atmospheric dispersion model Articles

  • On the dispersion models and atmospheric dispersion

    As an air pollutant is transported, the pollutant disperses into the surrounding air so that it arrives at a lower concentration than it was on leaving the source. Strict environmental regulations worldwide resulted in a growing concern about the validity of air quality dispersion models. The present work is a try to evaluate the applicability of some dispersion models on the emission from an ...


    By Inderscience Publishers

  • Evaluation of statistical models in atmospheric dispersion modelling

    When a gas is released into the atmosphere, there are inevitably random fluctuations in its concentration due to turbulence. Great recent improvements in instrumentation have shown how large these are. This has been acknowledged by CEC (the Commission of the European Communities), for example in that part of its Environment and Climate Programme (Framework IV) dealing with accidents. Likewise, ...


    By Inderscience Publishers

  • Evaluation of new generation atmospheric dispersion models

    The paper considers the regulatory view of evaluating dispersion models. There is no proscription for regulatory studies in the UK, so differences between dispersion calculations from different models and versions of models are then as important as their absolute veracity. An example shows variations in calculated concentration due to variations between two different versions of a model and two ...


    By Inderscience Publishers

  • A review of evaluation procedures for atmospheric dispersion models

    Evaluation of atmospheric dispersion models is vital to justify their use within the air quality component of environmental assessments. The Model Validation Kit, compiled and distributed by Helge Olesen of NERI, is often used for such evaluations. Whilst the Model Validation Kit has a wide range of functionality, its users often limit their evaluation to a few simplistic calculations. ...


    By Inderscience Publishers

  • Uncertainty adjustments to deterministic atmospheric dispersion models

    Atmospheric Dispersion Models (ADMs) are routinely used in environmental impact assessment, risk analysis, and source apportionment studies. There are a variety of such computational ADMs, but these models usually only provide deterministic predictions or estimation of uncertainty. By introducing error components in ADMs, we formulate statistical modelling to obtain more precise prediction. These ...


    By Inderscience Publishers

  • Modelling of atmospheric pollutant dispersion in coastal areas

    Some characteristics of air pollution in Tarragona (Spain) were investigated. Tarragona has an important petrochemical industry in a coastal region with a complex terrain. The study was made numerically in sea breeze conditions with a three-dimensional mesoscale meteorological model. The temporal and spatial variations of the wind fields have been used in the Lagrangian equation for a ...


    By Inderscience Publishers

  • Validation of atmospheric dispersion models using ETEX data

    Two models frequently used to simulate the dispersion of pollutants in the atmosphere have been compared. This is necessary because only a well-tested and well-calibrated simulation model can be a good representation of the reality of the dispersion of pollutants. The models evaluated (HYSPLIT_4 with its four variants and MEDIA) were run using as input parameters the same meteorological dataset ...


    By Inderscience Publishers

  • A model for simulating atmospheric dispersion in low-wind conditions

    A practical model for low-wind conditions was derived by integration of an instantaneous three-dimensional Gaussian puff equation, in which wind speed was assumed to be zero and standard deviations of a smoke (σy and σz) were expressed as a linear function of the dispersion time. When the plume spreads σy and σz were ...


    By Inderscience Publishers

  • Modelling of atmospheric flow and dispersion in the wake of a cylindrical obstacle

    The computational fluid dynamics code ADREA–HF is used to simulate atmospheric dispersion field experiments around an isolated cylindrical obstacle and two upwind sources of ammonia and propane, with the ammonia source located at different lateral positions. Model calculated concentrations and concentration fluctuations are compared with the experimental results, to investigate the effect of the ...


    By Inderscience Publishers

  • Atmospheric dispersion modelling for regulatory purposes in the United Kingdom

    Short-range atmospheric dispersion models are used to assess the environmental impact of airborne pollutants from industrial plants. The results are of interest to a range of specialist and non-specialist groups, including regulators, operators, environmental organisations, and local residents. In order that these groups can be well-informed, it is important to develop clear and consistent ...


