渤海溢油三维漂移数值模拟研究

国家海洋局北海预报中心于2011年开发了渤海三维溢油模型,该模型在分析国内外溢油模型现状的基础上,借鉴当今流行的数值模拟方法,使用油粒子模型与油膜扩展模型相结合的方式,用拉格朗日方法追踪每个带有一定油量的油粒子的轨迹,针对每一个油粒子则使用油膜扩展理论计算其油膜扩展过程。该模型可实现对溢油油污上升及水平输运过程、海表面油污浓度的预报,通过三组理想试验和2012年的海上溢油实验数据,对模型的各项功能、稳定性及模型精度进行了对比验证,结果较好,模型可实现对渤海海域海底或水下发生溢油的数值模拟。该模型解决了以往二维溢油模型在模拟钻井平台及海底输油管道泄漏等溢油事故方面的不足,可更好地为溢油灾害对海洋环境影响的估计提供有效参考信息。     

溢油模型与SSD曲线法评估渤海溢油事件的海洋生态风险

海上溢油事故不仅会造成大面积的海水污染,还会对海洋生态系统造成严重破坏。为此,采用有效的方法评估溢油事件引起的生态风险,对防灾减灾工作具有重要意义。本文以发生于2011年6月的渤海蓬莱19-3溢油事故为例,使用两种溢油模型(GNOME轨迹模型与ADIOS风化模型)模拟了事故初期油膜的运动轨迹与风化过程。基于模拟结果,利用CAFE模型(Chemical Aquatic Fate and Effect)拟合了相应的物种敏感度分布(species sensitivity distribution,SSD)曲线,首次结合三种模型工具对渤海进行了生态风险评估研究。结果显示,随着原油的持续泄漏,其主要有毒物质(苯系物)浓度达到了1 300μg/L,超过了1%危害浓度值(Hazard Concentration 1%,HC1)。结果表明,在事故初期所产生的生态风险不可忽视,并且风险(多个物种的潜在影响分数)会在96 h内以每日约1%的趋势增长。本文结合溢油运动轨迹和SSD曲线,绘制出了事故期间的生态风险时空分布图。经过定量化的评估,首次发现事故的整体生态风险随时间呈近似二次函数增长,同溢油轨迹一样,向西北方向扩散,越靠近溢油源的海域生态风险概率越高。     

Particle tracking experiments on a model of the Okhotsk Sea: Toward oil spill simulation

Particle tracking experiments were conducted for the Sea of Okhotsk using a three-dimensional ocean circulation model, as a step toward the simulation of oil spills. The model’s reproducibility is first examined in detail. Comparison with surface drifter and moored ADCP data shows that the model successfully reproduces the velocity field over the shelves, particularly in the weak stratification period. This is because the current variability is simply determined by integration of the alongshore component of the wind stress over the coast from which arrested topographic waves propagate. Good agreement even in the ice-covered period implies that the neglect of sea ice in the model is not a problem for reproduction of the current over the shelves. Good agreement also supports the correction of ECMWF wind speed by a factor of 1.25. A series of particle tracking experiments was carried out to examine the case of particles released from the Sakhalin oil field at depths of 0 m and 15 m. Regardless of the deployment month and year, most particles at depth 15 m are transported southward along the Sakhalin coast, in accordance with the abrupt intensification of the East Sakhalin Current in October, finally arriving offshore of Hokkaido in November–January. Particles at the surface, which are affected by wind drift in addition to the ocean current, show larger yearly variability. In years when the offshoreward-wind dominates, the particles would be advected out of the mainstream of the current and would not be transported offshore of Hokkaido.     

The error source analysis of oil spill transport modeling: a case study

Numerical modeling is an important tool to study and predict the transport of oil spills. However, the accu- racy of numerical models is not always good enough to provide reliable information for oil spill transport. It is necessary to analyze and identify major error sources for the models. A case study was conducted to analyze error sources of a three-dimensional oil spill model that was used operationally for oil spill forecast- ing in the National Marine Environmental Forecasting Center （NMEFC）, the State Oceanic Administration, China. On June 4, 2011, oil from sea bed spilled into seawater in Penglai 19-3 region, the largest offshore oil field of China, and polluted an area of thousands of square kilometers in the Bohai Sea. Satellite remote sensing images were collected to locate oil slicks. By performing a series of model sensitivity experiments with different wind and current forcings and comparing the model results with the satellite images, it was identified that the major errors of the long-term simulation for oil spill transport were from the wind fields, and the wind-induced surface currents. An inverse model was developed to estimate the temporal variabil- ity of emission intensity at the oil spill source, which revealed the importance of the accuracy in oil spill source emission time function.     

