A concentration pdf for the relative dispersion of a contaminant plume in the atmosphere

• Published in: Boundary-layer meteorology Vol. 106; no. 3; pp. 411 - 436
• Main Authors: MUNRO, R. J, CHATWIN, P. C, MOLE, N
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01-03-2003; Springer Nature B.V
• Subjects: Boundary layers; Contaminants; Convection, turbulence, diffusion. Boundary layer structure and dynamics; Earth, ocean, space; Exact sciences and technology; External geophysics; Lidar; Mathematical models; Maximum entropy; Meteorology; Studies; Concentration fluctuations; Beta distribution; Relative dispersion; Method of maximum entropy; Plume; Maximum entropy inversion; Concentration fluctuation; Pareto distribution; Atmospheric boundary layer; Absolute dispersion; Radar observation; Probability density function; Lidar; Atmospheric dispersion; Contaminant; Concentration distribution
• ISSN: 0006-8314; 1573-1472
• DOI: 10.1023/A:1021209622648

Observations of the dispersion of a contaminant plume in theatmospheric boundary layer, obtained using a Lidar, are analysedin a coordinate frame relative to the instantaneous centre of massof the plume. To improve the estimates of relative dispersionstatistics, maximum entropy inversion is used to remove noise fromthe Lidar concentration profiles before carrying out the analysis.A parametric form is proposed for the probability density function(pdf) of concentration, consisting of a mixture of a betadistribution and of a generalised Pareto distribution (GPD). Thispdf allows for the possibility of a unimodal or bimodaldistribution, and is shown to give a satisfactory fit toobservations from a range of positions relative to the source. Thevariation of the fitted parameters with crossplume location isanalysed, and the maximum possible concentration is found todecrease away from the plume centre.[PUBLICATION ABSTRACT]