    By Inderscience Publishers

  • Regulatory atmospheric short and medium range dispersion models in Italy

    Since the (partial) acceptance in Italy of the EU Directive 85/337/EEC concerning environmental impact assessment procedures, there has been a rapid growth in the use of atmospheric dispersion simulation tools, which are also being used in air-quality management plans. This paper describes the state of the art in the development and application in Italy of the short and medium range ...


    By Inderscience Publishers

  • Canarina DISPER Software · atmospheric dispersion model · algorithms 6

      Canarina DISPER Software · atmospheric dispersion model   9.1 Point source emissions   The model uses a steady-state Gaussian plume equation to model emissions from point sources, such as stacks.   9.1.1 ...

  • Turbulence closure in atmospheric circulation model and its influence on the dispersion

    In this work the comparisons between measured and numerically simulated tracer experiments are presented for two different datasets. Different versions of the model system RMS, including the Regional Atmospheric Modelling System (RAMS) and the dispersion model SPRAY, accounting for alternative turbulence closures are used. These last are the Mellor and Yamada model level 2.5 and two versions of ...


    By Inderscience Publishers

  • Comparison between analytical models to simulate pollutant dispersion in the atmosphere

    We present a numerical and statistical comparison between ADMM and GILTT approaches to simulate pollutant dispersion in the Planetary Boundary Layer (PBL). The numerical and statistical comparison of the ADMM and GILTT results confirms the equivalence of these methods. However, the ADMM approach is more efficient under computational point of view regarding the issue of computational time and, ...


    By Inderscience Publishers

  • Statistical evaluation of centreline concentration estimates by atmospheric dispersion models

    Within the American Society for Testing and Materials (ASTM), a standard practice (Z6849Z1) is being developed to provide an objective statistical procedure for comparing air quality simulation modelling results with tracer field data. The practice is limited to steady state, local-scale transport from isolated point sources in simple terrain. Evaluation data having similar external conditions ...


    By Inderscience Publishers

  • Canarina DISPER software · atmospheric dispersion modeling · commands 9

    XZ-Plane (perpendicular to land surface):   In such a case, the program window is a XZ-plane (perpendicular to the land surface). A pollutant point source (stack) is represented by a small square. In the Status bar at the bottom, we have X,Y and Z coordinate values in meters and data on our environmental system. Point the mouse where ...

  • Dispersion models in Greece

    Various dispersion models for passive pollutants, as well as heavy gases, are used in Greece for environmental impact applications. The models are based on degree of complexity, and range from simple Gaussian or box models to CFD approaches. The models are used for environmental impact studies in power installations, chemical facilities and for nuclear emergencies. Reflecting the author's ...


    By Inderscience Publishers

  • Statistical procedure for the inter-comparison of atmospheric dispersion models and model calibration with measurements

    Special analytical methodology for model-model and model-measurement comparison is presented. It can be used with the data provided by airborne transport models. Basic statistical procedures have been elaborated for model calibration and for analysis of the quality and representativeness of the datasets. Special adaptation of well-known methods and elaboration of new ones have been carried out to ...


    By Inderscience Publishers

  • Comparative sensitivity study for operational short range atmospheric dispersion models

    Eight atmospheric dispersion models are compared in a sensitivity study in which the responses towards variations in model input parameters are evaluated. For a single source the values of eight practical model input parameters are varied. The model response is evaluated by examining the maximum value of the 98th percentile of the hourly averaged concentration values. The results are represented ...


    By Inderscience Publishers

  • A method of evaluating the topographical effect on atmospheric dispersion using a numerical model

    A method of evaluating topographical effects on exhaust gas dispersion using a numerical model is proposed. The numerical model consists of a turbulence closure model and a Lagrangian particle dispersion model. The topographical effect was evaluated in terms of the ratios of maximum concentration and the distance of the point of maximum concentration from the source on the topography to the ...


    By Inderscience Publishers

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