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1.
John G. Papageorgiou 《Boundary-Layer Meteorology》1988,45(1-2):9-29
A 3-D sea breeze model has been developed to study the sea breeze and the pollutant dispersion over a coastal area. Topography is also included. Similarity theory is adopted while a turbulent kinetic energy equation is used to study turbulence and to parameterize eddy diffusion. The integration is repeated in diurnal cycles and the results — meteorological and pollutant — are compared with data from the Athens area. 相似文献
2.
利用丽水2012年9月—2014年3月主要空气污染物浓度和气象数据,分析丽水空气污染物构成及其与气象因子的相关性。分析结果表明:丽水空气质量优良率约80%,高频首要污染物依次为PM2.5、O38、PM10、NO2;各污染物浓度分布的时间、季节特征明显:早晚高峰时段污染物浓度普遍偏高,冬季—初春是一年中污染较重季节,尤其春节期间PM和SO2浓度急剧上升。各主要污染物质浓度随气象因子的变化各有特点:CO在气温较高、晴朗微风、高层层结稳定的天气条件下浓度较高;NO2在气温适中、湿度较大且无明显降水时浓度较高;SO2则在气温适中、湿度较小、晴朗微风的天气条件下浓度较高;O3则在高温干燥天气时浓度较高;PM在干燥、气温较低、连续晴朗、微风、高层层结稳定时浓度较高。 相似文献
3.
利用2017年福建漳州和南部海岛气象观测资料,通过统计分析和人工订正判识海陆风日,再结合天气形势和污染物浓度资料分析海陆风日的天气特征及其与污染物浓度的关系。结果表明：漳州海陆风日是海岛站的2.2倍,春夏季是海陆风的高发季节,秋冬季相对较少。冬季海陆风日主导天气形势为变性冷高压、高压后部、锋前暖区等,气象要素场配置为气压梯度小、气温高、风速小、日照时间长、湿度低、云量少,气象条件不利于污染物的稀释、扩散;海陆风影响下除了O3,其他5种污染物浓度均高于系统风日2—3倍,其中颗粒物浓度明显偏高。与冬季不同,春季海陆风不仅对颗粒物浓度升高有利,对O3浓度升高贡献更加明显,主导天气形势、气象要素场配置与冬季类似;海陆风影响下所有污染浓度均高于系统风日1—2倍,且易出现O3超标现象。研究显示,漳州的海陆风全年发生频率虽然不到30%,但其特有的日变化规律和局地环流结构对污染物累积、输送具有重要的影响。 相似文献
4.
Summary A dispersion modeling system consisting of a three-dimensional PBL model NHECM (non-hydrostaticE- closure model) and SLPTDM (seven-level puff transport and diffusion model) is developed to simulate the transport and dispersion of pollutant over coastal complex terrain. As an application of the system, the transport and dispersion of SO2 released from an elevated point source are simulated during typical sea-land breeze circulation in the Hongkong-Shenzhen area of China. The NHECM provides time-varying, three-dimensional distributions of wind and turbulence fields to the SLPTDM. The NHECM predictions compare well with observational data. Reflection of both the ground and the mixing layer top and penetration of the mixing layer top are improved in the SLPTDM. Results obtained from the system indicate that temporal variation and nonuniformity of airflow and turbulence obviously affect the concentration distributions, especially during the sea-land breeze transition period. A diurnal cycle of the GLC (ground-level concentration) is discussed. The results are compared with those estimated using a Gaussian model. The study's results illustrate the complexity of the dispersion patterns due to diurnal effects and mesoscale circulations, and demonstrate the potential of the mesoscale atmospheric dispersion modeling system for studies of air quality in complex terrain.With 8 Figures 相似文献
5.
