"An LPDM tracks a set of tracer particles either forward in time from a source region or backward in time from a measurement location (receptor). Each particle is transported by advective wind fields (obtained from a meteorological model) plus an unresolved turbulent (subgrid) velocity component." ( Hegarty et al., 2013: Evaluation of Lagrangian Particle Dispersion Models with Measurements from Controlled Tracer Releases. J. Appl. Meteor. Climatol., 52, 2623–2637. )