific features of the space and time distribution of the impurities caused by the three-dimensional character of the currents. Translated by Peter V. Malyshev and Dmitry V. Malyshev  相似文献   

11.
The currents and surface level oscillations in the Sea of Azov ensuing from contraction of the mouth of Taganrog Bay are computed using the grid technique on the basis of a numerical solution to the system of quasi-linear, degenerate, parabolic, partial derivative equations (shallow-water equations). It is demonstrated what changes are to be expected in the dynamics of the Sea of Azov should this project be realized. The computations were carried out for typical wind directions.Translated by Vladimir A. Puchkin.  相似文献   

12.
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   

13.
Diurnal wind (DW) and nonlinear interaction between inertial and tidal currents near the Xisha Islands of the South China Sea (SCS) during the passage of Typhoon Conson (2010) are investigated using observational data and a damped slab model. It is found that the DWs, which are dominated by clockwise wind components, are prominent at our observational site. The DWs increase after the passage of the typhoon from 1 to about 4 m/s, which may be due to the decrease of the sea surface temperature caused by the passage of the typhoon. Kinetic energy spectra and bicoherence methods reveal nonlinear interactions between the inertial currents and the 2MK3 tidal constituent at our observational site. The slab damped model reproduces the inertial currents successfully induced by the total observed winds, and it is shown that the inertial currents induced by DWs are positively proportional to the DWs speed. Even though the observed inertial currents are distinct, the proportion of inertial currents induced by DWs to those induced by the total observed winds is just 0.7%/4% before/after the passage of typhoon. This shows that the inertial currents induced by the DWs are unimportant near the Xisha Islands during the typhoon season.  相似文献   

14.
The Chukchi and Beaufort Seas include several important hydrological features: inflow of the Pacific water, Alaska coast current ( ACC ), the seasonal to perennial sea ice cover, and landfast ice 'along the Alaskan coast. The dynamics of this coupled ice-ocean system is important for both regional scale oceanography and large-scale global climate change research. A mumber of moorings were deployed in the area by JAMSTEC since 1992, and the data revealed highly variable characteristics of the hydrological environment. A regional high-resolution coupled ice-ocean model of the Chukchi and Beaufort Seas was established to simulate the ice-ocean environment and unique seasonal landfast ice in the coastal Beaufort Sea. The model results reproduced the Beaufort gyre and the ACC. The depthaveraged annual mean ocean currents along the Beaufort Sea coast and shelf hreak compared well with data from four moored ADCPs, but the simulated velocity had smaller standard deviations, which indicate small-scale eddies were frequent in the region. The model resuits captured the sea,real variations of sea ice area as compared with remote sensing data, and the simulated sea ice velocity showed an ahnost stationary area along the Beaufort Sea coast that was similar to the observed landfast ice extent. It is the combined effects of the weak oceanic current near the coast, a prevailing wind with an onshore component, the opposite direction of the ocean current, and the blocking hy the coastline that make the Beaufort Sea coastal areas prone to the formation of landfast ice.  相似文献   

15.
2007年在朱家尖和嵊山布设了小型阵变频高频地波雷达,对共同覆盖范围内的舟山海域进行风、浪、流的业务化探测。2015年7月11日,1509号台风灿鸿在朱家尖沿海登陆,之后继续向北偏东方向移动,台风中心经过高频地波雷达探测海域。本文将台风期间高频地波雷达的探测数据分别与定点浮标观测数据和ASCAT卫星遥感大面积风场数据进行了对比分析。结果表明,高频地波雷达在台风期间较好地反映了舟山海域流场特征和风场分布情况,高频地波雷达的探测数据精度满足指标要求,验证了高频地波雷达在复杂海况条件下具有合格的探测性能。  相似文献   