Li Mengmeng Wang Tijian Xie Min Zhuang Bingliang Li Shu Han Yong Cheng Nianliang 《Theoretical and Applied Climatology》2017,128(3-4):999-1013
Through regulating the land–atmosphere energy balance, urbanization plays an important role in modifying local circulations and cross-border transport of air pollutants. The Beijing–Tianjin–Hebei (BTH) metropolitan area in northern China is frequently influenced by complex atmospheric thermal circulations due to its special topography and geographic position. In this study, the Weather Research and Forecasting (WRF) model combined with remote sensing is used to explore the urbanization impacts on local circulations in the BTH region. The urban heat island (UHI) effect generated around Beijing and Tianjin shows complex interactions with local thermal circulations. Due to the combined effects of UHI and topography, the UHI circulation around Beijing and valley breeze at the southern slopes of Yan Mountain are coupled together to reinforce each other. At the coastal cities, the increased land/sea temperature gradient considerably accelerates the sea breeze along Bohai Bay and moves the sea breeze front further inland to reach as far as Beijing. This study may lay a foundation for the better understanding of air pollutant dispersion on complex terrain.
相似文献6.
A Two-Dimensional Numerical Study of the Impact of a City on Atmospheric Circulation and Pollutant Dispersion in a Coastal Environment 总被引：3，自引：0，他引：3
Alberto Martilli 《Boundary-Layer Meteorology》2003,108(1):91-119
The urban impact on the sea breeze is studied by means of a mesoscale model with a detailed urban parameterisation. Four simulations are carried out on an idealised two-dimensional flat domain. In the base case, half of the domain is characterised by seaand the other half by rural land. In the urban case, an urban area 10 km wide is added near the shoreline. Simulations are performed for a moist rural soil (weak sea breeze) and for a dry rural soil (strong sea breeze). Results are analysed in order to evaluate the impact of the city on the wind, temperature and turbulent kinetic energy fields. The dispersion of a passive tracer emitted near the coastline is, also, used in the comparison. Results show that the city accelerates the sea-breeze formation in the morning (combinations of urban circulation and sea breeze), but it slows thesea-breeze front penetration. Moreover, the presence of the city enhances the recirculation processes and strongly modifies the pollutant dispersion. These effects are enhanced for a moist rural soil. 相似文献
7.
中国地区山谷风研究进展 总被引：1，自引：0，他引：1
随着城市化的发展,越来越多的城市建立在山区附近或山谷之中。受地理环境和气象条件等因素影响,各地山谷风特征各不相同。山谷风对局地风场、气候特征有着重要作用,与逆温和污染物浓度变化也具有良好相关。本文从山谷风研究的主要手段—观测、理论和数值模拟出发,重点回顾了国内山谷风研究成果,并讨论了与其他中尺度环流(海陆风、湖陆风、城市热岛、植被风、冰川风环流)的相互作用,以及包括山谷风在内的山地环流对大气污染的影响。最后对国内研究进展进行总结,并提出了一些还需深入研究和探讨的问题。 相似文献
8.
Meteorological measurements were carried out at North Chennai semi rural area during pre-monsoon period as a part of an air quality study program. Analysis of the data showed the effects of coastal terrain namely the land-sea breeze circulation, temperature cooling during the sea breeze, difference in onset times at these sites etc. Sea breeze onset was observed with a sharp turning of the wind from westerly to south easterly associated with rise in wind speed. Advection speed of the front was about 2.0 m s− 1. A simple mesoscale meteorological model (MAM-I) developed at Kalpakkam for coastal atmospheric dispersion estimation was used to simulate the observed characteristics. All the major features observed could be simulated by the model while significant difference was noticed in sea breeze frontal movement. MAM results were also inter-compared with MM5. There were no significant differences in the estimate of mean parameters by both the models. It is concluded that the simple model, which takes less run time in a desktop PC, is adequate enough for practical application of providing wind field for plume dispersion models at coastal sites. 相似文献
9.
The structure and evolution of the sea breeze in the north-west part of the Mediterranean (Catalonia, north-east Spain) is
studied both experimentally and, predominantly, using numerical models to increase understanding of sea-breeze structure and
three-dimensional (3D) pollution distributions in coastal environments. Sea-breeze components are modelled and analyzed using
the fifth-generation Pennsylvania State University–National Centre for Atmospheric Research Mesoscale Model (MM5). The results
show that the growth and structure of the sea-breeze circulation is modulated by the synoptic flow and especially by the complex
topography of the area. 3D pollution transport in a sea breeze is modelled by coupling the MM5 to the Community Multiscale
Air Quality (CMAQ) model, with results indicating that topography and synoptic flow are the main factors modulating horizontal
and vertical pollutant transport in sea-breeze episodes. In this way, horizontal dispersion is limited by the complex topography
of the area, whilst the sea-breeze flow is intensified by anabatic upslope winds that contribute to vertical pollutant transport.
