Sulfate and nitrate data from the California Aerosol Characterization Experiment (ACHEX)

Appel, B.R.; Kothny, Evaldo L.; Hoffer, Emanuel M.; Hidy, George M.; Wesolowski, J.J.

doi:10.1021/es60140a005

Cited by 102 publications

(34 citation statements)

References 12 publications

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“…The fine particle fraction will be assumed to have been formed by gas to particle conversion processes, and would contain all of the ammonium, all of the sulfate and that portion of the nitrate not attributed to the coarse particle mode. This framework for the size-segregated internal mixture hypothesis is consistent with observations that sulfate and ammonium are found chiefly in the small particle size ranges; sodium, calcium and chloride are found in large particles, while nitrate is found in significant amounts in both the coarse and fine fractions (Appel et al, 1978;Kadowaki, 1977 …”

Section: Equilibrium Calculationssupporting

confidence: 88%

Ammonia and Nitric Acid Concentrations in Equilibrium With Atmospheric Aerosols: Experiment vs Theory

HILDEMANN¹,

RUSSELL²,

CASS³

1984

CACGP Symposium on Tropospheric Chemistry With Emphasis on Sulphur and Nitrogen Cycles and the Chemistry of Clouds and Precipit

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The equilibrium between gaseous ammonia, nitric acid, and aerosol nitrate is discussed on the basis of a recent field experiment in Southern California.Comparison is drawn between theoretical equilibrium calculations and simultaneous measurements of nitric acid, ammonia, ammonium ion, nitrate ion, sulfate ion, other ionic species, temperature and dewpoint. Particulate .and gaseous pollutant concentrations at some inland sampling sites are readily explained if the aerosol is assumed to exist as an external mixture with all particulate nitrate and ammonium available to form pure NR 4 No 3 • At other monitoring sites, especially near the coast, aerosol nitrate is found in the presence of NR 3 and RN0 3 concentrations that thermodynamic calculations show are too low to produce pure NR 4 No 3 • This can be explained when the amount of aerosol nitrate that can be derived from reaction of nitric acid with sea salt and soil dust is taken into account. A calculation approach that accounts for the presence of mixed sulfate and nitrate salts improves the agreement between predicted and observed pollutant concentrations in the majority of cases studied. Uncertainties in these calculations arise from a number of sources including the thermodynamic quantities, and the effect of these uncertainties on the comparison between theory and experiment is discussed.

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Section: Equilibrium Calculationssupporting

confidence: 88%

Ammonia and Nitric Acid Concentrations in Equilibrium With Atmospheric Aerosols: Experiment vs Theory

HILDEMANN¹,

RUSSELL²,

CASS³

1984

CACGP Symposium on Tropospheric Chemistry With Emphasis on Sulphur and Nitrogen Cycles and the Chemistry of Clouds and Precipit

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“…Based on previous descriptions of aerosol nitrate concentrations in the Los Angeles area (Appel et al, 1978), high aerosol nitrate concentrations were expected in the Riverside area in the late afternoon due to production of nitric acid in the plume downwind of metropolitan Los Angeles. High aerosol nitrate levels (above 25 ~g m-3 ) were observed at Rubidoux as expected, as is seen in Figure 3a.…”

Section: Resultsmentioning

confidence: 93%

Acquisition of regional air quality model validation data for nitrate, sulfate, ammonium ion and their precursors

Russell

Cass

1984

Atmospheric Environment (1967)

