Similarity Scaling Of Surface-Released Smoke Plumes

• Published in: Boundary-layer meteorology 2002-12, Vol.105 (3), p.483-505
• Main Authors: Mikkelsen, Torben, Jørgensen, Hans E., Nielsen, Morten, Ott, Søren
• Format: Article
• Language: English
• Subjects: Aerosols; Boundary layer; Lidar; Plumes
• ISSN: 0006-8314; 1573-1472
• DOI: 10.1023/A:1020380820526

Concentration fluctuation data from surface-layer released smokeplumes have been investigated with the purpose of finding suitable scaling parametersfor the corresponding two-particle, relative diffusion process.Dispersion properties have been measured at downwind ranges between 0.1 and 1 km from a continuous, neutrally buoyant ground level source. A combinationof SF^sub 6^ and chemical smoke (aerosols) was used as tracer. Instantaneous crosswind concentration profiles of high temporal (up to 55 Hz) and spatialresolution (down to 0.375 m) were obtained from aerosol-backscatter Lidar detectionin combination with simultaneous gas chromatograph (SF^sub 6^) reference measurements. The database includes detailed crosswind concentration fluctuation measurements. Each experiment, typically of 1/2-hour duration, containsplume mean and variance concentration profiles, intermittency profiles andexceedence and duration statistics. The diffusion experiments were accompanied by detailed in-situ micrometeorological mean and turbulence measurements. In this paper, a new distance-neighbour function for surface-released smoke plumes is proposed, accompanied by experimental evidence in its support. The new distance-neighbour function is found to scale with the surface-layer friction velocity,and not with the inertial subrange dissipation rate, over the range of distance-neighbour separations considered.[PUBLICATION ABSTRACT]