The aerosol project: Introduction and some background information.

This paper provides an introduction to a series of publications in this issue of Atmospheric Environment, all summarising the results of the 'Aerosol project'. The aim of this project was (i) to quantify the contribution of acidifying aerosols to the total acid input in nature areas, (ii) to determine the contribution of aerosol deposition and canopy exchange to differences observed between atmospheric deposition and throughfall fluxes, and (iii) to determine the contribution of base cation deposition to the nutrient cycle in nature areas. Here what is done is summarised.