Applications in Air Pollution Modeling

Hanna, Steven R.

doi:10.1007/978-94-010-9112-1_7

Cited by 122 publications

(211 citation statements)

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“…The derivation gotten through the parameters of Hanna (Hanna, 1982) is based on the Taylor's Statistical Diffusion Theory, in accordance with Batchelor (1949), and therefore is presented in the following form:…”

Section: Methodsmentioning

confidence: 99%

“…According Hanna (1982), the following vertical profiles of σ 2 w and T w for a convective boundary layer are proposed:…”

Section: Methodsmentioning

confidence: 99%

“…Similar to convective case, that is, by means of Taylor's Theory (Taylor, 1921;Batchelor, 1949), neutral eddy diffusivities can be obtained from neutral parameters from Hanna (Hanna, 1982).…”

Section: Methodsmentioning

confidence: 99%

“…This fact motivated the accomplishment of this study. Specifically, the aim of this work is evaluate which coefficient formulation for convective conditions -basically Hostlag & Moeng (1991), Degrazia et al (1997) and Hanna (1982) -and for neutral conditions -Degrazia et al (1997) and Hanna (1982) -is able to better simulate the pollutant concentration.…”

Section: Introductionmentioning

confidence: 99%

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Turbulent Eddy Diffusivities for a Planetary Boundary Layer Generated by Thermal and Mechanical Effects

Nunes¹,

Degrazia²,

Campos³

et al. 2013

Rev. Bras. Geof.

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ABSTRACT.To estimate the superficial concentration of contaminants an eulerian model of dispersion was used, where the main scheme is the diffusion-advection equation that employs turbulent eddy diffusivity. The aim of this work is a comparison between different eddy diffusivity derivations for a planetary boundary layer turbulence generated by thermal and mechanical effects. The accuracy of eddy diffusivity derivations was evaluated by comparing the data simulated in the eulerian dispersion model and the observed concentrations of the Copenhagen and Praire Grass experiments. Three convective eddy diffusivity derivations were compared among themselves: 1) proposed by Degrazia et al., 2) proposed Hostlag & Moeng and 3) the derivation gotten by the parameters of Hanna. Two neutral eddy diffusivity derivations were also compared: 1) proposed by Degrazia et al. and 2) gotten by the parameters of Hanna. In order to improve the comparisons some adjustments and increments were made in Hostlag & Moeng derivation and in that gotten by the parameters of Hanna. We can observe that despite the eddy diffusivities having been formulated by different ways, the results were similar and sufficiently satisfactory. In the convective case, the best simulations of each derivation showed a RESUMO. Na estimativa da concentração superficial de contaminantes foi usado um modelo de dispersão euleriano, tendo como esquema principal a equação de difusão-advecção que emprega coeficiente de difusão turbulento. O objetivo deste trabalhoé a comparação entre diferentes derivações de coeficientes de difusão para uma camada limite planetária cuja turbulênciaé gerada por fatores térmicos e mecânicos. A precisão das derivações foi calculada por meio da comparação entre os dados simulados pelo modelo euleriano de dispersão e os dados de concentração observados nos experimentos de Copenhagen e Praire Grass. Três derivações de coeficientes de difusão convectivos foram comparadas: 1) a proposta por Degrazia et al., 2) a proposta por Hostlag & Moeng, e 3) a derivação obtida através dos parâmetros de Hanna. Também foram comparadas duas derivações de coeficientes de difusão neutros: 1) uma proposta por Degrazia et al. e 2) a obtida por meio dos parâmetros de Hanna. Para uma melhor comparação, foram feitos alguns ajustes nas derivações de Hostlag e Moeng e na obtida através dos parâmetros de Hanna.Pode-se observar que apesar das derivações serem obtidas por diferentes metodologias, os resultados foram similares e suficientemente satisfatórios. Para o caso convectivo, as melhores simulações de cada derivação apresentaram Erro Quadrático Médio Normalizado entre 0,04 e 0,05 quando comparados com os dados do experimento de Copenhagen.Palavras-chave: modelo de dispersão, teoria de Taylor, escala de tempo lagrangeana.

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Section: Methodsmentioning

confidence: 99%

“…According Hanna (1982), the following vertical profiles of σ 2 w and T w for a convective boundary layer are proposed:…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Turbulent Eddy Diffusivities for a Planetary Boundary Layer Generated by Thermal and Mechanical Effects

Nunes¹,

Degrazia²,

Campos³

et al. 2013

Rev. Bras. Geof.

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“…Turbulent strengths were diagnosed from meteorological fields (Sect. 3.2) using the Hanna scheme (Hanna, 1982). The…”

Section: Transport and Diffusionmentioning

confidence: 99%

Modeling atmospheric ammonia and ammonium using a stochastic Lagrangian air quality model (STILT-Chem v0.7)

et al. 2013

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Abstract.A new chemistry module that simulates atmospheric ammonia (NH 3 ) and ammonium (NH + 4 ) was incorporated into a backward-in-time stochastic Lagrangian air quality model (STILT-Chem) that was originally developed to simulate the concentrations of a variety of gas-phase species at receptors. STILT-Chem simulates the transport of air parcels backward in time using ensembles of fictitious particles with stochastic motions, while accounting for emissions, deposition and chemical transformation forward in time along trajectories identified by the backward-in-time simulations. The incorporation of the new chemistry module allows the model to simulate not only gaseous species, but also multi-phase species involving NH 3 and NH were compared with observations, which show broad agreement between simulated concentrations and observations. Since the model is based on back trajectories, the influence of each major process such as emission, deposition and chemical conversion on the concentration of a modeled species at a receptor can be determined for every upstream location at each time step. This makes it possible to quantitatively investigate the upstream processes affecting receptor concentrations. The modeled results suggest that the concentrations of NH 3 at those sites were significantly and frequently affected by Ohio, Iowa, Minnesota, Michigan, Wisconsin, southwestern Ontario and nearby areas. NH 3 is mainly contributed by emission sources whereas particulate NH + 4 is mainly contributed by the gas-to-aerosol chemical conversion of NH 3 . Dry deposition is the largest removal process for both NH 3 and particulate NH + 4 . This study revealed the contrast between agricultural versus forest sites. Not only were emissions of NH 3 higher, but removal mechanisms (especially chemical loss for NH 3 and dry deposition for NH + 4 ) were less efficient for agricultural sites. This combination explains the significantly higher concentrations of NH 3 and particulate NH + 4 observed at agricultural sites.

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Parallel computation of atmospheric pollutant dispersion under unstably stratified atmosphere

Liu

Leung

1998

Int. J. Numer. Meth. Fluids

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Applications in Air Pollution Modeling

Cited by 122 publications

References 0 publications

Turbulent Eddy Diffusivities for a Planetary Boundary Layer Generated by Thermal and Mechanical Effects

Turbulent Eddy Diffusivities for a Planetary Boundary Layer Generated by Thermal and Mechanical Effects

Modeling atmospheric ammonia and ammonium using a stochastic Lagrangian air quality model (STILT-Chem v0.7)

Parallel computation of atmospheric pollutant dispersion under unstably stratified atmosphere

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