DEPOSITION OF Pb-CONTAINING PARTICLES FROM THE LOS ANGELES ATMOSPHERE.

Particle deposition from the atmosphere in the absence of precipitation (dry deposition) is controlled by complex transport processes. Most previous work in this area has been confined to laboratory experiments, although some field work has been reported. The particle deposition rate determines the residence time of particles in an urban atmosphere and provides information on the effects of a source on surrounding regions. The deposition rate depends on the properties of the aerosol, the air flow patterns, and the nature of the deposition surface. The paper deals with deposition by examining airborne size distributions and fluxes to flat, horizontal surfaces. From the airborne size distribution, the deposition rates can be predicted and compared with the flux determined experimentally.