Spatial and Temporal Distribution of Atmospheric Nitric Acid and Particulate Nitrate Concentrations in the Los Angeles Area

摘要: A 1-year atmospheric measurement program was conducted throughout the South Coast Air Basin in the greater Los Angeles area during 1986 to determine the long-term average concentration patterns of gaseous HNO_3, and aerosol nitrates. Upwind air basin at San Nicolas Island, HNO_3, levels are very low, averaging 0.3 µg m^(-3) (0.1 ppb) over year 1986. Annual HNO_3 concentrations ranged from 3.1 (1.2 near the Southern California coast 6.9 (2.7 an inland site Gabriel Mountains. At most monitoring stations, a majority inorganic nitrate (HNO_3 plus its reaction product, nitrate) aerosol phase. Conversion HNO_3 nitrates most pronounced Rubidoux, Riverside, CA, where on the average 94% found the aerosol phase, and fine particle concentrations exceeded 109 pg µg^(-3), peak 24-h period examined.