共查询到20条相似文献,搜索用时 31 毫秒
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为了对《珠江口区域溢油应急计划》提供决策支持,在国内外相关研究成果基础上,针对珠江口海域的特点,研究开发了先进实用的"珠江口区域海上溢油动态预报信息系统",综合了三维潮流模型、三维溢油扩散模型、溢油风化模型、应急反应模型、以及电子海图、地理信息系统(GIS)、数据库等关键技术。该系统可以预测模拟并可视化显示海上溢油的漂移扩散和性质变化过程,同时显示环境敏感区和应急人员设备分布等相关信息。实际溢油应用案例表明,该系统的预报模拟结果与现场实际情况完全相符,能有效地提高海上溢油污染事故的应急决策效率。 相似文献
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Hidetaka Senga Naomi Kato Hiroyoshi Suzuki Tatsuya Akamatsu Lubin Yu Muneo Yoshie Toshinari Tanaka 《Journal of Marine Science and Technology》2014,19(1):90-102
It is important to forecast the location of oil spills to realize effective and adequate oil spill response operations when huge oil spilsl occur. In order to enhance the accuracy of oil drifting simulations, one needs to obtain the meteorological and oceanographic data around the oil slick. In general, the drifting velocity vector of an oil spill contains a wind velocity vector and a water current velocity vector. SOTAB-II was developed for autonomous tracking of oil slicks drifting on the sea surface. It is equipped with a sail whose size and direction are controllable to drift along with the oil slick autonomously. In addition, SOTAB-II transmits its location and necessary measured data around it to the land base in real-time. The results of field experiments using SOTAB-II with a cylindrical hull brought us the effectiveness of the sail and its control. However, the drifting speed of SOTAB-II was lower than a theoretical speed for the oil slick. In order to overcome this problem, SOTAB-II was redesigned. A yacht shape was adopted to reduce the hydrodynamic drag in the water in the advancing direction. Transverse stability, scales of brake board and sail, maneuverability, and performance of tracking spilled oil on the sea surface were considered in the process of the design. 相似文献
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The conservation of thermal energy equation applied to the mixed layer of the ocean, has been used to predict the sea surface temperature anomalies (SSTA) and the month-to-month changes in the Gulf of Mexico. The model includes the horizontal transport of heat by mean ocean currents and by turbulent eddies, as well as the heating by short and long wave radiation, evaporation and sensible heat given off to the atmosphere. A comparative study is carried out on the relative importance of the heating and transport terms. An objective verification of the skill of the predictions is presented for each season and for the whole period from March 1986 to February 1987. The predictions using only the heating terms have some skill over the control predictions (persistence and return to normal). The skill is substantially increased when the horizontal transport of heat by turbulent mixing is included in the model. The incorporation in the model of the Ekman wind drift current anomalies computed from the anomalous surface geostrophic wind improves appreciably the skill of the predictions in winter and fall.The mixed layer depth computed using the Kraus and Turner theory with dissipation, shows that the depths in summer and fall are shallower than in spring and winter. The effect of the shallow mixed layer depth in the model becomes apparent in summer and fall, improving the skill of the predictions in these seasons, with respect to the skill obtained using a constant mixed layer depth of 60 m.The incorporation in the model of the cooling in the mixed layer by turbulent entrainment of colder water from the thermocline, does not improve in an appreciable way the average skill of the predictions. 相似文献
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Manuel Gonzlez Luis Ferrer Adolfo Uriarte Agurtzane Urtizberea Ainhoa Caballero 《Journal of Marine Systems》2008,72(1-4):178
This contribution describes the procedure used during the Prestige oil-spillage event, by means of an Operational Oceanography System, and the behaviour of the present prediction tools (hydrodynamic and dispersion models) applied to it. The accuracy of these tools is estimated by a reanalysis of field data transmitted by a sea surface drifting buoy, released at the time of the oil spill. The numerical models applied were the Regional Ocean Modeling System (ROMS), fed by the available six-hourly NCEP atmospheric information, together with a Lagrangian Particle-Tracking Model (LPTM). ROMS has been used to estimate the current fields for the Bay of Biscay, whilst the LPTM has provided the oil spill trajectories. The results demonstrate that the accuracy of the numerical models depends upon the quality of the meteorological input data. In this case, the current fields at the sea surface, derived by ROMS, have been underestimated by the wind fields of the NCEP reanalysis data. An efficient calibration of these wind fields, with data provided by the Gascony buoy (fixed oceanic and atmospheric station), achieves more realistic looking results; this is reflected in the comparison between the buoy trajectory predicted numerically and the tracked movements of the drifting buoy. 相似文献
