Abstract
Measurements have been made of concentration fluctuations in a dispersing plume from an elevated point source in the atmospheric surface layer using a recently developed fast-response photoionization detector. This detector, which has a frequency response (−6 dB point) of about 100 Hz, is shown to be capable of resolving the fluctuation variance contributed by the energetic subrange and most of the inertial-convective subrange, with a reduction in the fluctuation variance due to instrument smoothing of the finest scales present in the plume of at most 4%.
Concentration time series have been analyzed to obtain the statistical characteristics of both the amplitude and temporal structure of the dispersing plume. We present alongwind and crosswind concentration fluctuation profiles of statistics of amplitude structure such as total and conditional fluctuation intensity, skewness and kurtosis, and of temporal structure such as intermittency factor, burst frequency, and mean burst persistence time. Comparisons of empirical concentration probability distributions with a number of model distributions show that our near-neutral data are best represented by the lognormal distribution at shorter ranges, where both plume meandering and fine-scale in-plume mixing are equally important (turbulent-convective regime), and by the gamma distribution at longer ranges, where internal structure or spottiness is becoming dominant (turbulent-diffusive regime). The gamma distribution provides the best model of the concentration pdf over all downwind fetches for data measured under stable stratification. A physical model is developed to explain the mechanism-induced probabilistic schemes in the alongwind development of a dispersing plume, that lead to the observed probability distributions of concentration. Probability distributions of concentration burst length and burst return period have been extracted and are shown to be modelled well with a powerlaw distribution. Power spectra of concentration fluctuations are presented. These spectra exhibit a significant inertial-convective subrange, with the frequency at the spectral peak decreasing with increasing downwind fetch. The Kolmogorov constant for the inertial-convective subrange has been determined from the measured spectra to be 0.17±0.03.
Similar content being viewed by others
References
Bara, B. M., Wilson, D. J., and Zelt, B. W.: 1992, ‘Concentration Fluctuation Profiles from a Water Channel Simulation of a Ground-Level Release’,Atmos. Enriron. 26A, 1053–1062.
Biltoft, C. A.: 1991, ‘Concentration Fluctuation Modeling of Chemical Hazards (Field Test)’, U.S. Army Dugway Proving Ground, Dugway, Utah, 96 pp.
Chandler, G. M.: 1991, ‘Development of Fast-Response Tracer Gas Sensors for Use in Full-Scale Atmospheric Dispersion Field Trials. Part I: Hardware Component. Part II: Field Testing Component’, Technical Report for Defence Research Establishment Suffield (DRES-CR-04-92), S & J Engineering, Scarborough, Ontario, 82 pp.
Chatwin, P. C. and Sullivan, P. J.: 1979, ‘The Relative Diffusion of a Cloud of Passive Contaminant in Incompressible Turbulent Flow’,J. Fluid Mech. 91, 337–355.
Chatwin, P. C. and Sullivan, P. J.: 1990, ‘A Simple and Unifying Physical Interpretation of Scalar Fluctuation Meaurements From Many Turbulent Shear Flows’,J. Fluid Mech. 212, 533–556.
Csanady, G. T.: 1973,Turbulent Diffusion in the Environment, D. Reidel Publishing Company, Dordrecht, Holland.
Deardorff, J. W. and Willis, G. E.: 1984, Ground-level Concentration Fluctuations From a Buoyant and Non-buoyant Source Within a Laboratory Convective Mixed Layer’,Atmos. Environ. 18, 1297–1309.
Dinar, N., Kaplan, H., and Kleiman, M.: 1988, ‘Characterization of Concentration Fluctuations of a Surface Plume in a Neutral Boundary Layer’,Boundary-Layer Meteorol. 45, 157–175.
Durbin, P. A.: 1980, ‘A Stochastic Model of Two Particle Dispersion and Concentration Fluctuations in Homogeneous Turbulence’,J. Fluid Mech. 100, 279–302.
Fackrell, J. E. and Robins, A. G.: 1982a, ‘Concentration Fluctuations and Fluxes in Plumes from Point Sources in a Turbulent Boundary Layer’,J. Fluid Mech. 117, 1–26.
