Evaluation of a new eddy diffusivity parameterisation from turbulent Eulerian spectra in different stability conditions

Mangia, Cristina; Moreira, Davidson Martins; Schipa, I.; Degrazia, Gervásio Annes; Tirabassi, T.; Rizza, Umberto

doi:10.1016/s1352-2310(01)00469-1

Cited by 46 publications

(27 citation statements)

References 23 publications

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“…The reliability of each model strongly depends on the way the turbulent parameters are calculated and is related to the current understanding of the ABL (Mangia et al, 2002). In order to calculate the three-dimensional concentration in the ground-level centerline concentration (Eq.…”

Section: Boundary Layer Parameterizationmentioning

confidence: 99%

A Semi-Analytical Dispersion Model From a Steady Source of Short Duration

Moreira

2014

CeN

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This paper presents a semi-analytical unsteady-state solution to the atmospheric dispersion equation for substancesCiência e Natura, v. 36 Ed. Especial, 2014, p. 149-159 150Atmospheric dispersion of pollutants has attracted attention of researchers in many ways. It adds have focused on the environmental impact and health hazards; others have worked on various modeling aspects such the meteorological conditions, dispersion mechanisms, removal mechanisms, topographical features, etc. Mathematical modeling has been the case of many of these studies. The importance and the need of mathematical modeling are well known in the scientific community. There are various modeling approaches that have been used effectively in the past to deal with air pollution dis-

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Section: Boundary Layer Parameterizationmentioning

confidence: 99%

A Semi-Analytical Dispersion Model From a Steady Source of Short Duration

Moreira

2014

CeN

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“…the value of the vertical eddy diffusivity, K z , we will use the parameterization that was suggested in paper Mangia et al (2002). In this parameterization the dependence of diffusivity on stability of ABL is introduced by means of the Obukhov-Monin length scale, L.…”

Section: Parameterization Of the Atmospheric Boundary Layermentioning

confidence: 99%

Formation of a large scale spot-like structure of the total deposition due to a powerful elevated finite source

2010

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Abstract. The process of formation of a large scale spot-like structure of the cumulative deposition pattern due to a powerful elevated finite lifetime source is studied using numerical solutions of a model diffusion problem. A possible cause of spottiness at regional scale, namely the diurnal cycle of the vertical turbulent mixing intensity in the atmospheric boundary layer, is investigated. It is shown that the atmospheric boundary layer diurnal cycle can cause the appearance of the spot-like structure when the source lifetime, t * , is much shorter than the diurnal period, T .

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“…Following Vilhena DEGRAZIA;VILHENA, 1999;DEGRAZIA;VILHENA, 2001;MANGIA et al, 2002), for a cartesian coordinate system in which the x direction coincides with that of the average wind, the steady-state advection-diffusion equation is written as in Arya (1995): (14) where c denotes the average concentration, U the mean wind speed in x direction and K x , K y and K z are the eddy diffusivities. The cross-wind integration of the equation (14) (neglecting the longitudinal diffusion) leads to:…”

Section: Air Pollution Modelmentioning

confidence: 99%

“…Although the diffusion coefficients presented by Batchelor (1949) were deduced originally for a homogeneous and stationary turbulent flow, they are used in regimes of stability that do not admit a homogeneity (case of the CBL) and they have if shown valid, because when used in dispersion models produce good results (MOREIRA et al, 1999;DEGRAZIA et al, 2001;MANGIA et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

Derivation of an eddy diffusivity depending on source distance under moderately unstable conditions

Goulart¹,

Moreira²,

Carvalho³

2002

Rev. Bras. Geof.

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Accounting for the current knowledge of the Convective Boundary Layer (CBL) structure and characteristics, a new formulation for eddy diffusivities has been derived, to be used in atmospheric dispersion models. Expressions are proposed for eddy diffusivities depending on source distance for inhomogeneous turbulence calculated directly with the Batchelor theory. The classical statistical diffusion theory, the observed spectral properties and the observed characteristics of energy-containing eddies are used to estimate these parameters. In addition, a vertical eddy diffusivity was introduced in an air pollution model and validated with the data of Copenhagen experiments and compared with the results of the obtained from classic formulation of the literature. A statistical evaluation show that, the results of the dispersion model with the K-parameterisation included, produces a good fit of the measured ground-level concentration data in the experimental conditions considered. Furthermore, the current work suggests that wind and eddy diffusivities profiles physically more realistic are important in regions near of an elevated source, and improves the description of the transport process of atmospheric pollutants.Keywords: eddy diffusivity; analytical model; inhomoheneous turbulence; Planetary Boundary Layer. RESUMOConsiderando-se o atual conhecimento sobre a estrutura e as características da Camada Limite Convectiva (CLC), foi obtida uma nova formulação geral para coeficientes de difusão para serem utilizados em modelos de dispersão atmosférica. Expressões são propostas para coeficientes de difusão dependentes da distância da fonte para turbulência não-homogênea, obtidas diretamente com a teoria de Batchelor. A teoria estatística de difusão clássica, as propriedades espectrais observadas e as características dos turbilhões mais energéticos são usados para estimar estes parâmetros. Além disso, o coeficiente de difusão vertical foi introduzido em um modelo de poluição do ar e validado com os dados experimentais de Copenhagen, além de comparado aos resultados de uma formulação clássica da literatura. Uma avaliação estatística mostra que os resultados do modelo de dispersão, utilizando a parametrização proposta, fornecem uma boa concordância com os dados de concentração superficiais nas condições experimentais consideradas. Adicionalmente, este trabalho sugere que perfis de vento e coeficientes de difusão mais reais são importantes em regiões próximas a uma fonte elevada, e melhoram a descrição do processo de transporte de poluentes atmosféricos.Palavras-chave: coeficiente de difusão; modelo analítico; turbulência não-homogênea; Camada Limite Planetária.

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Evaluation of a new eddy diffusivity parameterisation from turbulent Eulerian spectra in different stability conditions

Cited by 46 publications

References 23 publications

A Semi-Analytical Dispersion Model From a Steady Source of Short Duration

A Semi-Analytical Dispersion Model From a Steady Source of Short Duration

Formation of a large scale spot-like structure of the total deposition due to a powerful elevated finite source

Derivation of an eddy diffusivity depending on source distance under moderately unstable conditions

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