The objective of this research was to improve our understanding of dispersion in the planetary boundary layer (PBL) by extending our Lagrangian particle dispersion model (LPDM) to the stable boundary layer (SBL) and to PBLs interacting with vegetation canopies. The LPDM was driven by large-eddy simulations (LESs). For the SBL, dispersion simulations of a weakly stable PBL demonstrated the slow dispersion rate caused by the stable stratification and showed that ...