An Integral Formulation for the Dispersion Parameters in a Shear–Buoyancy-Driven Planetary Boundary Layer for Use in a Gaussian Model for Tall Stacks

An alternative formulation for the dispersion parameters in a convective boundary layer is presented. The development consists of a simple algebraic relation for the dispersion parameters, originated from the fitting of experimental data, in which the turbulent velocity variances and the Lagrangian decorrelation time scales are derived from the turbulent kinetic energy convective spectra. Assuming homogeneous turbulence for elevated regions in an unstable planetary boundary layer (PBL), the present approach, which provides the dispersion parameters, has been compared to the observational data as well as to results obtained by classical complex integral formulations. From this comparison yields that the vertical and lateral dispersion parameters obtained from the simple algebraic formulas reproduce, in an adequate manner, the spread of contaminants released by elevated continuous source in an unstable PBL. Therefore, the agreement with dispersion parameters available by an integral formulation indicates that the hypothesis of using an algebraic formulation as a surrogate for dispersion parameters in the turbulent convective boundary layer is valid. In addition, the algebraic vertical and lateral dispersion parameters were introduced into an air pollution Gaussian diffusion model and validated with the concentration data of Copenhagen experiments. The results of such Gaussian model, incorporating the algebraic dispersion parameters, are shown to agree with the measurements of Copenhagen.

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A New Direction in the Atmospheric Pollutant Dispersion inside the Planetary Boundary Layer

Journal of Applied Meteorology and Climatology ◽

10.1175/jamc-d-17-0254.1 ◽

2018 ◽

Vol 57 (1) ◽

pp. 185-192 ◽

Cited By ~ 6

Author(s):

Davidson Moreira ◽

Marcelo Moret

Keyword(s):

Boundary Layer ◽

Fractional Derivative ◽

Planetary Boundary Layer ◽

Atmospheric Dispersion ◽

Gaussian Model ◽

Pollutant Dispersion ◽

Atmospheric Pollutant ◽

Advection Diffusion Equation ◽

Laplace Transform Technique ◽

Better Than

AbstractIn this study, an analytical solution for the steady-state fractional advection–diffusion equation was obtained to simulate the atmospheric dispersion of pollutants in a vertically inhomogeneous planetary boundary layer. The authors propose a method that uses the modified generalized integral Laplace transform technique to solve the transformed problem with a fractional derivative, resulting in a more general solution. The model results were compared with the fractional Gaussian model and demonstrate that, when considering an experimental dataset under moderately unstable conditions, fractional-derivative models perform better than traditional integer-order models.

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Employing Spectral Analysis to Obtain Dispersion Parameters in an Atmospheric Environment Driven by a Mesoscale Downslope Windstorm

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph182413027 ◽

2021 ◽

Vol 18 (24) ◽

pp. 13027

Author(s):

Cinara Ewerling da Rosa ◽

Michel Stefanello ◽

Silvana Maldaner ◽

Douglas Stefanello Facco ◽

Débora Regina Roberti ◽

...

Keyword(s):

Boundary Layer ◽

Planetary Boundary Layer ◽

Diffusion Theory ◽

Dispersion Model ◽

Atmospheric Dispersion ◽

Particle Dispersion ◽

Atmospheric Environment ◽

Dispersion Parameters ◽

Simulated Concentration ◽

Four Levels

Considering the influence of the downslope windstorm called “Vento Norte” (VNOR; Portuguese for “North Wind”) in planetary boundary layer turbulent features, a new set of turbulent parameterizations, which are to be used in atmospheric dispersion models, has been derived. Taylor’s statistical diffusion theory, velocity spectra obtained at four levels (3, 6, 14, and 30 m) in a micrometeorological tower, and the energy-containing eddy scales are used to calculate neutral planetary boundary layer turbulent parameters. Vertical profile formulations of the wind velocity variances and Lagrangian decorrelation time scales are proposed, and to validate this new parameterization, it is applied in a Lagrangian Stochastic Particle Dispersion Model to simulate the Prairie Grass concentration experiments. The simulated concentration results were shown to agree with those observed.