Fackrell, J. E. and Robins, A. G.: 1982b, ‘The Effect of Source Size on Concentration Fluctuations in Plumes’,Boundary-Layer Meteorol. 22, 335–350.
Hanna, S. R.: 1984, ‘The Exponential Probability Density Function and Concentration Fluctuations in Smoke Plumes’,Boundary-Layer Meteorol. 29, 361–375.
Hanna, S. R.: 1986, ‘Spectra of Concentration Fluctuations: The Two Time Scales of a Meandering Plume’,Atmos. Environ. 20, 1131–1137.
Hanna, S. R. and Insley, E. M.: 1989, ‘Time Series Analysis of Concentration and Wind Fluctuations’,Boundary-Layer Meteorol. 47, 131–147.
Jones, C. D.: 1983, ‘On the Structure of Instantaneous Plumes in the Atmosphere’,J. Haz. Mat. 7, 87–112.
Kaplan, H. and Dinar, N.: 1988 ‘A Stochastic Model for Dispersion and Concentration Distribution in Homogeneous Turbulence’,J. Fluid Mech. 190, 121–140.
Lewellen, W. S. and Sykes, R. I.: 1986, ‘Analysis of Concentration Fluctuations from LIDAR Observations of Atmospheric Plumes’,J. Clim. and Appl. Meteorol. 25, 1145–1154.
Mylne, K. R. and Mason, P. J.: 1991, ‘Concentration Fluctuation Measurements in a Dispersing Plume at a Range of up to 1000 m’,Q. J. R. Meteorol. Soc. 117, 177–206.
Pasquill, F. and Smith, F. B.: 1983,Atmopheric Diffusion, Ellis Horwood, Chichester, England.
Sawford, B. L.: 1985, ‘Lagrangian Statistical Simulation of Concentration Mean and Fluctuation Fields’,J. Climate Appl. Met. 24, 1152–1166.
Sawford, B. L.: 1987, ‘Conditional Concentration Statistics for Surface Plumes in the Atmospheric Boundary Layer’,Boundary-Layer Meteorol. 38, 209–223.
Sawford, B. L., Frost, C. C., and Allan, T. C.: 1985, ‘Atmospheric Boundary-Layer Measurements of Concentration Statistics from Isolated and Multiple Sources’,Boundary-Layer Meteorol. 31, 249–268.
Stopountzis, H., Sawford, B. L., Hunt, J. C. R., and Britter, R. E.: 1986, ‘Structure of the Temperature Field Downwind of a Line Source in Grid Turbulence’,J. Fluid Mech. 165, 401–424.
Storebo, P. B.: 1983, ‘Concentration Pattern During Turbulent Dispersion’,Boundary-Layer Meteorol. 27, 359–370.
Thomson, D. J.: 1990, ‘A Stochatic Model for the Motion of Particle Pairs in Isotropic High-Reynolds-Number Turbulence, and its Application to the Problem of Concentration Variance’,J. Fluid Mech. 210, 113–153.
Wilson, D. J. and Simms, B. W.: 1985, ‘Exposure Time Effects on Concentration Fluctuations in Plumes’, Report No. 47, Department of Mechanical Engineering, University of Alberta, Edmonton, Canada, 162 pp.
Wilson, D. J., Zelt, B. W., and Pittman, W. E.: 1991, ‘Statistics of Turbulent Fluctuation of Scalars in a Water Channel’, Technical Report for Defence Research Establishment Suffield (DRES-CR-31-91), Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada, 60 pp.
Yee, E., Wilson, D. J., and Zelt, B. W.: 1993, ‘Probability Distributions of Concentration Fluctuations of a Weakly Diffusive Passive Plume in a Turbulent Boundary Layer’,Boundary-Layer Meteorol. 64 (in press).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Yee, E., Kosteniuk, P.R., Chandler, G.M. et al. Statistical characteristics of concentration fluctuations in dispersing plumes in the atmospheric surface layer. Boundary-Layer Meteorol 65, 69–109 (1993). https://doi.org/10.1007/BF00708819
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00708819