GRAL (Graz Lagrangian Model)

GRAL, together with the GRAMM wind field model, computes dispersion of non-reactive pollutants from sources such as roads, stacks and road tunnel portals. It is especially suited to low wind speeds and complex terrain, and an integrated micro-scale flow model accounts for the effect of buildings on dispersion. It also handles dry and wet deposition, odour hours and stack emissions with exit temperature and velocity, in steady-state or transient mode. It is used in air quality impact assessments and research. Limitation: downloading requires registration, and running the model needs training and suitable meteorological data.