The numerical model results also indicate that the sea-breeze circulation with a weak return flow at upper levels grows due
to a synoptic onshore wind component. However, such a sea-breeze circulation is capable of transporting pollutants towards
the coast. 相似文献
10.
Raymond W. Arritt 《Boundary-Layer Meteorology》1987,40(1-2):101-125
A two-dimensional prognostic numerical model has been used to study a lake breeze event reported by Keen and Lyons (1978). Model predictions showed fair to good agreement with the observations. For the mature lake breeze, the model predicted inflow at the coast within about 1.5 m s–1 of the observed value, lake breeze depth within 50–90 m of the observed, and inland penetration within about 6 km of the observed. The top of the thermal internal boundary layer (TIBL) was associated with a minimum in the predicted turbulent kinetic energy profile. This may be of consequence for attempts to evaluate pollutant dispersion using numerical models.Predicted lake breeze characteristics showed little sensitivity to temperature of the water surface, except when the water surface temperature was increased to a value exceeding the inland maximum temperature. The most sensitive lake breeze characteristic was the TIBL, which grew more slowly with inland distance and persisted for a greater distance inland as the lake surface became colder. 相似文献
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12.
复杂地形城市冬季大气污染的数值模拟研究 总被引：10，自引：21，他引：10
采用中尺度大气动力模式与大气扩散模式相结合的方法，针对复杂地形条件下兰州市冬季无明显冷空气入侵天气过程时段（1994年12月2－3日）的大气污染状况，进行污染物（二氧化硫和烟尘）浓度分布的数值模拟研究，分析了模拟的风场的气温层结随时间的变化以及污染物浓度的分布及其变化，进一步分析了模拟的风场和气温层结与污染物浓度分布的关系。结果表明，该模式系统对兰州市大气边界层结构及污染物浓度的分布有较好的模拟能力，并证明了该模式系统可适用于兰州市大气质量预测预报研究。 相似文献
13.
R. Salerno 《Theoretical and Applied Climatology》1992,45(1):19-35
Summary Dispersion and transport over complex terrain have been recognized as an important research field. In July 1988, for studying atmospheric dispersion in a mountain area, a tracer experiment has been performed in south alpine valleys near a mountain (Campo dei Fiori, 1226 m.a.s.l.). In this area air masses circulation in wind breeze conditions is frequent. This paper analyses the meteorological situation and the tracer dispersion during those experiments. First a reconstruction of the three-dimensional wind fields overCampo dei Fiori area, taking into account the effects of orography, surface thermal gradients, atmospheric stability and energy of air masses, has been performed. Then the tracer concentrations have been evaluated by means of suitable models and the results have been discussed.With 11 Figures 相似文献
14.
利用2013—2014年邯郸市环境监测站环保资料、邯郸气象站地面观测资料及邢台站探空资料,分析了邯郸大气环境特征及影响污染物扩散的气象条件,结果表明：空气重污染主要发生在秋冬季和初春季节;2014年影响污染物扩散的气象条件与2013年的大体相当,但2014年邯郸重污染日数减少,达标日数增加,污染物浓度较2013年的下降,重污染天气持续时间较2013年的明显减少,表明邯郸市实施的一系列减排措施效果明显。 相似文献
15.
A new scaling approach, based on the convective velocity obtained from the sun-exposed eastern slopes and thus suited for
steep and narrow Alpine valleys, is investigated with respect to pollutant dispersion. The capability of the new method is
demonstrated with the operational emergency response system of MeteoSwiss, which consists of the COSMO (COnsortium for Small-scale
MOdelling) numerical weather prediction model coupled with a Lagrangian particle dispersion model (LPDM). The new scaling
approach is introduced to the interface between COSMO and LPDM, and is compared to results of a classical similarity theory
approach and to the operational coupling type, which uses the turbulent kinetic energy (TKE) from the COSMO model directly.