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A method is introduced to determine the uncertainties in the predictions of oil spill trajectories using a classic oil spill model. The method considers the output of the oil spill model as a function of random variables, which are the input parameters, and calculates the standard deviation of the output results which provides a measure of the uncertainty of the model as a result of the uncertainties of the input parameters.In addition to a single trajectory that is calculated by the oil spill model using the mean values of the parameters, a band of trajectories can be defined when various simulations are done taking into account the uncertainties of the input parameters. This band of trajectories defines envelopes of the trajectories that are likely to be followed by the spill given the uncertainties of the input.The method was applied to an oil spill that occurred in 1989 near Sines in the southwestern coast of Portugal. This model represented well the distinction between a wind driven part that remained offshore, and a tide driven part that went ashore. For both parts, the method defined two trajectory envelopes, one calculated exclusively with the wind fields, and the other using wind and tidal currents. In both cases reasonable approximation to the observed results was obtained.The envelope of likely trajectories that is obtained with the uncertainty modelling proved to give a better interpretation of the trajectories that were simulated by the oil spill model. 相似文献
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A probabilistic particle tracking model is used to simulate the oil dispersion after the Prestige wreckage. This oil spill constitutes a suitable benchmark to analyze the capabilities of a probabilistic model, since the time elapsed from wreckage to oil landing (12 days) is much longer than the reliability time associated with forecast winds, usually on the order of 3–4 days. The particle model can be run in two different modes: real time mode (when existing reliable wind fields for the event under scope) and in probabilistic mode (in absence of reliable wind fields but with historical fields corresponding to a similar period). The validity of the particle model is first evaluated in a hindcast way, running the Prestige case with the wind fields corresponding to the period November 19 to November 30, 2002, which were not available at the moment of the wreckage. Calculations show the accuracy of the model to provide the right impact point and timing. The probabilistic model is then used to simulate the same event by means of historical data. The region where the oil landed is shown to be the area with the highest probability to be impacted. 相似文献
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Air–sea flux measurements of O2 and N2 obtained during Hurricane Frances in September 2004 [D'Asaro, E. A. and McNeil, C. L., 2006. Measurements of air–sea gas exchange at extreme wind speeds. Journal Marine Systems, this edition.] using air-deployed neutrally buoyant floats reveal the first evidence of a new regime of air–sea gas transfer occurring at wind speeds in excess of 35 m s− 1. In this regime, plumes of bubbles 1 mm and smaller in size are transported down from near the surface of the ocean to greater depths by vertical turbulent currents with speeds up to 20−30 cm s− 1. These bubble plumes mostly dissolve before reaching a depth of approximately 20 m as a result of hydrostatic compression. Injection of air into the ocean by this mechanism results in the invasion of gases in proportion to their tropospheric molar gas ratios, and further supersaturation of less soluble gases. A new formulation for air–sea fluxes of weakly soluble gases as a function of wind speed is proposed to extend existing formulations [Woolf, D.K, 1997. Bubbles and their role in gas exchange. In: Liss, P.S., and Duce, R.A., (Eds.), The Sea Surface and Global Change. Cambridge University Press, Cambridge, UK, pp. 173–205.] to span the entire natural range of wind speeds over the open ocean, which includes hurricanes. The new formulation has separate contributions to air–sea gas flux from: 1) non-supersaturating near-surface equilibration processes, which include direct transfer associated with the air–sea interface and ventilation associated with surface wave breaking; 2) partial dissolution of bubbles smaller than 1 mm that mix into the ocean via turbulence; and 3) complete dissolution of bubbles of up to 1 mm in size via subduction of bubble plumes. The model can be simplified by combining “surface equilibration” terms that allow exchange of gases into and out of the ocean, and “gas injection” terms that only allow gas to enter the ocean. The model was tested against the Hurricane Frances data set. Although all the model parameters cannot be determined uniquely, some features are clear. The fluxes due to the surface equilibration terms, estimated both from data and from model inversions, increase rapidly at high wind speed but are still far below those predicted using the cubic parameterization of Wanninkhof and McGillis [Wannikhof, R. and McGillis, W.R., 1999. A cubic relationship between air–sea CO2 exchange and wind speed. Geophysical Research Letters, 26:1889–1892.] at high wind speed. The fluxes due to gas injection terms increase with wind speed even more rapidly, causing bubble injection to dominate at the highest wind speeds. 相似文献
