轨迹烟流模式计算方法

集合了高斯烟流模式和烟团模式的优点,提出一个新的模型———轨迹烟流模式,既保留了烟流模式计算简单,计算结果连续的特点,又可以根据当时风场,确定不同的烟流轨迹,模拟烟团的弯曲、折回和重叠运动,分段进行计算,提高了计算的准确性扩大了模式应用范围。     

城区大气污染物—NOx浓度预测预报模式研究

利用道路边大气污染的常年监测数据，对风向与无限线源成任意角的高斯内插大气扩散模式进行了系统测试，分析了影响预报精度的主要因素，在分析武汉市气象因素和天气状况的基础上，对模式进行了恰当地修正，经实测数据验证，预报准确度有了明显地提高。     

城郊中型热浮力烟流的铅直扩散特征

本文用立体摄影的方法研究了济南城郊中型热浮力烟流的铅直扩散特征。结果表明,城郊铅直扩散参数相当于P—G参数向不稳定方向提1～1.5级后的扩散参数;在近源处,热浮力烟流的铅直扩散能力受自生湍流作用影响较大,自生湍流的作用随距离的增加而减小,且在近源处,自生湍流的作用随大气稳定程度的增加而增加。 ·     

天津市大气主要污染物总量控制允许排放量实施方案

本文采用环境质量总量控制技术路线。在天津市建立了１８个总量控制区,利用箱扩散模型（Ａ值法）测算了各总控区二氧化硫的允许排放量。利用Ｐ值法将区域允排量分配到源。本文还将化学质量受体平衡（ＣＭＢ）模型纳入Ａ－Ｐ值模型,形成ＡＰ－ＣＭＢ模型,用以测算烟尘和工业粉尘的区域允排量将将分配到源。由此构成天津市大气主要污染物总量控制允排量实施方案。     

复杂地形城市SO2扩散特征的模拟研究

利用中尺度气象模式RAMS和大气扩散模式HYPACT,结合甘肃省-中科院科技合作项目"兰州市大气污染及对策研究"于2000年12月在兰州市城区进行的大气污染物监测资料,通过资料分析与模拟计算,研究了兰州市冬季SO2的扩散特点。研究结果表明:大气扩散模式较好地模拟出了SO2时空分布特征,与同期监测资料的分析结果比较一致,模式模拟的SO2浓度分布的日变化与环流场的日变化紧密相关;模拟的SO2浓度的空间分布与污染源的排放方式有关,污染源的排放高度不同,造成污染的高度也不同,高架源对地面的影响比较小,而中、低架源对地面的影响比较大。     

中国生态系统研究网络中农业生态系统水平衡水循环研究的方向…

阐述了农业生态水平衡水循环研究的方向是研究农田土壤－植物－大气系统的水分交换及其在生产实践中的作用和理论上的意义，其研究任务可分四个层次：（１）在试验站综合观测场进行点的试验；（２）在生态系统优化模式的试验示范区进行小区，小流域的试验；（３）在更大的生态类型区域内进行更全面，更复杂问题的研究；（４）在区域研究的基础上对不同生态类型地区水平衡水循环进行联网研究，作者认为，在ＣＥＲＮ中应重视有关农业生     

长江镇江段COD排放量控制的环境效益分析

在镇江金东造纸工程环境影响评价中，提出了长江镇江段全江段ＣＯＤ排放量控制方案，通过模式进行分段定量计算，分析了工程实施所造成的环境损失和实施区域排放量控制所产生的环境效益。     

天津城市热岛及其对污染物扩散影响的数值模拟

城市热岛直接影响城市风场结构和污染物扩散路径,以能量平衡模式得到的地面温度作为下边界条件、中尺度气象模式MM5作初始场和侧边界条件,建立了天津市500 m的细网格城市边界层模式并用其研究天津市秋季热岛及其对污染物扩散的影响.结果表明,模式可以较好地模拟城市热岛现象,地面温度日变化规律及近地层的温度廓线与实际观测值较一致,能够反映夜间出现的逆温.模式成功地再现了城市温度场和流场的三维结构,结果表明17:00时热岛强度在地面最强,到300m存在个别的弱热岛中心,500m高度城郊不存在温度差异;地面高温中心有一个弱的辐合中心,直接影响污染物在城区的扩散,模拟的污染物浓度在地面较低,150～300 m高度最大.该研究结果可为了解天津地区局地气候的形成、污染物的扩散及城市规划提供参考和帮助.     