For the validation of the modelling system, the TRANSALP-89 tracer experiment is used, which was conducted in highly complex
terrain in southern Switzerland. The ability of the COSMO model to simulate the valley wind system is assessed with several
meteorological surface stations, and the dispersion simulation is evaluated with the measurements from 25 surface samplers.
The sensitivity of the modelling system towards the soil moisture, horizontal grid resolution, and boundary-layer height determination
is investigated, and it is shown that, if the flow field is correctly reproduced, the new scaling approach improves the tracer
concentration simulation when compared to classical coupling methods. 相似文献
16.
NUMERICAL ANALYSIS OF THREE-DIMENSIONAL STRUCTURE OF THE SEA BREEZE OVER SOUTHWESTERN BOHAI GULF 总被引：1，自引：0，他引：1 
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下载免费PDF全文 Wu Zengmao 《Acta Meteorologica Sinica》1988,2(2):175-186
In this paper,a simulation study is made on the sea breeze process over southwestern Bohai Gulf byuse of the Pielke mesoscale meteorological model.The simulated results show that when a south wind of 8m/s blows over the top of the model,a strong wind zone of 15—25 km wide with a maximum speed more than14 m/s,which is close and nearly parallel to the south shore,will appear at 160 m above the sea surface.When a strong sea breeze penetrates inland,there often appears a thermal internal boundary layer(TIBL)near shore.The inversion above the TIBL can damp the vertical dispersion of atmospheric pollution.Besides,it is also found that,for a three-dimensional sea/land breeze circulation,if the divergence centre inthe return flow departs vertically far from the correspondent convergence centre in the sea breeze,a centre ofstrong descending movement will be formed at the middle and upper levels of the return flow.The resultsin this paper is also applicable to the Laizhou Bay. 相似文献
17.
In this paper a 3-D mesoscale PBL dynamic prognostic model for a coastal region with complex terrain was developed to simulate the 3-D flow field under a local sea-land breeze circulation. The output from the PBL model was used as an input to an Eulerian numerical model which can be used to simulate finely the temporal and spatial distributions of an air pollutant (SO2) during a sea-land breeze developing in a coastal region. With respect to its use as a diagnostic model, only a few data would be required to simulate the background winds controlled by a larger scale synoptic system, and then provide initial winds for the PBL model.Having linked the three models and defined the coefficients of turbulent diffusion in a simple form, an integrated 3-D numerical air quality model suitable for the coastal environment was designed. The period of May 29, 1986 was selected for simulating and analysing the distribution of air pollutants over the coastal area of Bohai-sea in Northern China. The results indicated that the calculated concentrations corresponded with the observed ones on the whole. Thus this linked model has been shown to be feasible and useful in practice. 相似文献
18.
A model was developed for pollutant dispersion from a point source simulating the Hadera (Israel) power plant stack. The model is based on the NCAR mesoscale meteorological MM4 model that provides the wind fields and coefficients of turbulent diffusion. The model was implemented using an implicit numerical scheme with changing directions. A comparison between the model calculations and an analytical solution for the advection-diffusion equation shows good agreement. Relatively low numerical diffusion of the adopted advection scheme was noted. Results for the hilly region of central Israel are presented for a summer case. 相似文献
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利用常规气象观测资料、多普勒气象雷达资料、浙江省自动站加密资料、NCEP/FNL再分析资料,结合高分辨率中尺度数值模式WRF对杭州湾地区2016年7月28日一次海风锋触发雷暴天气的发生、发展演变特征进行数值模拟。结果表明:1)海风锋是此次强雷暴天气过程的主要触发系统。2)中尺度模式WRF较好地模拟出此次雷暴过程的降水和低层风场、温度场分布以及海风锋水平垂直结构。3)海风锋对局地比湿及涡度特征的加强有明显的促进作用,为雷暴的发生发展提供有利的水汽和动力条件。4)分析对流参数演变曲线的突变位置,对雷暴发生的时间有一定的指示和预报意义,杭州湾南侧单纯的海风锋也可以触发雷暴的发生发展。 相似文献