A Box Model to Evaluate Dry Particle Deposition on Urban Areas: Comparison of two Dry Deposition Velocities Parameterization

The AERBOX multilayer box model aimed to evaluate dry deposition of particulate and gaseous pollutants on monumental urban areas has been used for a case study involving the area of Florence and Prato. The case study has shown as all model outputs involving deposition, namely deposition velocities, concentration averaged deposition velocities, deposition fluxes and dimension spectrum and chemical composition of deposited matter, depend strongly on the choice of the deposition parameterization applied, the discrepancies reaching an order of magnitude in some cases, as for urban canopies. Both deposition parameterizations are routinely employed, or are going to be implemented, in some national deposition models. Discrepancies such the ones shown suggest that the deposition algorithms employed in regulatory models, as AERBOX is aimed to be in the future, should be chosen with great care, especially if the model is intended to be applied in urban areas, where the deposition phenomenology is complex.