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An intensive field study was conducted throughout California's South Coast Air Basin to acquire air quality model validation data for use with aerosol nitrate formation models. Aerosol nitrate, sulfate, ammonium, other major ionic aerosol species, nitric acid gas and ammonia were measured concurrently at ten sites for forty-eight consecutive hours during the period August [30][31] 1982. Ozone, NO and NO were measured at all locations, and PAN was measured at Pasadena an~ Riverside, completing a nitrogen balance on the air masses studied.The product of the meas~red nitric acid and ammon~a concentrations ranged from less than 1 ppbv to greater than 300 ppbv during the experiment, providing a wide range of conditions over which comparisons can be drawn between chemical equilibrium calculations and experimental results. The ionic material in the aerosol phase was chemically more complex than is assumed by present theoretical models for the equilibrium between NH 3 , HNOa and the aerosol phase, and included . .f. f N + ++ ++ + d Cl-. dd . . NH+ s1gn1 1cant amounts o a , a , Mg , K an 1n a 1t1on to 4 , so4 and NO)· Results of the experiment showed that aerosol nitrate levels in excess of 20 ~g m-3 accumulated in near-coastal locations in the morning of August 31, followed by subsequent transport across the air basin. Trajectory analysis showed that the afternoon aerosol nitrate peak observed inland at Rubidoux near Riverside was associated with the same air mass that contained the high morning nitrate levels near the coast, indicating that description of both transport and atmospheric chemical reactions is important in understanding regional nitrate dynamics. + Mechanical Engineering Department and Environmental Quality Laboratory * Environmental Engineering Science Department and EnvironmentalQuality Laboratory IntroductionAmmonia and nitric acid vapor react to form ammonium nitrate aerosol. This is important because ammonium nitrate containing aerosols account for a significant fraction of local and regional visibility problems, particularly in Los Angeles and Denver (White and Roberts, 1977;Cass, 1979;Groblicki et al., 1981 Environmental Protection Agency (1973, 1978 et seq.). PAN was measured by electron capture gas chromatography, and NO and N0 2 were measured by chemiluminescence by researchers at the University of California at Riverside (UCR). PAN also was measured by the same principle at Caltech in Pasadena.The aerosol, nitric acid and ammonia sampling apparatus for this experiment is shown schematically in Figure 2. Aerosol nitrate and nitric acid concentrations were measured both by dual filter methods and by the denuder difference method. Gaseous ammonia was measured by a dual filter method using oxalic acid impregnated filters as a sink for NH 3 • Filter holders were of open-faced design so that any large particle nitrates would be collected. The sampling apparatus was surrounded by a bug screen and shaded by a sun shield to prevent nitrate volatilization through over-heating. Nine of the ten sa...

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“…NO 3 and SO 4 mass median diameters were obtained from particle size distributions specific to Los Angeles. 19,20 BETACALC and FRACTION require deposition and settling velocity estimates and, thus, MMD estimates for any species not measured in the source profile. A MMD of 0.5 m was assumed for unknown species in the fine fraction.…”

Section: Methods For Including Differential Deposition Inmentioning

confidence: 99%

Chemical Mass Balance Model with Fractionation for Apportioning PM_2.5: A Test Case for Los Angeles Traffic Sources

Sattler

Liljestrand

2005

Journal of the Air & Waste Management Association

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Chemical mass balance receptor models (CMBs) use measured pollutant concentrations, along with source information, to apportion the contributions of primary sources to the measured concentrations. CMBs can be used to evaluate the accuracy of the emission inventories that underlie State Implementation Plan (SIP) modeling, by providing an allocation of emissions to individual source categories. CMBs, however, traditionally have not accounted for the chemical reaction and differential deposition or fractionation that occur between the source and receptor. This means that they have historically had severe limitations in apportioning secondary particulate matter (PM), which is an especially important component of fine PM (PM 2.5 ). Stafford and Liljestrand developed a method to account for fractionation in CMBs using depletion factors based on a solution of the steady-state advection-dispersion equation, including gravitational settling, dry deposition, and first-order chemical reaction.

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Sulfate and nitrate data from the California Aerosol Characterization Experiment (ACHEX)

Cited by 102 publications

References 12 publications

Ammonia and Nitric Acid Concentrations in Equilibrium With Atmospheric Aerosols: Experiment vs Theory

Ammonia and Nitric Acid Concentrations in Equilibrium With Atmospheric Aerosols: Experiment vs Theory

Acquisition of regional air quality model validation data for nitrate, sulfate, ammonium ion and their precursors

Chemical Mass Balance Model with Fractionation for Apportioning PM_2.5: A Test Case for Los Angeles Traffic Sources

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Sulfate and nitrate data from the California Aerosol Characterization Experiment (ACHEX)

Cited by 102 publications

References 12 publications

Ammonia and Nitric Acid Concentrations in Equilibrium With Atmospheric Aerosols: Experiment vs Theory

Ammonia and Nitric Acid Concentrations in Equilibrium With Atmospheric Aerosols: Experiment vs Theory

Acquisition of regional air quality model validation data for nitrate, sulfate, ammonium ion and their precursors

Chemical Mass Balance Model with Fractionation for Apportioning PM2.5: A Test Case for Los Angeles Traffic Sources

Contact Info

Product

Resources

About

Chemical Mass Balance Model with Fractionation for Apportioning PM_2.5: A Test Case for Los Angeles Traffic Sources