Dispersion in atmospheric convective boundary layer with wind shears: from laboratory models to complex simulation studies

A review will be presented of recent advances in laboratory, numerical, and combined model studies of passive gaseous tracer dispersion in the atmospheric convective boundary layer (CBL) with surface and elevated wind shears. Atmospheric measurement data available for validation of the reviewed model techniques will be touched upon as well. The growing complexity of dispersion phenomena investigated and model approaches applied will be discussed in a historical retrospective. Contributions of Erich Plate to wind tunnel studies of atmospheric dispersion will be overviewed. Results from model studies of tracer dispersion in two CBL types, the (i) non-steady, horizontally inhomogeneous CBL and (ii) quasi-stationary, horizontally heterogeneous CBL, will be analyzed. The discussion will be focused on the dispersion of non-buoyant plume emitted from a point source located at different elevations within the CBL. Basic modeling approaches employed in different laboratory facilities (water tanks and wind tunnels) will be described. The reviewed numerical techniques will include Large Eddy Simulation (LES) and Lagrangian modeling. It will be demonstrated how high-resolution numerical simulation combined with laboratory modeling opens new horizons in understanding of dispersion processes in the CBL and their parameterization in applied air-pollution models.