Vertical Dispersion from Surface and Elevated Releases: An Investigation of a Non-Gaussian Plume Model

摘要

The vertical diffusion of a passive tracer released from surface and elevatedsources in a neutrally-stratified boundary layer has been studied by comparing field and laboratory experiments with a non-Gaussian K-theory model that assumes power-law profiles for the mean velocity and vertical eddy diffusivity. Several important differences between model predictions and experimental data were discovered: (1) the model overestimated ground-level concentrations from surface and elevated releases at distances beyond the peak concentrations; (2) the model overpredicted vertical mixing near elevated sources, especially in the upward direction; (3) the model-predicted exponent in the exponential vertical concentration profile for a surface release was smaller than the experimentally measured exponent. Model closure assumptions and experimental shortcomings were examined in order to account for the differences.