Dry Deposition Flux Measurements of Nanometer-Size Particles Using the Relaxed Eddy Accumulation Technique

摘要

More information on aerosol particle fluxes is necessary both to provide further tests of dry deposition models and to provide a better understanding of the formation and evolution of aerosol particles, especially for particles below 100 nm in diameter, where the impacts on atmospheric pollution and public health are substantial. In addition, the deposition velocity depends on the particle size, atmospheric stability and turbulence (Petroff et al., 2008). There is little information on the deposition velocity values for particles less than 100 nm in diameter. This study describes a prototype system based on a relaxed eddy accumulation (REA) technique to measure the dry deposition fluxes of nanometer-size aerosol particles using unattached radon (222Rn) decay products (unRnDP) as a tracer. Performance tests are carried out in the laboratory experiment. The field experiments show preliminary results of diurnal fluxes of nanometer-size aerosol particles above pasture surfaces.