HR: 1340h
AN: A33A-0834    [Abstracts]
TI: Aerosol dry deposition on canopies of plane obstacles
AU: * Petroff, A
EM: alexandre.petroff@ec.gc.ca
AF: Air Quality Research Division Environment Canada, 4905 Dufferin St., Toronto, on M3H 5T4, Canada
AU: Zhang, L
EM: leiming.zhang@ec.gc.ca
AF: Air Quality Research Division Environment Canada, 4905 Dufferin St., Toronto, on M3H 5T4, Canada
AB: A new model to describe aerosol transport and dry deposition on vegetative canopies has been proposed recently by Petroff et al. and applied to canopies of cylindrical obstacles such as coniferous forest (Petroff et al., 2007, Aerosol dry deposition on vegetative canopies. Part II: A new modeling approach and applications, submitted to Atmospheric Environment). In the present study, the approach is extended to canopies of plane obstacles such as grass, crop or broadleaf forest. The model takes into account the characteristics of the canopy, the aerosol and the aerodynamics. Deposition terms are modeled following an up-scaling procedure, which is based on the knowledge of collection dynamics on each individual obstacle and on the statistical distribution of these collecting elements. The statistical description applies to geometrical properties such as leaf characteristic length and orientation. Deposition mechanisms considered in this model include Brownian diffusion, interception, inertial impaction, turbulent impaction and gravitational settling. For interception, no adequate parameterisation is available in the literature to describe the collection on individual obstacle. Thus, an original parameterisation is derived for plane obstacle and is based on potential flow theory. Aerosol transport is described in a mono-dimensional configuration and neutral stratification of the atmosphere is assumed. Preliminary results indicate that the present model agrees with existing measurements data obtained both in wind-tunnel and on site.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 3379 Turbulence (4490)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting