MODELING THE FORMATION OF H2SO4-H2O PARTICLES IN RURAL, URBAN AND MARINE CONDITIONS

The factors which affect the formation of new sulphuric acid particles in different atmospheric conditions are investigated. An atmospheric chemistry gas phase box model coupled to a three mode integral aerosol dynamics model is used. The simulations show the dependence of the co ncentration of nucleation mode particles on initial pre-existing parti cles, the intensity of UV radiation, the emissions of dimethylsulphide (DMS) and the ratio of emissions of hydrocarbons (HC) and NOx present in the atmosphere. Eight different basic cases are simulated in urban , rural and marine conditions. The effects of pre-existing particles a s a sink of sulphuric acid are clearly seen. The increased UV radiatio n is also seen to enhance particle formation via sulphuric acid route significantly. (C) 1998 Elsevier Science B.V.