A parameterization of particle dry deposition has been developed fur the Ca
nadian Aerosol Module (CAM). This parameterization calculates particle dry
deposition velocities as a function of particle size and density as well as
relevant meteorological variables. It includes deposition processes. such
as, turbulent transfer, Brownian diffusion. impaction, interception, gravit
ational settling and particle rebound. Particle growth under humid conditio
ns is also considered. Sensitivity tests show that the parameterization pro
vides deposition velocities comparable with recent field observations, espe
cially for sub-micron particles. The present parameterization has also been
evaluated using two empirical bulk resistance models, which were originall
y developed from field observations. The present parameterization has been
implemented in CAM, with meteorological input provided by the Canadian Regi
onal Climate Model (RCM) to the eastern North America. A comparison of the
modelled dry deposition velocities to a variety of recent measurements that
have been reported in the literature demonstrated that the current paramet
erization produces reasonable results. The main improvement of the current
parameterization compared to earlier size-dependent particle dry deposition
models is that the current one produces more realistic deposition velociti
es for sub-micron particles and agrees better with recently published field
measurements. (C) 2000 Elsevier Science Ltd. All rights reserved.