An analytical model for the altitude variation of aerosol number densitiesin the coastal atmospheric boundary layer

A simplified one dimensional analytical model to describe the altitude Vari ation of aerosol number densities in the atmospheric boundary layer during clear sky and calm/moderate wind conditions, over a plane terrain on the tr opical seacoast, is developed. The analytical model is mainly defined by tw o parameters, the aerosol mixing height and the exponential rate of decreas e above the mixing height. The effect of surface impaction is also taken in to account in this model. It is seen that this parameter varies with season . By matching the analytical profile with the observed mean profile in each month, the surface source strength has been estimated. The seasonal and in ter-annual variations of this parameter are studied. (C) 1999 Elsevier Scie nce Ltd. All rights reserved.