atmospheric boundary layer Articles
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Simple model of the Urban Atmospheric Boundary Layer (UABL)
The horizontally homogeneous atmospheric boundary layer over a rough surface with a large roughness length z0 has been investigated to model the simplest cases of the Urban Atmospheric Boundary Layer (UABL) over a flat plain. It has been demonstrated that the nondimensional profiles of the horizontal Reynolds stresses of eddy viscosity and of velocity defect components are universal and ...
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Evaluation of the influence of micrometeorological data on concentration estimates
A dispersion model for continuous releases of pollutants in the atmospheric boundary layer is applied to study the influence on modelled concentrations of different estimates of the key micrometeorological variables that represent the dispersion processes. The modelling approach is based on the advection-diffusion equation and includes profiles of wind and eddy diffusivity for the entire ...
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Local scale PC-oriented Eulerian pollutant transport model PolTran-1-2
A one-dimensional non-stationary numerical Atmospheric Boundary Layer (ABL) model is combined with an Eulerian advective scheme, called TRAP. The input information includes meteorological measurements at the surface and high level information from weather forecast centres. The Boundary Layer model includes a comprehensive set of equations governing the meteorological processes (momentum, ...
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Verification of SBL models by mobile SODAR measurements
Models of atmospheric pollutant transport need information about the structure of the atmospheric boundary layer (ABL). The most important characteristics for such applications are the parameterisation of the stable boundary layer (SBL) and the mixing layer height (MLH). Recently, many different schemes have been employed to calculate the SBL height, but there are many problems with applying ...
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On the consideration of mesoscale transports in climate modelling
The dynamical effect of land surface heterogeneity on heat fluxes in the atmospheric boundary layer (ABL) is investigated using numerical simulations with a nonhydrostatic model over a wide range of grid resolutions. It is commonly assumed that mesoscale or dynamical fluxes associated with mesoscale and convective circulations simulated by a high-resolution model (subgrid (SG) model) on the ...
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Meteorological simulations with use of satellite data for assessing urban heat island under summertime anticyclonic conditions
The aim of this study was to investigate the formation, evolution and evaluation of topography effects on the urban heat island over the city of Zagreb. For this purpose, the non-hydrostatic mesoscale meteorological model MEMO was used and high-resolution simulations were carried out for two summertime anticyclonic periods. Satellite data were used to improve the model's performance. The ...
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On the new parameterisation of the eddy diffusivity for radioactive pollutant dispersion
In the present work, starting from the evolution equation for the turbulent energy density spectrum, we develop a new model for the growth of the turbulence in convective boundary layer. We apply dimensional analysis to parameterise the unknown inertial transport and convective source term in the dynamic equation for the three-dimensional spectrum. The non-linear integro-differential equation is ...
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An investigation of the urban heat island of Rome through a canyon–based subgrid scheme
This paper describes some modifications to a mesoscale model surface scheme to better account for urban heat–storage. The approach involves integrating the Subgrid Town Energy Budget (STEB) with the Regional Atmospheric Modelling System (RAMS). The integrated system has been applied to the investigation of the Urban Heat Island (UHI) of Rome, Italy, and the surrounding area (Lazio Region), ...
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Air dispersion modelling for individual exposure studies
The concentration fluctuations of a dispersing hazardous gaseous pollutant in the atmospheric boundary layer, and the hazard associated with short–term concentration levels, demonstrate the necessity of estimating the magnitude of these fluctuations using predicting models. To predict and estimate the maximum expected dosage and the exposure time within which the dosage exceeds certain health ...
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A model evaluation exercise for non-buoyant releases from continuous point sources
A model of the dispersion of pollutants released from a continuous point source into the atmospheric boundary layer is suggested. For this model and for that of Gryning et al. (1987), the predicted normalised crosswind integrated concentrations are compared with observational data. The data obtained in diffusion experiments with a non-depositing tracer, in non-buoyant releases carried out at ...
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Evaluation of the Gaussian puff model based on measurements
Concentrations calculated with the Gaussian puff model have been compared with measurements obtained from the dispersion experiments conducted at Lillestrom, Copenhagen, and Kincaid. The following dispersion parameters were used in the Gaussian puff model: Pasquill-Gifford, Briggs, Brookhaven and OML. Comparisons of the calculated and measured values of the concentrations have been carried out ...
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Modelling the influence of dimethyl sulphide on aerosol production in the marine boundary layer
It has been postulated that dimethyl sulphide (DMS) emissions from the oceans can produce new condensation nuclei and eventually cloud condensation nuclei. Thus, DMS may have a significant influence on the Earth's radiation budget. A study of this postulate has been conducted for marine boundary layer conditions using a newly developed chemistry–aerosol–cloud (CAC) modelling system. The CAC ...
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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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CFD modelling for atmospheric pollutants/aerosols studies within the complex terrains of urban areas and industrial sites
Computational fluid dynamic (CFD) modelling of pollution dispersion and chemical conversion to aerosol particles in the atmospheric boundary layer (ABL) has been studied. The investigation focused on the numerical modelling above complex orographic terrains of urban areas and industrial sites including the dispersion of toxic substances in the air as a result of accidents. A finite-rate model of ...
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Uncertainties in the meteorological input of the chemistry-transport models and some examples of their consequences
In this article, selected weather prediction model parameters, which are important for air pollution studies, were verified against measurements at two sounding stations in Finland. In 1996–1998, the short-time model-measurement differences were rather high. The friction velocity was on average overestimated by 30–70%, the mixing height during spring months was underestimated by up to 60%, 2 m ...
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ADMS 5 Flat Terrain Validation Kincaid, Indianapolis and Prairie Grass
1 Introduction This document presents a summary of ADMS model results compared against three well known field data sets: Prairie Grass. Kincaid and Indianapolis. Results are also presented for two U.S. models: ISCST and AERMOD. ISC ST is the United States Environmental Protection Agency model. It is a so-called 'old generation' model, similar to the UK R-91 model, based on the 1970's ...
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Atmospheric environmental impact assessment modelling in France
The most widely accepted model of atmospheric dispersion for impact assessment in France is the Gaussian model of Doury. The Centre d'Etudes Atomiques (CEA) and Electricite de France (EDF) have developed their own software systems, which include several compatible or nested meteorological, trajectory, and dispersion codes. These systems are fitted to the various atmospheric scales from regional ...
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A 2-D meteorological pre-processor for real-time 3-D ATD models
Horizontal non-uniformity has important effects on the structure of the atmospheric boundary layer and, consequently, on pollutant transport and dispersion. These effects can be dominant in coastal sites or in the presence of complex terrain. Advanced 3-D atmospheric dispersion models can be used to calculate short-term pollutant concentrations in such complex situations. The use of new ...
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Dispersion of a passive pollutant in the vicinity of a U-shaped building
The three-dimensional microscale numerical model MIMO was applied to calculate the dispersion of a passive pollutant in the vicinity of a U-shaped building. Three different locations of a non-buoyant source and six different wind directions were examined. The calculated concentrations were compared with concentrations measured in a boundary layer wind tunnel. The comparison shows a very good ...
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Application of meteorological pre-processor for next generation dispersion models for Hungary
Research has been started by Hungarian regulatory modellers for the preparation of next generation dispersion models applied in EIA studies. This new generation will require advanced planetary boundary layer parameters in Gaussian plume models. The author investigated the validation of the meteorological pre-processor TRIP for Hungary.Keywords: meteorological pre-, processors, atmospheric ...
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