16.
Wind-velocity data obtained from in situ measurements at the Golitsyno-4 marine stationary platform have been compared with QuikSCAT scatterometer data; NCEP, MERRA, and ERA-Interim global reanalyses and MM5 regional atmospheric reanalysis. In order to adjust wind velocity measured at a height of 37 m above the sea surface to a standard height of 10 m with stratification taken into account, the Monin–Obukhov theory and regional atmospheric reanalysis data are used. Data obtained with the QuikSCAT scatterometer most adequately describe the real variability of wind over the Black Sea. Errors in reanalysis data are not high either: the regression coefficient varies from 0.98 to 1.06, the rms deviation of the velocity amplitude varies from 1.90 to 2.24 m/s, and the rms deviation of the direction angle varies from 26° to 36°. Errors in determining the velocity and direction of wind depend on its amplitude: under weak winds (<3 m/s), the velocity of wind is overestimated and errors significantly increase in determining its direction; under strong winds (>12 m/s), its velocity is underestimated. The influence of these errors on both spatial and temporal estimates of the characteristics of wind over the Black Sea is briefly considered.  相似文献   

17.
In this paper the wind-wave variability in the tidal basins of the German Wadden Sea is modelled with combined numerical and neural-network (NN) methods. First, the wave propagation and transformation in the study area are modelled with the state-of-the-art third-generation spectral wave model SWAN. The ability of SWAN to accurately reproduce the phenomena of interest in nonstationary conditions governed by highly variable winds, water levels and currents is shown by comparisons of the modelled and measured mean wave parameters at four stations. The principal component analysis of the SWAN results is then used to reveal the dominating spatial patterns in the data and to reduce their dimensionality, thus enabling an efficient and relatively straightforward NN modelling of mean wave parameters in the whole study area. It is shown that the data produced with the approach developed in this work have statistical properties (discrete probability distributions of the mean wave parameters etc.) very close to the properties of the data obtained with SWAN, thus proving that this approach can be used as a reliable tool for wind wave simulation in coastal areas, complementary to (often computationally demanding) spectral wave models.  相似文献   

18.
Seiche oscillations of the Azov Sea level are studied on the basis of the developed two-dimensional numerical hydrodynamic model grounded on the shallow water theory and recent data on the morphometric characteristics of the Sea of Azov. Frequency and spatial characteristics of the first five modes corresponding to seiche oscillations of the Azov Sea level are computed. It is shown that the frequency and spatial characteristics of the first five modes obtained for the Sea of Azov level changes correspond to seiche oscillations. The calculated parameters are compared with the field observations, which show their realistic character.  相似文献   

19.
This study investigates atmospheric responses to the directions of surface wind over the Kuroshio front in the East China Sea, using wintertime satellite-derived data sets. Composite maps of sea surface temperature, wind speed, precipitation, turbulent heat flux, surface wind divergence, and the curl of wind vectors above the atmospheric boundary layer are depicted based on the classification of intense northeasterly (along the front) and northwesterly (across the front) winds over the East China Sea. When northeasterly winds prevail, considerable precipitation occurs on the offshore side of the Kuroshio front, in contrast to periods when northwesterly winds prevail. First, the northeasterly winds strengthen above the front because of the downward transfer of momentum from the fast-moving air at higher levels and/or an adjustment of sea level pressure over the oceanic front, although the process by which the influence of the Kuroshio penetrates beyond the marine atmospheric boundary layer remains unclear. Second, a cyclonic vortex forms above the marine atmospheric boundary layer (at 850-hPa height) on the offshore side of the front, and thereafter, surface wind convergence via Ekman suction (hence, enhanced precipitation) occurs over the East China Sea shelf breaks. The northeasterly winds blow over the East China Sea when the Aleutian Low retreats to the east and when high sea level pressure covers the northern Sea of Japan.  相似文献   

20.
The prognostic fields of the surface winds and atmospheric pressure obtained according to the data of the Skiron prognostic system are used to study the surge phenomena in the Azov Sea by using a three-dimensional nonlinear model. The accumulated numerical results are compared with the data of direct measurements of the sea level at the coastal stations. The degree of sensitivity of the computed levels of surges to the value of the coefficient of surface friction is evaluated. Translated from Morskoi Gidrofizicheskii Zhurnal, No. 6, pp. 53–65, November–December, 2008.  相似文献   

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