Simulation of atmospheric dispersion in the convective boundary layer: comparison between two Lagrangian particle models

The results obtained in convective boundary layer dispersion by two Lagrangian particle models (according to Thomson's 1984 and 1987 papers) are compared. First, the sensitivity of the two models in accounting for the third-order moment of vertical wind speed fluctuations has been assessed, considering homogeneous non-Gaussian turbulence. Then, the ability of the two models to simulate the ground-level concentration field has been tested, by comparing their predictions with tracer data measured in two experiments. The first is one of the well-known water tank experiments performed by Willis and Deardorff in 1978, the second is the Katrex field experiment (Thomas et al., 1983). The results obtained in the case of the controlled conditions seem to recommend the use of the model based on Thomson's 1987 paper, whereas the performances of both models are comparable in simulating a real case.