Evaluation of atmospheric dilution factors for effluents diffused from an
                        elevated continuous point source

Bultynck, H.; Malet, L. M.

doi:10.3402/tellusa.v24i5.10659

Cited by 42 publications

(10 citation statements)

References 3 publications

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“…The plume height is here set externally as a forcing term h t ¼ h u t , based on the theoretical formulae for buoyant plume rise by Briggs (13) . Similarly, in both models s y and s z are set externally using a site-specific parameterisation of the dispersion parameters (14) , for example, s y;t ¼ s u y;t , that depends on the distance from the source and the atmospheric stability according to the Pasquill-Gifford scheme (15) . A simple random walk process is used to govern the temporal variations of the remaining (free) state variables, cf.…”

Section: Numerical Resultsmentioning

confidence: 99%

Analysis of a Kalman filter based method for on-line estimation of atmospheric dispersion parameters using radiation monitoring data

Drews

Lauritzen

Madsen

2004

Radiation Protection Dosimetry

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A Kalman filter method is discussed for on-line estimation of radioactive release and atmospheric dispersion from a time series of off-site radiation monitoring data. The method is based on a state space approach, where a stochastic system equation describes the dynamics of the plume model parameters, and the observables are linked to the state variables through a static measurement equation. The method is analysed for three simple state space models using experimental data obtained at a nuclear research reactor. Compared to direct measurements of the atmospheric dispersion, the Kalman filter estimates are found to agree well with the measured parameters, provided that the radiation measurements are spread out in the cross-wind direction. For less optimal detector placement it proves difficult to distinguish variations in the source term and plume height; yet the Kalman filter yields consistent parameter estimates with large associated uncertainties. Improved source term assessment results, when independent estimates of the plume height can be used. Perspectives for using the method in the context of nuclear emergency management are discussed, and possible extensions to the present modelling scheme are outlined, to account for realistic accident scenarios.

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Section: Numerical Resultsmentioning

confidence: 99%

Analysis of a Kalman filter based method for on-line estimation of atmospheric dispersion parameters using radiation monitoring data

Drews

Lauritzen

Madsen

2004

Radiation Protection Dosimetry

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“…The second tower of the Belgian Nuclear Research Centre (SCK•CEN) is 120 m high and located in Mol (Geographical coordinates: 51 • 13'04"N and 5 • 05'24"E). Measurements have been done in the framework of determining atmospheric stability according to the turbulence scheme of SCK•CEN (Bultynck and Malet, 1972). It is placed in a rural area on flat terrain with pine trees in the immediate vicinity.…”

Section: Tower Observationsmentioning

confidence: 99%

Efficient urban canopy parametrization for atmospheric modelling: description and application with the COSMO-CLM model (version 5.0_clm6) for a Belgian Summer

Wouters¹,

Demuzere²,

Blahak³

et al. 2016

Preprint

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Abstract. This paper presents the Semi-empirical URban-canopY parametrization SURY, which bridges the gap between bulk urban land-surface schemes and explicit-canyon schemes. Based on detailed observational studies, modelling experiments and available parameter inventories, it offers a robust translation of urban canopy parameters containing the three-dimensional information into bulk parameters. It is extremely suitable for an intrinsic representation of canopy-dependent urban physics in existing bulk urban land-surface schemes of atmospheric models. At the same time, it delivers high efficiency in terms of computational cost for long-term climate modelling and numerical weather prediction. SURY enables versatility and consistency in choosing between the urban canopy parameters from bottom-up inventories and bulk parameters from top-down estimates. SURY is tested for Belgium at 2.8 km resolution with the COSMO-CLM model (version 5.0_clm6) that is extended with the bulk urban land-surface scheme TERRA_URB (version 2). The model reproduces very well the urban heat islands observed from in-situ urban-climate observations, satellite imagery and tower observations, which is in contrast to the original COSMO-CLM model without an urban land-surface scheme. As an application of SURY, the sensitivity of the COSMO-CLM model in terms of land-surface temperatures, air temperatures and associated urban heat islands is quantified for the urban canopy parameter ranges from the Local Climate Zones classification system. On the one hand, their city-scale effect shows that additional urban canopy information has potential for improving regional atmospheric modelling. On the other hand, the model performance and its sensitivity to the different urban canopy parameters largely depend on the temperature quantity considered. Such an ambiguity demonstrates that a multi-variable model evaluation is a requirement for improving and comparing online urban atmospheric modelling strategies.

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“…From the Lidar measurements, horizontal and vertical plume dispersion parameters (σ y , σ z ) can be derived along with the mean position and elevation of the plume. In Figure 2, measured dispersion parameters for Friday October 5 are compared to two different model results: a) the SCK•CEN model, in which Pasquill-Gifford stability classes are determined from the wind speed at 69 m and potential temperature gradient over the range 8 m -114 m, and the diffusion parameters are calculated for each stability class (Bultynck and Malet, 1972); b) the RIMPUFF model in which the puff growth is calculated based on similarity scaling (Thykier-Nielsen et al, 2002;Astrup et al, 2001). Also this model uses the wind speed at 69 m and the temperature differences between 48 m and 78 m, in addition to an assumed surface roughness length of 1 m for the area in question.…”

Section: Plume Geometrymentioning

confidence: 99%

Atmospheric dispersion of argon-41 from a nuclear research reactor: measurement and modelling of plume geometry and gamma radiation field

Lauritzen

Astrup

Drews

et al. 2003

IJEP

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Evaluation of atmospheric dilution factors for effluents diffused from an elevated continuous point source

Cited by 42 publications

References 3 publications

Analysis of a Kalman filter based method for on-line estimation of atmospheric dispersion parameters using radiation monitoring data

Analysis of a Kalman filter based method for on-line estimation of atmospheric dispersion parameters using radiation monitoring data

Efficient urban canopy parametrization for atmospheric modelling: description and application with the COSMO-CLM model (version 5.0_clm6) for a Belgian Summer

Atmospheric dispersion of argon-41 from a nuclear research reactor: measurement and modelling of plume geometry and gamma radiation field

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