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突发性海洋溢油事故预警应急联动机制研究 总被引:1,自引:0,他引:1
有效的溢油事故预警与应急反应不仅可以预防溢油事故所造成的各种经济和社会损失,而且对保护海洋环境、维护海洋资源的可持续利用起到重要作用。从溢油应急技术和应急管理现状入手,分析建立预警应急联动机制的必要性,探讨并建立了溢油事故预警应急联动的总体框架,提出了该机制正常运行的实施建议,以研究、补充安全管理中的不足,提高我国溢油应急的管理能力和技术水平。 相似文献
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分析油船溢油的主要原因,根据系统分析和层次分析相结合的原则建立油船溢油风险评价的多级评价指标体系,运用模糊数学中层次分析法结合对专家调查问卷的结果,综合分析给出油船溢油风险评价各指标的权重。将所建立的模型应用到实际油船,给出降低风险的措施。 相似文献
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照片尺寸为20mm*30mm;最好不用红色背景建立海面光学成像理论模型研究海洋内波是国内外有关研究机构的热点之一。文章初步讨论了太阳耀斑在光学卫星上的影响,结合海面光学可见光反射率模型,基于Cox-Munk模型计算了海面的辐亮度,并研究了海面风速、海面油膜对海面太阳辐亮度影响,并分析比较了它们的计算结果。 相似文献
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The CAMCAT oil spill forecasting system is presented in this paper, and an evaluation of the impact of errors in the forcing fields over its forecasts is carried out. The system is formed by several independent modules which provide forecasts of winds, currents and waves to an oil spill module which predicts the evolution of the spill.The typical twin-experiments experience is used paying special attention to a realistic characterization of the errors when perturbing the forcing fields. The results suggest that errors in the wind and current fields are the main limiting factor for the quality of the oil spill forecasts. The pollutant identification is also crucial to determine the final vertical position and characteristics of the product. 相似文献
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A three dimensional hydrodynamic model of the Malin-Hebrides shelf region is used to investigate the spatial variability of the wind and tidally induced residual flow in the region and the influence of flow from the Irish Sea and along the shelf edge. By this means it is possible to understand the spatial variability in the long term observed flow fields in the region and the range of driving forces producing this flow. The model uses a sigma coordinate grid in the vertical with a finer grid in the near surface and near bed shear layers. The vertical diffusion of momentum in the model is parameterised using an eddy viscosity coefficient which is derived from turbulence energy closure models. Two different turbulence models are used to compute the eddy viscosity, namely a two-equation (itq2−q2ℓ) model which has prognostic equations for both turbulence energy and mixing length and a simpler model in which the mixing length is a specified algebraic function of the water depth.The wind induced response to spatially and temporally constant orthogonal wind stresses, namely westerly and southerly winds of 1 N m−2, are derived from the model. By using orthogonal winds and assuming linearity, then to first order the response to any wind direction can be derived. Computed flows show a uniform wind driven surface layer of magnitude about 3% of the wind speed and direction 15 ° to the right of the wind, in deep water. Currents at depth particularly in the shelf edge and near coastal region show significant spatial variability which is related to variations in bottom topography and the coastline.Calculations show that tidal residual flows are only significant in the near coastal regions where the tidal current is strong and exhibits spatial variability. Flow into the region from the Irish Sea through the North Channel although having its greatest influence in the near coastal region, does affect currents near the shelf edge region. Again the spatial variability of the flow is influenced by topographic effects.A detailed examination of wind induced current profiles together with turbulence, mixing length and viscosity, at a number of locations in the model from deep ocean to shallow near coastal, shows that both turbulence models yield comparable results, with the mixing length in the two equation model showing a similar dependence to that specified in the simpler turbulence model.Calculations clearly show that flow along the shelf edge area to the west of Ireland and from the Irish Sea entering the region, together with local wind forcing can have a major effect upon currents along the Malin-Hebrides shelf. The flow fields show significant spatial variability in the region, comparable to those deduced from long term tracer measurements. The spatial variability found in the calculations suggests that a very intense measurement programme together with inflow measurements into the area is required to understand the circulation in the region, and provide data sets suitable for a rigorous model validation. 相似文献
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The behavior of the flow passing a tandem oil fence, and the performance of the fence, were investigated by experimental and numerical methods. The flow characteristics between tandem fences were measured by the particle image velocimetry (PIV) method for the rigid and open free surface between the two fences in order to gather reference data for numerical investigations. A method of assessing a tandem fence by tracing the movement of an oil droplet around the fence is introduced. The effect of the current speed, the separation distance between the two fences, the relative draft of the two fences, and the water depth on the oil containment between the fences was investigated. 相似文献