渤海海域多源遥感溢油风险评价与长序监测

渤海海域溢油事件频发,所以进行海洋溢油风险时空特征分析,对于开展卫星遥感溢油精确监测具有重要意义.作者采用多源高分辨率卫星遥感数据,提取渤海海域船舶及石油平台两类主要溢油风险源分布状况,结合2015—2020年间渤海海域海上溢油卫星遥感监测结果,分析多种传感器下不同类型溢油的成像特征,通过溢油风险源核密度分析方法,获得...     

同化技术在渤海溢油应急预报系统中的应用

溢油应急预报对溢油事故现场处理具有重要指导意义。国内外已开展大量溢油数值预报技术研究,但由于各类误差的引入(尤其风和流数值预报误差的引入)以及模型本身的不完善等各种原因导致溢油数值预报无法满足日益提高的溢油预报精度需求。随着现场观测技术和监测水平的提高,如何充分利用实时观测数据提高业务化溢油应急预报精度,并满足应急预报迅速快捷的要求,成为目前业务化溢油应急预报的首要问题。国家海洋环境预报中心于2008年实现了渤海溢油业务化预报系统的建立和业务化应用,本文针对当前渤海溢油业务化应急预报中存在的现实问题,利用已有渤海海上5个石油平台从2010年1月至2011年2月的风场观测数据,初步开展最优插值方法(optimal interpolation assimilation method,OI)同化技术在国家海洋环境预报中心渤海溢油应急预报系统风场订正的应用研究。本文采用交错订正方法,确定了OI同化技术中相关尺度因子的选取,从而实现在这5个观测站地理分布情况下,OI同化技术应用中参数的最优化,之后在理想实验和实际案例的应用中,该同化方法明显提高渤海溢油预报精度。本文为如何进一步利用同化方法迅速快捷地实现溢油应急预报精度的提高提供了一定研究基础。     

A quasi-three-dimensional numerical prediction model of salinity structure in Bohai Sea and Huanghai Sea

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渤海海上溢油漂移扩散数值模拟研究

近几年渤海海上溢油突发事件频发,对海洋环境造成严重的污染。本文将业务化气象数值模型(Weather Research and Forecast model,WRF)、海流数值模型(Regional Ocean Model System,ROMS)的数值预报结果作为海洋环境驱动场,采用"油粒子"的海上溢油漂移扩散数值模拟方法,对在渤海发生的溢油扩散行为进行模拟预测。本文针对渤海溢油事件,设计敏感试验,研究不同风、流系数和网格分辨率对溢油扩散模拟结果的影响,获得适合于渤海的溢油数值模型参数,提高溢油漂移扩散预报的准确度,为海洋溢油应急处置和防灾减灾提供技术支持。     

基于GF-1卫星的海上溢油定量监测——以青岛溢油事故为例

基于GF-1卫星数据对2013年11月22日青岛黄潍输油管道爆炸造成的海面溢油进行定量监测。研究首先采用2013年11月26日GF-1卫星数据对海面溢油进行提取,其统计面积为0.67 km2;其次,结合肖剑伟提出的油膜厚度单波段反演模型估算油膜厚度,最终计算得到溢油量为0.28 t;最后,对Band 1反射率与油膜厚度结果进行灰度分割,将溢油污染程度分为6级,对比发现两者分级结果较为一致。由此得出,通过反射率直接进行灰度分割可以对溢油污染进行有效的等级评定。     

