air pollution model Articles
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An air quality modelling system for a medium-sized town: a case study in Estonia
The air pollution modelling system used in Tartu (population 101,000) is aimed at examining the pollution levels in different meteorological conditions, and determining optimal traffic schemes and strategic development plans for the city. The system consists of: (i) a Gaussian plume model AEROPOL, and (ii) a database on sources of NOx2Keywords: AEROPOL model, air pollution modelling, air ...
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Dependence of street canyon concentrations on above-roof wind speed - implications for numerical modelling
For microscale numerical modelling of street canyon air pollution, the traffic-related component of the total ambient pollutant concentration is often assumed to be inversely dependent on the wind-speed at rooftops for idealised conditions of neutral stratification, no solar radiation, and no traffic-induced turbulence. Detailed data analyses of two comprehensive datasets from Gottinger Strase ...
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Dispersion modelling near tunnel exits: simulation and measurements
Measurements of car exhaust gases were made in May/June 1995 in the vicinity of the Bielefeld tunnel. CO and NOx from car exhausts were measured to allow comparison with a model simulation. Ozone was also measured. These measurements were made using commercial continuous analysers. A valve control system was used to investigate the dispersion of the trace gases. This allowed measurements at ...
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Evaluation of AirGIS: a GIS–based air pollution and human exposure modelling system
This study describes in brief the latest extensions of the Danish Geographic Information System (GIS)–based air pollution and human exposure modelling system (AirGIS), which has been developed in Denmark since 2001 and gives results of an evaluation with measured air pollution data. The system shows, in general, a good performance for both long–term averages (annual and monthly averages), ...
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A dataset for the validation of flow and dispersion models at an urban intersection
Dispersion modelling concerning air pollution caused by road traffic is reduced to a two-dimensional problem within street canyons. However, significant pollution loads are also to be expected at intersections. In this case, three-dimensional flow and dispersion structures have to be considered. For the validation of models claimed to be applicable to intersections, measurements of meteorological ...
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Field measurements within a quarter of a city including a street canyon to produce a validation data set
Air pollutants and meteorological parameters were measured continuously by in situ instruments, path-averaging techniques (up to three DOAS systems), and SODAR inside a street canyon and in the surrounding area of 1 km x 1 km (Gottinger Strasse in Hanover, Germany) from 2001 until 2003 which are available in the data bank ValiData for validation of microscale models. During three IOPs tracer ...
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Evaluation of dispersion models for an urban environment: an example from Stockholm, Sweden
An air quality management system has been in operational use in the city of Stockholm, Sweden, for several years. In the system there are, in addition to databases for measurements of air pollution and meteorological parameters and emission data, several dispersion models. The models include a Gaussian and a Eulerian (grid) type of dispersion model. An evaluation of the Gaussian and the grid ...
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Design methodology for background air pollution monitoring site selection in an urban area
We present an air monitoring site selection procedure to determine the minimum number and location of monitoring stations to identify the occurrence of background concentrations greater than a reference value in an urban area. The objective technique reported here is based on the analysis of concentrations estimated using an urban dispersion model for at least one year of hourly information. As ...
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Local mass transfer coefficients over idealised two–dimensional urban street canyons
In view of the large number of urban inhabitants, ventilation and pollutant transport in urban areas are major research problems for several decades. This paper focuses on the studies of the correlation between the ventilation and pollutant removal over idealised two–dimensional urban street canyons using wind tunnel experiments in the Department of Mechanical Engineering, The University of Hong ...
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Comparison of model predictions and measurements near a major road in an urban area
We have compared measured concentration data with predictions from a dispersion modelling system. The measurement campaign was conducted near a major road in the Helsinki Metropolitan area during two months of 1994. The concentrations of five gaseous pollutants (NO, NO2, O3, CO and SO2) were measured at three heights, together with the simultaneous measurement of traffic densities and the ...
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A comprehensive experimental databank for the verification of urban car emission dispersion models
A summary presentation is made of representative samples from a comprehensive experimental databank on car exhaust dispersion in urban street canyons. Physical modelling, under neutral stratification conditions, was used to provide visualisation, pollutant concentration and velocimetry measurements above and inside test canyons amidst surrounding urban roughness. The study extended to two ...
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Parametric study of the dispersion aspects in a street-canyon area
Most modern cities practically consist of street canyons, making monitoring of the level of their pollution an important issue. In this study, a Computational Fluid Dynamics (CFD) simulation of pollutant dispersion was performed for a real, complex-geometry street canyon for various wind directions and speeds. Typical street-canyon effects – like the formation of a longitudinal vortex for wind ...
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Statistical analysis of urban air-pollution data in the Athens basin area, Greece
Air pollutant concentrations recorded in the Athens basin area by a network of stations are analysed and examined to estimate the typical behaviour of the air pollutants, especially with regard to daily, weekly and annual periodicities and meteorological dependencies. Also, an attempt is made to predict daily and monthly concentrations by utilising a statistically based model, that is, a multiple ...
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Analysis of local concentration gradients in complex built environments: implications for Air Quality Management Areas
This paper reviews the existing guidance on placement of permanent air quality monitoring stations within urban areas and suggests the principles for a new, performance-based guidance. An integrated air quality model has been developed and validated for the designated Air Quality Management Area (AQMA) located in Glasgow City Centre to analyse the importance of local concentration gradients on ...
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Pollutant dispersion over two–dimensional idealised urban roughness: a large–eddy simulation approach
A series of two–dimensional (2D) street canyon models with a wide range of building–height–to–street–width (aspect) ratios are employed in this study to elucidate the pollutant transport over idealised urban areas. The large–eddy simulation (LES) is used to resolve the turbulent flows and pollutant transport in the urban boundary layer (UBL) over the street canyons. The results show that the ...
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Application of atmospheric dispersion models to evaluate population exposure to NO2 concentration in Buenos Aires
Chronic or repeated exposure to low concentrations of NO2 may increase the incidence of respiratory infections especially in the most sensitive persons. Air pollution monitoring data obtained in Buenos Aires City reveal that sometimes NO2 Air Quality Guidelines (AQGs) recommended by the World Health Organization (WHO) is exceeded. We estimate hourly background concentrations (Ch) of NOx ...
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Modelling of air pollution in the area of Algiers City, Algeria
Algiers is the political and economic capital of Algeria. The city drains a large part of the activities of the country with intense road traffic. This road traffic is the main source of air pollution, followed by industry and waste combustion. An application of the new road traffic emission model, called EMISENS, is performed to build road traffic emission inventories for the Algiers region. ...
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A methodology for seasonal photochemical model simulation assessment
This paper presents a methodology to evaluate the model-skill assessment in simulating seasonal periods. In the proposed approach, the model evaluation is performed by using statistical and graphical methods. Such indexes and graphics are computed and processed for a limited number of representative domain stations, selected by a procedure based on the Cluster Analysis. Cluster Analysis, ...
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Monitoring of air pollution in Indian metropolitan cities: modelling and quality indexing
Air quality in cities is the result of a complex interaction between natural and anthropogenic environmental conditions. Delhi, as well as many other cities in India, is facing problems concerning air pollution. The increase in industrialisation and the vehicle fleet, poor control on emissions and little use of catalytic converters, produce a great amount of particulate and toxic gases. Data on ...
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The performance evaluation of WinOSPM model for urban street canyons of Nantes in France
Air quality modelling is primarily the quantative approach. It is more difficult as it demands input data accuracy, uncertainties and the efficient methodologies to judge the extent of models accuracy. As a result, model validation has to be regarded as an integral part of the modelling process. Furthermore, models are often validated on a limited number of testcases therefore, appropriate ...
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