Author(s)

P. Muthusubramanian, F. De Santis & I. Allegrini

Abstract

Air moving into the open end of a passive sampler affects the pollutant mass transfer by generating eddies leading to a reduction in the molecular diffusion length and a consequent overestimation of the pollutant concentration. This decrease is found to be experimentaly in the range of 10-40 % depending on the wind speed at the site. Assuming that the eddy turbulence is isotropic and the horizontal wind velocity u can be time averaged, an exponential equation has been derived connecting the decrease of molecular diffusion length 1 with u through the surface roughness length ZQ, the average friction ve

Keywords