Wrench-related folding: A case study of Bohai Sea basin,China

Wrench motion is relatively common in basins but often goes undetected because of its subtle structural imprint. Even so wrench-related folding is of significance in petroleum exploration and development. Based on the Riedel shear nomenclature, we apply the model of wrench-related folding to deformation in the Bohai sea basin. The folding related to R-shears, T-tensional structural systems (T-systems) and C-compressive structural systems (C-systems) in a Riedel shear model are discussed. The R-system related folding results from differential movements between the two sides of fault blocks, in map view the fold is oriented (90°-φ/2) (in the initial deformation stage) or more than (90°-φ/2) from the principle displacement zone (PDZ), where φ is the angle of internal friction. The T-system related folding is related to the rollover of the hanging wall, and in map view the fold is initiated at 45° from the PDZ in the initial deformation stage. The C-system related folding is resulted from the compression induced by a wrench action, in map view the fold was oriented 45° from initial deformation in the PDZ. Bohai Sea basin fold orientations fit our models, and the wrench-related folds play important roles in oil and gas accumulation.     

A numerical model study of the Alboran Sea Gyre

Reduced gravity and two-layer numerical models have been used to study the circulation in the westernmost basin of the Mediterranean Sea, the Alboran Sea. Circulation is forced by flow through a 20 km wide port in the western boundary representing the Strait of Gibraltar.The reduced gravity model domain is a rectangle measuring 600 km × 160 km with 10 km × 5 km grid resolution. When forced by an eastward on northeastward inflow, the model solutions evolve to a steady state which exhibits a meandering current. The first meander of the current forms the northern boundary of an anticyclonic gyre. Horizontal dimensions of the gyre are strongly dependent upon the inflow angle, vorticity associated with the incoming current, magnitude of the incoming transport and the north-south extent of the basin. The meandering current is considered a standing Rossby wave with a highly distorted vorticity trajectory due to the interaction of the current with the northern and southern boundaries. When velocity (transport) is increased, the wavelength increases approximately as √v. As a result the anticyclonic gyre shifts east as velocity increases and west as velocity decreases. These solutions show that bottom topography, winds and coastline features are not necessary mechanisms for the formation of the gyre.Two-layer model solutions were obtained using realistic topography, geometry and a westward moving lower layer. The addition of the lower layer flow and topography distorted the circulation in the upper layer, particulary in the southern half of the basin. This is caused by the large topographically steered currents along the southern shelf.The high variability of the horizontal dimensions and location of the gyre has been observed both experimentally and through satellite imagery. Model results show that the high variability is caused by variations in the inflow velocity.Drifter tracks, both observational and model derived, help determine the circulation in both layers of the Alboran Sea. The close comparison between model and experimental drifters lends credibility to the model circulation and dynamics.     

海洋溢油溯源数值模拟方法的研究进展

海洋溢油溯源数值模拟可以为海上溢油事故的应急处置提供技术支撑,同时对确定溢油事故的泄漏源和责任方也具有重要的指导意义。本文概述了海洋溢油溯源数值模拟方法的最新研究成果,总结分析了包括对流扩散过程的逆运算、受体模式、粒子追踪模式和垂向溯源方法等在内的四类数值模拟方法的基础理论和研究进展。同时,归纳了三种常用的溢油溯源数值模拟结果分析方法,并给出了每种方法的优缺点及其对应的适用条件。在分析海洋溢油溯源数值模拟方法应用现状的基础上,初步探讨面临的挑战。这对全面理解溢油溯源数值模拟方法的理论和应用提供了重要参考,并可为相关工作和后续数值模拟方法的改进奠定基础。     

海上溢油数值模型研究进展

我国是海洋大国,近年来,海上活动持续增多,发生海上溢油事故的风险随之加大,海上溢油污染事故一旦发生,如不得到及时控制,必将严重损害我国近海海洋环境。为了完善我国海上溢油应急反应体系,提高我国处理重大海上溢油事故的应急反应能力,海上溢油污染应急技术研究已经得到开展。本文综述了溢油预测模型的发展过程以及相关的研究成果,包括：溢油扩展模型、溢油漂移模型、油粒子模型和溢油风化模型等。这为进一步开展溢油预测和溢油污染应急工作提供了理论依据和参考。     

