DRY DEPOSITION OF FINE AEROSOL TO A SHORT GRASS SURFACE

Soluble sulphate has been used as a marker for fine aerosols and dry deposition has been estimated using a profile technique. The effects of coarse particles were excluded from the measurements by passage of the sampled air through Nuclepore polycarbonate prefilters, resulting in a 2-mu-m upper cut-off. A total of 99 separate experiments were conducted between June 1988 and June 1989 and 50 acceptable profiles remained after the application of a rigorous quality control procedure. The mean deposition velocity was found to be equal to 0.1 +/- 0.03 (standard error) cm s-1. There were no observed dependences of deposition velocity on either atmospheric stability or friction velocity within the range of conditions encountered.