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Modelling Dispersion Parameters in a Planetary Boundary Layer Dominated by Convection

Air Pollution Modeling and Its Application XII ◽

10.1007/978-1-4757-9128-0_81 ◽

1998 ◽

pp. 715-716 ◽

Cited By ~ 1

Author(s):

G. A. Degrazia

Keyword(s):

Boundary Layer ◽

Planetary Boundary Layer ◽

Dispersion Parameters

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Dispersion of Particles Released into a Neutral Planetary Boundary Layer Using a Markov Chain–Monte Carlo Model

Journal of Applied Meteorology ◽

10.1175/jam2249.1 ◽

2005 ◽

Vol 44 (7) ◽

pp. 1106-1115 ◽

Cited By ~ 6

Author(s):

R. Avila ◽

S. S. Raza

Keyword(s):

Boundary Layer ◽

Monte Carlo ◽

Markov Chain ◽

Markov Chain Monte Carlo ◽

Planetary Boundary Layer ◽

Monte Carlo Model ◽

Measurement Data ◽

Gaussian Model ◽

Neutral Atmosphere ◽

Numerical Predictions

Abstract The dispersion and concentration of particles (fluid elements) that are continuously released into a neutral planetary boundary layer is presented. The velocity fluctuations of the particles are generated using a Markov chain–Monte Carlo (MCMC) process at random time intervals with a one-step memory. The local mean concentration of the particles is calculated by using a fully Lagrangian method, which performs an efficient near-neighbor search and employs a smoothing kernel for eliminating the statistical noise. The predicted vertical and transversal root-mean-square of the particles’ deviation from their mean position [()1/2 and ()1/2] for an elevated continuous release source in a neutral atmosphere are compared with empirical parameters like the Pasquill–Gifford σz and σy. The numerical predictions of the particle concentration are compared with a Gaussian model and field measurement data on the ground concentration obtained during the Green Glow Program. The comparison between the numerical predictions and the field data shows that the MCMC model can successfully predict the particle dispersion and concentration in a neutral atmosphere.

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Lagrangian simulation of the passive tracer in the convective planetary boundary layer

Proceeding of THMT-15. Proceedings of the Eighth International Symposium On Turbulence Heat and Mass Transfer ◽

10.1615/ichmt.2015.thmt-15.1460 ◽

2015 ◽

Author(s):

Boris B. Ilyushin ◽

I.V Mitin ◽

Dmitrii Ph. Sikovsky

Keyword(s):

Boundary Layer ◽

Planetary Boundary Layer ◽

Passive Tracer ◽

Lagrangian Simulation ◽

Convective Planetary Boundary Layer

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Sensitivity of an Idealized Tropical Cyclone to the Configuration of the Global Forecast System–Eddy Diffusivity Mass Flux Planetary Boundary Layer Scheme

Atmosphere ◽

10.3390/atmos12020284 ◽

2021 ◽

Vol 12 (2) ◽

pp. 284

Author(s):

Evan A. Kalina ◽

Mrinal K. Biswas ◽

Jun A. Zhang ◽

Kathryn M. Newman

Keyword(s):

Boundary Layer ◽

Planetary Boundary Layer ◽

Weather Prediction ◽

Intensity Change ◽

Rapid Intensification ◽

Forecast System ◽

Stability Functions ◽

Non Local ◽

The Stability ◽

Heat And Moisture

The intensity and structure of simulated tropical cyclones (TCs) are known to be sensitive to the planetary boundary layer (PBL) parameterization in numerical weather prediction models. In this paper, we use an idealized version of the Hurricane Weather Research and Forecast system (HWRF) with constant sea-surface temperature (SST) to examine how the configuration of the PBL scheme used in the operational HWRF affects TC intensity change (including rapid intensification) and structure. The configuration changes explored in this study include disabling non-local vertical mixing, changing the coefficients in the stability functions for momentum and heat, and directly modifying the Prandtl number (Pr), which controls the ratio of momentum to heat and moisture exchange in the PBL. Relative to the control simulation, disabling non-local mixing produced a ~15% larger storm that intensified more gradually, while changing the coefficient values used in the stability functions had little effect. Varying Pr within the PBL had the greatest impact, with the largest Pr (~1.6 versus ~0.8) associated with more rapid intensification (~38 versus 29 m s−1 per day) but a 5–10 m s−1 weaker intensity after the initial period of strengthening. This seemingly paradoxical result is likely due to a decrease in the radius of maximum wind (~15 versus 20 km), but smaller enthalpy fluxes, in simulated storms with larger Pr. These results underscore the importance of measuring the vertical eddy diffusivities of momentum, heat, and moisture under high-wind, open-ocean conditions to reduce uncertainty in Pr in the TC PBL.

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