Parameterization of aerosol dry deposition velocities onto smooth and rough surfaces

Abstract

The velocities of aerosol deposition onto vertical and horizontal surfaces are needed for 2D and 3D calculations of aerosol transport and deposition in the urban and indoor environments. This paper analyzes the experimental results and semiempirical and theoretical models on dry deposition velocities. The features of the solution obtained by Zhao and Wu [(2006a). Modeling particle deposition from fully developed turbulent flow in ventilation duct. Atmospheric Environment, 40, 457–466] for the velocity of aerosol deposition onto smooth surfaces are analyzed, the integrals are approximated analytically. To treat the deposition onto rough surfaces, the results of Sehmel [(1973). Particle eddy diffusivities and deposition for isothermal flow and smooth surfaces. Journal of Aerosol Science, 4, 125–138]; Sehmel and Hodgson [(1978). A model for predicting dry deposition of particles and gases to environmental surfaces. PNL-SA-6721. Richland, WA: Battelle, Pacific Northwest Laboratory] are modified and represented in a unified manner for vertical and horizontal surfaces. Cross-comparison with data of Slinn [(1978) Parameterization for resuspension and for Wet and Dry Deposition of Particles and Gases for Use in Radiation Dose Calculations. Nucl.Safety, 19(2), 205–219.] and the model of Lai and Nazaroff [(2000). Modeling indoor particle deposition from turbulent flow onto smooth surfaces. Journal of Aerosol Science, 31, 463–476] allowed reconciliation between the theoretical and semiempirical approaches. Finally, an approximation to the aerosol dry deposition velocities is obtained in the form of convenient parameterization formulas covering a wide range of particle sizes 0.01 μ m ⩽ d ⩽ 1000 μ m and surface roughnesses z 0 ⩽ 10 cm .