基于元胞自动机的海洋溢油模型

本文采用三维元胞自动机模型,对海洋溢油过程进行了模拟,对风流、水流等水平方向的影响系数进行了改进。考虑了蒸发、垂直扩散、岸边附着、溶解、乳化等因子的影响,并且引入乳化含水率将乳化因子进行实际量化,构建了海洋溢油模型。并以"Deep Spill"的溢油实验为基础进行了模拟,实验结果 Kappa系数达到0.902,与实际相比具有较好的一致性。本文对海洋溢油事故进行预测模拟,为提出合理有效的应急预案提供科学依据。     

海上溢油数值模型研究进展

中国是海洋大国,近年来,海上活动持续增多,发生海上溢油事故的风险随之加大,海上溢油污染事故一旦发生,如不得到及时控制,必将严重损害中国近海海洋环境.为了完善中国海上溢油应急反应体系,提高中国处理重大海上溢油事故的应急反应能力,开展了海上溢油污染应急技术研究.本文综述了溢油预测模型的发展过程以及相关的研究成果,包括:溢油...     

2011年6月-8月渤海湾溢油事故长期后报数值模拟

三维业务化溢油应急预报系统不仅能提供逐时的海洋环境信息预报和溢油漂移扩散,还能对溢油事件进行后报数值模拟。2011年6月4日在渤海湾蓬莱19-3B采油平台发生溢油事件,同月17日19-3C平台也发生溢油事件。此次溢油事故造成了数千平方公里海水受污染。本文采用国家海洋环境预报中心自主研发的溢油模型对蓬莱19-3溢油事件进行长期后报数值模拟,在风流海洋环境场的驱动下,模拟了2016年6月到2016年8月,两个平台溢油的漂移扩散情况、影响范围,靠岸时间和影响岸段等。风场采用基于WRF模型模拟得到的再分析风场,并用实测风对再分析风场进行订正,流场采用基于POM模式在再分析风场驱动下得到的海流。后报结果显示,溢油主要向西北方向漂移,并最终靠岸,其扫过的海域也主要在平台的西北方向,这与观测结果一致,验证了后报的可靠性。     

渤海海冰季节演变的数值模拟

MM5数值产品作为大气强迫,利用冰-海洋耦合模式模拟2003～2004冬季渤海海冰演变过程。与海冰遥感、海洋站监测资料等实测资料相比,初冰日和终冰日和观测数据比较接近,模拟海冰各个发展阶段主要分布特征和MODIS遥感图像相似,但模拟的海冰厚度与辽东湾93平台、202平台的冰厚观测数据相比存在较大出入,说明该模型还有待改善。总体上看,冰-海洋耦合模式基本具备模拟渤海海冰季节演变过程的能力。     

The influence of Stokes drift on oil spills: Sanchi oil spill case

Spilled oil floats and travels across the water’s surface under the influence of wind, currents, and wave action. Wave-induced Stokes drift is an important physical process that can affect surface water particles but that is currently absent from oil spill analyses. In this study, two methods are applied to determine the velocity of Stokes drift, the first calculates velocity from the wind-related formula based upon a one-dimensional frequency spectrum, while the second determines velocity directly from the wave model that was based on a two-dimensional spectrum. The experimental results of numerous models indicated that: (1) oil simulations that include the influence of Stokes drift are more accurate than that those do not; (2) for medium and long-term simulations longer than two days or more, Stokes drift is a significant factor that should not be ignored, and its magnitude can reach about 2% of the wind speed; (3) the velocity of Stokes drift is related to the wind but is not linear. Therefore, Stokes drift cannot simply be replaced or substituted by simply increasing the wind drift factor, which can cause errors in oil spill projections; (4) the Stokes drift velocity obtained from the two-dimensional wave spectrum makes the oil spill simulation more accurate.     

黄渤海精细化温带风暴潮数值预报模式研究及应用

该文基于ELCIRC(3D Eulerian-Lagrangian Circulation)海洋模型建立了一套适合黄渤海高分辨率的温带风暴潮数值预报模式。该模式基于非结构三角形网格,对岸形的刻画具有较好的能力;利用该模式对2009年2次显著温带风暴潮过程进行了分析与数值模拟,将模拟结果与受影响的几个验潮站的实测数据进行了对比;对比结果表明:所建立的高分辨率预报模式后报效果总体良好;对模式中存在的问题以及造成误差的因素进行了分析说明。