About this Journal Submit a Manuscript Table of Contents
Advances in Meteorology
Volume 2014 (2014), Article ID 760393, 12 pages
http://dx.doi.org/10.1155/2014/760393
Research Article

Correlation of Dry Deposition Velocity and Friction Velocity over Different Surfaces for PM2.5 and Particle Number Concentrations

Istituto di Scienze dell’Atmosfera e del Clima, ISAC-CNR, U.O.S. di Lecce, Strada Provinciale Lecce-Monteroni km 1.2, 73100 Lecce, Italy

Received 6 March 2014; Accepted 18 May 2014; Published 1 June 2014

Academic Editor: Carlos Borrego

Copyright © 2014 Antonio Donateo and Daniele Contini. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Dry deposition of particles is an important way of aerosol removal from the atmosphere and a key process in surface-atmosphere exchanges. The deposition velocities, Vd, are often parameterised in air quality and climate modelling as function of the friction velocity, , atmospheric stability, and particle size (if size-segregated information is available). In this work, a study of the correlation between Vd and over different surfaces is presented for both PM2.5 and particle number fluxes. Results indicate an almost linear increase of Vd with with slopes similar for PM2.5 fluxes and particle number fluxes over the different surfaces analysed. This means that the ratios Vd/ tend to collapse over similar values even if Vd and are significantly different because take into account most of the surface effects. There is a limited difference between stable cases and unstable/neutral cases with slightly lower deposition velocities in stable cases for fixed values of . The average value of Vd/ is 0.010 ± 0.0017 (median 0.0062 ± 0.0015) (considering all stabilities) and 0.0097 ± 0.002 (median 0.005 ± 0.001) for stable cases. This could be the base for an empirical parameterisation of deposition velocities in air quality models.