Verification of a mathematical model for aerosol nitrate and nitric acid formation and its use for control measure evaluation

Examination of emission control alternatives shows that reduction in NOx emissions yields a nearly proportional decrease in total inorganic nitrate levels (HNO3 + aerosol nitrates). Reduction in NH3 emissions suppresses aerosol nitrate formation, resulting in higher HNO3 levels. Control of organic species emissions by the amounts expected in Los Angeles in future years causes a partial shift away from PAN formation toward greater production of HNO3. Emission control strategies can be formulated that include a combination of controls on NOx organic gases and NH3 emissions that will achieve a greater reduction in HNO3, aerosol nitrate and O3 levels than a strategy predicated on control of only a single precursor species.