游蛇科4种的核型比较

以骨髓细胞直接制备染色体标本，分析了游蛇属（Ｎａｏｔｒｉｘ）３种和链蛇属（Ｄｉｎｏｄｏｎ）１种蛇的核型．草游蛇（Ｎ．ｓｔｏｌａｔａ）２ｎ＝３６，１８（１５Ｍ＋１ＳＴ＋２Ｔ）·１８ｍ（♀）．渔游蛇（Ｎ．Ｐｉｓｃａｔｏｒ）２ｎ＝４０，１６（１０Ｍ＋１ＳＭ＋３ＳＴ＋２Ｔ）·２４ｍ（♀）．乌游蛇（Ｎ．ｐ．ｐｅｒｃａｒｉｎａｔａ）２ｎ＝４０，１８（８Ｍ十２ＳＭ＋８Ｔ）·２２ｍ（♂）．赤链蛇（Ｄ．ｒｕｆｏｚｏｎａｔｕｍ）２ｎ＝４６，２０（１Ｍ＋３ＳＭ＋１６Ｔ）·２６ｍ（♀）．草游蛇和渔游蛇的Ｎｏｓ，赤链蛇的Ｎｏ３为ＺＺ／ＺＷ型性染色体．草游蛇Ｚ染色体为Ｍ型，Ｗ染色体为ＳＴ型；渔游蛇Ｚ为ＳＭ型，Ｗ也是ＳＴ型；赤链蛇Ｚ为Ｍ型，Ｗ为ＳＭ型．三者Ｚ均略大于Ｗ．草游蛇和渔游蛇Ｎｏ４长臂末端有时可见随体．对游蛇属、链蛇属以及游蛇亚科（Ｃｏｌｕｂｒｉｎａｅ）已知各属种的核型进行了比较和讨论．     

宁南霉素防治烟草花叶病的研究

在我国四川省和云南省进行的总面积９０１．８６ｈｍ２多点防治试验、示范结果表明，农用抗生素宁南霉素对烟草花叶病的防治效果为６９．４％～９５．４％，平均增产效果为２６．１％，均优于目前推广防治烟草花叶病的植病灵、菌毒清和８３增抗剂，并可使烟叶的内在质量明显提高．在温室内施药间隔３～１０ｄ后，人工分别接种烟花叶病毒（ＴＭＶ）、黄瓜花叶病毒（ＣＭＶ）和马铃薯Ｙ病毒（ＰＹＶ），实验表明，宁南霉素对烟花叶病毒（ＴＭＶ）和黄瓜花叶病毒（ＣＭＶ）所引起的烟草花叶病的防治效果高达９２．９％和９０．９％，对马铃薯Ｙ病毒（ＰＹＶ）引起的烟草花叶病的防治效果达５３．８％．     

New analytical formulations for calculation of dispersion parameters of Gaussian model using parallel CFD

New analytical formulations are presented for calculation of most effective parameters in the Gaussian plume dispersion model; the standard deviations of concentration for horizontal and vertical dispersion in neutral atmosphere conditions. Employing parallel Computational Fluid Dynamics (CFD) as a powerful tool, some well-known analytical generations of Pasquill–Gifford–Turner experimental data are modified. To achieve this aim, CFD simulations are carried out for single stack dispersion on flat terrain surface and ground level concentrations are determined in different distances. An inverse procedure in Gaussian plume dispersion model is then applied and standard deviations of horizontal and vertical dispersions are obtained. The values are compared with those of the well-known methods of Doury, Briggs and Hanna in two cases: the experimental data for release of krypton-85 from 100 m high and pollution dispersion from three 28 m high stacks of Besat power plant near Tehran. The comparison indicates that new formulations for plume dispersion are more accurate than other well-known formulations.     

