Simultaneous nitric acid, particulate nitrate and acidity measurements in ambient air

PM10and PM2.5Compositions in California's San Joaquin Valley

“…The nitrate concentrations in this study were often double that of sulfate. The high nitrate concentrations were well above any contribution from the known biases in the nitrate measurement methods (e.g., Appel et al, 1980Appel et al, , 1981Forrest et al, 1980). Tracer (SF,) releases during winter showed that 50% of the tracer gas remained in the SJV 60 hours after its release.…”

Quantitative Estimation of Sodium- and Ammonium-Nitrate, Ammonium Chloride, and Ammonium Sulfate in Ambient Particulate Matter

“…24 The presence of atmospheric NH4CI has been shown. 9 -20 * 25 NH4CI in particulate matter is also considered to be one of the important volatile components. Hence, the lower and upper limits of the intercept of the regression line correspond to the lowest and highest concentration of NH 4 C1 in the ambient air samples, respectively.…”

Characterization of PM25 and PM10 in the South Coast Air Basin of Southern California: Part 2—Temporal Variations

“…High NH 4 + and NO 3 -concentrations in the fall were caused by the favorable formation of NH 4 NO 3 under cool temperatures and stagnation conditions. [5][6][7] Meteorological conditions leading to high NH 4 NO 3 concentrations in the fall are characterized in Bassett et al 8 Concentrations of SO 4 = were highest in summer and lowest in winter. During the summer months, a warm air mass, produced by subsidence on the eastern side of the semipermanant Pacific high-pressure system, frequently descends over the cool, moist marine layer.…”