RESPONSE OF INORGANIC PM TO PRECURSOR CONCENTRATIONS

An inorganic aerosol equilibrium model is used to investigate the resp onse of inorganic particulate matter (PM) concentrations with respect to the precursor concentrations of sulfuric acid, ammonia, and nitric acid over a range of temperatures and relative humidities. Diagrams sh owing regions of PM response to precursor concentrations are generated ,thus allowing the qualification of assumptions concerning the respons e of PM to sulfate and overall sensitivity to ammonia and nitric acid availability. The PM concentration level responds nonlinearly to sulfa te and shows overall sensitivity to ammonia and nitric acid availabili ty for specific atmospheric conditions and precursor concentrations. T he generated diagrams are applied as a means of approximating the PM r esponse to precursor concentrations for two urban polluted areas. In b oth cases, reductions in ammonia emissions have the most significant i mpact on the total PM level. However, such a reduction will result in significant increases in atmospheric acidity.