Verification of the plume rise/dispersion model USPR: plume rise for single stack emissions

Despite proliferation of the use of air pollution models for regulatory application, major discrepancies still occur between models and also between models and observations, especially when oversimplistic models are used. The problem of predicting plume rise (and subsequently ground level concentrations) from a single source is evaluated here in terms of an integral plume rise and dispersion model (USPR) which encompasses both bouyant rise and turbulent spreading; thus avoiding the problems of the concatenation of separate plume rise and dispersion models. The wide range of validity of the USPR model is demonstrated is terms of plume rise by comparison with the highly buoyant GCOS and Kincaid plumes as well as with dense effluents. It is also shown to be in agreement with Briggs' two-thirds law when the restrictions applicable to the latter model are imposed.     

Large eddy simulation of plume dispersion behind an aircraft in the take-off phase

The aim of this paper is to provide an investigation, using large eddy simulation, into plume dispersion behind an aircraft in co-flowing take-off conditions. Validation studies of the computational model were presented by Aloysius and Wrobel (Environ Model Softw 24:929–937, 2009) and a study of the flow and dispersion properties of a double-engine aircraft jet was presented by Aloysius et al. (EEC/SEE/2007/001, EUROCONTROL Experimental Centre, ), in which only the engine was modelled. In this paper, the complete geometry of a Boeing 737 is modelled and investigated. The current work represents a contribution towards a better understanding of the source dynamics behind an airplane jet engine during the take-off and landing phases. The information provided from these simulations will be useful for future improvements of existing dispersion models.     

Plume rise and spread in buoyant releases from elevated sources in the lower atmosphere

This study focuses on the influence of emission conditions—velocity and temperature—on the dynamics of a buoyant gas release in the atmosphere. The investigations are performed by means of wind tunnel experiments and numerical simulations. The aim is to evaluate the reliability of a Lagrangian code to simulate the dispersion of a plume produced by pollutant emissions influenced by thermal and inertial phenomena. This numerical code implements the coupling between a Lagrangian stochastic model and an integral plume rise model being able to estimate the centroid trajectory. We verified the accuracy of the plume rise model and we investigated the ability of two Lagrangian models to evaluate the plume spread by means of comparisons between experiments and numerical solutions. A quantitative study of the performances of the models through some suitable statistical indices is presented and critically discussed. This analysis shows that an additional spread has to be introduced in the Lagrangian trajectory equation in order to account the dynamical and thermal effects induced by the source conditions.     

Quantifying the importance of regional and local filters for community trait structure in tropical and temperate zones

The influence of regional and local processes on community structure is a major focus of ecology. Classically, ecologists have used local-regional richness regressions to evaluate the role of local and regional processes in determining community structure, an approach that has numerous flaws. Here, we implemented a novel trait-based approach that treats local and regional influences as a continuum, rather than a dichotomy. Using hylid frogs (Hylidae), we compared trait dispersion among members of local species assemblages to the trait dispersion in the regional assemblage from which they were drawn. Similarly, we compared trait dispersion in the regional assemblages to dispersion in the continental species pool. We estimated the contributions of local and regional filters, and we compared their strength in temperate and tropical zones. We found that regional and local filters explained 80% of the total variation among local assemblages in community body size dispersion. Overall, regional filters reduced trait dispersion, and local filters increased it, a pattern driven by particularly strong antagonistic effects in temperate zones that reduced the realized total variation by more than 40%. In contrast, local and regional filters acted in concert in tropical regions. Patterns within the tropics did not differ from the random expectation based on a null model, but within the temperate zone, local community filtering was stronger than expected by chance. Furthermore, in temperate regions, antagonistic regional and local filtering masked from 76% to 90% of the total variation in trait dispersion. Together, these results suggest that there are fundamental differences in the scale and identity of the processes determining community structure in temperate and tropical regions.     

