dispersion model Articles
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Meteorological data for dispersion modelling: a brief report on the COST 710 programme on pre-processing and harmonisation
Dispersion models need reliable meteorological data to run properly. Some of the meteorological data required by dispersion models are not routinely measured and have to be inferred from other measurements. The purpose of this cooperative study under the COST 710 Action is to improve and harmonise the methods of pre-processing the necessary meteorological input data. This should ensure that ...
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Atmospheric dispersion models for regulatory purposes in the Federal Republic of Germany. Part I: Regulatory modelling
The legal framework for the application of atmospheric dispersion models for air pollution control in Germany is outlined. Atmospheric dispersion models in regulatory procedures are currently essentially based on the Gaussian approach. However, more advanced modelling is already available.Keywords: air pollution control, atmospheric dispersion models, Gaussian model, Germany, regulatory ...
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Regulatory dispersion modelling in Finland
We present a review of regulatory atmospheric dispersion models and their application to environmental impact assessment (EIA) in Finland. The following regulatory models are available: the urban dispersion modeling system, models for dispersion of vehicular pollution, the air pollution information system, and the dispersion model for odorous compounds. All of these models are connected to a ...
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Dry deposition modelling in a Lagrangian dispersion model
Revisions to the dry deposition scheme in the Lagrangian dispersion model, NAME, are described. Improvements are made for situations where material is not well mixed within the boundary layer and for sedimenting heavy particles. The revised scheme overcomes problems of computational noise, common in Lagrangian dispersion models, with a manageable or no increase to the computational cost. The ...
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A neural net-air dispersion model validation study using the Indianapolis urban data set
It is presented an integrated model composed by a dispersion model and a Neural Net (NN). The NN uses the concentrations predicted by the an analytical dispersion model as input variables of the net. This methodology was validated using Indianapolis urban data set where releases from an elevated emission source were considered. An improvement of performances is shown when the neural network is ...
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The harmonisation of gas dispersion modelling for industrial applications: a few thoughts for the future
The Gas Dispersion Modelling Harmonisation Initiative has been successful in highlighting significant differences between models for quantifying the dispersion of gaseous emissions. Possible areas for developing the initiative further are detailed in this paper. The key issues raised are: a) The need for a definitive set of full-scale experiments to quantify dispersion from stacks with heights in ...
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Gas dispersion modelling harmonisation: an industrial viewpoint
The harmonisation of gas dispersion modelling across Europe requires not only harmonisation of the physics incorporated into different mathematical models but also harmonisation of the way that practitioners actually use these models. This paper highlights the need to define minimum acceptable standards for gas dispersion modelling, especially in the specification of source conditions and ...
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`Understanding and Adapting to New Dispersion Models,` published in the Oregon Insider, December 2001
The U.S. Environmental Protection Agency (EPA) has proposed revisions to its air dispersion modeling guidance1 ("Guideline on Air Quality Models", or simply "Guideline"), found in 40 CFR 51 Appendix W.2 These revisions, once finalized, will create significant changes in the way that air quality analyses are performed in the US, and perhaps the most significant changes since (he Guideline was ...
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CEC model evaluation group: an account of the activities of the Heavy Gas Dispersion Expert Group
The heavy gas dispersion expert group is one of the three groups so far set up by the CEC Model Evaluation Group. This paper describes the activities of the group. The main results of these activities are: (i) a tested heavy gas dispersion model evaluation protocol, (ii) a list and classification of available models and (iii) a list and classification of relevant datasets.Keywords: heavy gas ...
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Efficient calculation of urban scale air pollutant dispersion and transformation using the OFIS model within the framework of CityDelta
CityDelta is a model intercomparison exercise that assesses the performance of the participating models and compares them against observational data, allowing at the same time their validation and further development. In this framework, OFIS, an Eulerian photochemical dispersion model, was applied in several European cities, for both gaseous pollutants and particulate matter. The basic concept of ...
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Validation of the improved AEROPOL model against the Copenhagen data set
The improved Gaussian dispersion model AEROPOL (University of Tartu, Estonia) is validated against the Copenhagen air pollution dispersion dataset belonging to the Model Validation Kit of the Initiative on "Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes". Model updates include the application of: surface heat flux instead of indirect indicators of surface layer ...
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Understanding and Adapting to New Dispersion Models
The U.S. Environmental Protection Agency (EPA) has proposed revisions to its air dispersion modeling guidance1 (“Guideline on Air Quality Models”, or simply “Guideline”), found in 40 CFR 51 Appendix W.2 These revisions, once finalized, will create significant changes in the way that air quality analyses are performed in the US, and perhaps the most significant changes since the Guideline was ...
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ADMS–Urban: developments in modelling dispersion from the city scale to the local scale
Many countries perform national air quality assessments using grid–based numerical air dispersion models, generally referred to as 'regional' models. Advantages of these models include the ability to use temporally and spatially varying meteorology and model chemical reactions over large temporal and spatial scales. These models usually perform reasonably well against rural and urban background ...
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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 meteorological database for next-generation dispersion models, and a Lagrangian particle model based on kinematic simulation theory
The database system supports small to regional scale air pollution analysis and dispersion modelling. It provides a three-dimensional and time dependent description of relevant meteorological scalar and vector quantities, and also trajectories and meteorological input data for commonly used dispersion models for local and regional applications. The data are visualized on a standard PC with ...
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Development of numerical model for dispersion over complicated terrain in the convective boundary layer
Complicated terrain and atmospheric stability are important factors in the predicting the dispersion of air pollutants. The aim of our study is to develop practical dispersion model for unstable conditions for regulatory use. The numerical model we adopted was a combination of the potential flow model and Lagrangian stochastic dispersion model. In this model, time-mean flow field is solved by the ...
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Dispersion modelling: a tool for local air quality management
A local air quality management system, and the use of dispersion modelling as a tool for the system, are described. The Turkish town of Gehze is used as a model.Keywords: air pollution, air quality management, dispersion modelling, ...
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Consolidating tools for model evaluation
An overview is provided of some central tools and data sets that are currently available for evaluation of atmospheric dispersion models. The paper serves as a guide to the Model Validation Kit, which was introduced already in 1993, but has undergone a recent revision. The Model Validation Kit is a package of field data sets and software for model evaluation plus various supplementary materials. ...
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Comparison of the Polish regulatory dispersion model with AERMOD
Implementation of the 96/62/EC air quality directive in Poland imposes new requirements that cannot be met by the present Polish regulatory climatological dispersion model that is mandatory in emission permit procedures. For use in the air quality management system, newer models have been recommended. This inevitably brings questions regarding consistency between models used for both the ...
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Effective use of radiation monitoring data and dispersion calculations in an emergency
An essential prerequisite for the proper management of a radiation emergency is that measurement data and calculation prognoses are available and that they are produced in an efficient manner. This paper reviews some of the factors contributing to the practice of performing radiation measurements and atmospheric-dispersion-model calculations effectively and discusses the issues related to the ...
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