Chemical Composition of Pasadena Aerosol by Particle Size and Time of Day

Mueller, Peter; Mosley, R.W.; Pierce, Leah

doi:10.1016/b978-0-12-347250-2.50029-x

Cited by 10 publications

(2 citation statements)

References 4 publications

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“…The ion balance closes closely in spite of the fact that co;, OR-and H+ concentrations were not measured. Previous studies in the SCAB show the presence of very low carbonate carbon levels in the aerosol (Mueller et al, 1972). Large amounts of hydrogen ion would not be expected because of the great excess of ammonia present during this experiment.…”

Section: Trajectory Analysis Shows That the Peak Nitrate Concentratiomentioning

confidence: 96%

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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Section: Trajectory Analysis Shows That the Peak Nitrate Concentratiomentioning

confidence: 96%

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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“…In surveys of sites in the United States it has been observed that EC comprises from 1 to 13%, and from 2 to 9% of the mass concentration of atmospheric aerosol from rural and urban locations, respectively [ Shah et al , 1986; Malm et al , 1994]. CC is present in mineral dusts; in most urban situations CC is a minor component of particles of diameters less than 2.5 μm (PM 2.5 ); CC comprising less than 1.4% of the mass of Pasadena PM 2.5 [ Mueller et al , 1972].…”

Section: Introductionmentioning

confidence: 99%

Airborne measurements of atmospheric carbonaceous aerosols during ACE‐Asia

2002

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[1] Airborne levels of carbonaceous aerosols were measured using the Twin Otter aircraft during the Aerosol Characterization Experiment (ACE)-Asia. Particles were collected using a newly developed honeycomb denuder sampler and organic carbon (OC), elemental carbon (EC), and carbonate (CC) carbon levels determined using a thermal-optical carbon analyzer. During some flights, atmospheric layers could be identified as marine boundary, pollution dominated, or mineral dust dominated. Å ngstrom exponent (å) values, calculated based on data from an onboard three-wavelength nephelometer, were used to discern the nature of some individual layers. Values of å for individual layers ranged from 0.2 to 2, corresponding to dust-and pollution-dominated layers, respectively. OC and EC concentrations below 3 km ranged from 0.58 to 29 mg C m À3 and from 0.20 to 1.8 mg C m À3 , respectively. In general, for a given type of atmospheric layer, higher levels of total carbon (TC) were observed during ACE-Asia than those observed during ACE-2, Tropospheric Aerosol Radiative Forcing Observational Experiment (TARFOX) and Indian Ocean Experiment (INDOEX). Mixed layers of dust and pollution were found on some occasions. CC was detected in samples taken from layers in which å = 1.6, indicating that significant amounts of dust can be present even though å > 0.2. A linear regression of light absorption coefficient s ap (Mm À1 ) versus EC concentration had an r 2 of only 0.50, indicating that parameters other than the mass of EC significantly affected the value of s ap . The mass absorption coefficient E abs (m 2 g À1 ) varied by as much as a factor of 8 between sampling events, and the average value of 11 m 2 g À1 (±5.0) agrees well with previous published values.

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Route-based chemical significance and source origin of marine PM2.5 at three remote islands in East Asia: Spatiotemporal variation and long-range transport

Yuan

Hung

et al. 2023

Atmospheric Pollution Research

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Chemical Composition of Pasadena Aerosol by Particle Size and Time of Day

Cited by 10 publications

References 4 publications

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

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

Airborne measurements of atmospheric carbonaceous aerosols during ACE‐Asia

Route-based chemical significance and source origin of marine PM2.5 at three remote islands in East Asia: Spatiotemporal variation and long-range transport

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