Oceanic Wastewater Outfall Plume Characteristics Measured Acoustically

A study, called SEFLOE, of the dispersion characteristics of several wastewater outfalls was conducted off of the coast of Southeast Florida (USA). in this study, the feasibility of utilizing high frequency (20kHz and 200kHz) acoustic echoes to characterize the dilution characteristics of the effluent wastewater was examined. It is hypothesized that the background corrected acoustic backscattered intensity may be used to guide chemical/biological sampling, and that one or more plume subfields may be revealed by the scattering strength field. Data from SEAFLOE have indicated that the wastewater plume field is divided into regions of higher concentration spatially separated by regions of lower concentration; we call these regions of higher concentration “boluses”. When the water column is density stratified, subsurface plumes may peel off of the main rising plume and remain at equilibrium on a density gradient.     

Integral models for bubble,droplet, and multiphase plume dynamics in stratification and crossflow

We present the development and validation of a numerical modeling suite for bubble and droplet dynamics of multiphase plumes in the environment. This modeling suite includes real-fluid equations of state, Lagrangian particle tracking, and two different integral plume models: an Eulerian model for a double-plume integral model in quiescent stratification and a Lagrangian integral model for multiphase plumes in stratified crossflows. Here, we report a particle tracking algorithm for dispersed-phase particles within the Lagrangian integral plume model and a comprehensive validation of the Lagrangian plume model for single- and multiphase buoyant jets. The model utilizes literature values for all entrainment and spreading coefficients and has one remaining calibration parameter \( \kappa \), which reduces the buoyant force of dispersed phase particles as they approach the edge of a Lagrangian plume element, eventually separating from the plume as it bends over in a crossflow. We report the calibrated form \( \kappa = [(b - r) / b]^4 \), where b is the plume half-width, and r is the distance of a particle from the plume centerline. We apply the validated modeling suite to simulate two test cases of a subsea oil well blowout in a stratification-dominated crossflow. These tests confirm that errors from overlapping plume elements in the Lagrangian integral model during intrusion formation for a weak crossflow are negligible for predicting intrusion depth and the fate of oil droplets in the plume. The Lagrangian integral model has the added advantages of being able to account for entrainment from an arbitrary crossflow, predict the intrusion of small gas bubbles and oil droplets when appropriate, and track the pathways of individual bubbles and droplets after they separate from the main plume or intrusion layer.     

Chemical Tracking and Marine Environmental Impact of Ocean Disposal of Calcium Carbonate Residue in the North Yellow Sea

The objective of this study is to determine the sedimentation rate and dispersion area of calcium carbonate residue dumped at sea and the impact to marine environment of dumping by a laboratory simulation experiment; chemical tracking in the field with the help of acoustic and optical tracking; and a comparative study of baseline conditions and marine environmental impact after dumping. Turbidity, pH and phosphate are selected as the chemical tracers to be monitored.

Results show that in the dumping area of 15 square miles with water depth of 50 m, if 217 t calcium carbonate residue is dumped (spot dumping) in the presence of a pycnocline with a current velocity of 60 cm/s (close to the maximum) the maximum dispersion distance of the calcium carbonate residue plume front is less than 2100 m; the dispersion area is less than 0.56 km²; and the maximum dispersion time is about 60 min when the turbidity and pH in the whole dispersion area return to background level. Therefore, the ocean disposal of calcium carbonate residue is feasible.     

Numerical analysis on the Brisbane River plume in Moreton Bay due to Queensland floods 2010–2011

During the Queensland floods in the summer of 2010–2011, a flood-driven Brisbane River plume extended into Moreton Bay, Queensland, Australia, and then seaward, travelling in a northward direction. It covered approximately 500 km $^{2}$ . This paper presents a three- dimensional hydrodynamic numerical model investigation into the behaviour of the Brisbane River plume. The model was verified by using satellite observations and field measurement data. The present study concludes that the high river discharge was the primary factor determining the plume size and its seaward extensions. A notable finding was that the plume was a bottom-trapped type rather than a buoyant type. Further, the southerly winds were found to have moderately confined the alongshore extension of the plume, and had caused the plume to mix thoroughly with the ocean water.