A characterization of the principal PM-10 species in Claremont (summer) and Long Beach (fall) during SCAQS

Wolff, George T.; Ruthkosky, Martin S.; Stroup, David P.; Korsog, Patricia E.

doi:10.1016/0960-1686(91)90093-m

Cited by 40 publications

(19 citation statements)

References 22 publications

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“…Estimates of the POM mass concentration from measurements of its C content have extensively been obtained using molecular‐to‐carbon ratios ranging from 1.2 to 1.7 [e.g. Gray et al , 1986; Wolff et al , 1991; Malm et al , 1994; Eatough et al , 1996; Hegg et al , 1997]. Following Eatough et al [1996], we calculated POM concentrations by multiplying the measured particulate organic carbon (POC) concentration with a constant factor or 1.4.…”

Section: Experimental Methodsmentioning

confidence: 99%

Submicron aerosol mass balance at urban and semirural sites in the Milan area (Italy)

Putaud¹

2002

J.‐Geophys.‐Res.

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[1] During the Pianura Padana Produzione di Ozono (PIPAPO) field campaign (May-June 1998), aerosol measurements were performed at an urban site and a semirural site to determine the particulate matter chemical composition in the Milan area. Aerosol samples were collected on filters for subsequent chemical analysis using virtual impactors. Possible sampling artifacts for semivolatile particulate species were addressed. Our NH 4 NO 3 measurements were successfully compared with artifact free wet denuder-wet aerosol collector sampler data. Positive sampling artifacts for organic species were corrected using the back-to-back filter technique, allowing us to assess the lower limit for particulate organic carbon (POC) concentrations. Aerosol size distributions were measured on-line with differential mobility analyzers (DMA). The variations in the submicron aerosol mass concentration estimated from chemical analyses compared well with the variations in the submicron particle volume calculated from number size distributions. At both sites, 70% of the PM10 mass was found in the submicron fraction. , respectively. At the semi-rural site, these concentrations were 4.9 mg m À3 , 4.0 mg m À3 , and 5.6 mgC m À3, respectively. These results show that sulfate and nitrate contribute about the same amount to submicron aerosol mass concentration, and that particulate organic matter (POM) could be the major component of the aerosol submicron mass in the Milan region, especially in semirural areas. The correlation between normalized concentrations of POM and O 3 observed at the semirural site suggests that POM results at least partly from photochemical oxidation of volatile organic compounds (VOC). It is likely that reducing anthropogenic VOC emissions would lead to lower POC and total submicron aerosol concentrations in semirural areas around Milan.

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Section: Experimental Methodsmentioning

confidence: 99%

Submicron aerosol mass balance at urban and semirural sites in the Milan area (Italy)

Putaud¹

2002

J.‐Geophys.‐Res.

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“…A fraction of the organic mass, equal to the ratio of PILS WSOC to AMS organic mass, is assumed soluble with a molar volume of = 1.48 × 10 −4 m 3 mol −1 , effective van't Hoff factor of ν = 1, and 10% surface tension depression with respect to pure water. In this study, the WSOC/OC is converted to WSOC/OM by a factor of 1.5 [ Wolff et al , 1991; Seinfeld and Pandis , 2006]. For aerosol containing mostly OOA, this value may be higher (∼1.8 to 2.1 [ Turpin and Lim , 2001; Aiken et al , 2008]).…”

Section: Data Analysis and Ccn Predictionmentioning

confidence: 99%

Airborne cloud condensation nuclei measurements during the 2006 Texas Air Quality Study

et al. 2011

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[1] Airborne measurements of aerosol and cloud condensation nuclei (CCN) were conducted aboard the National Oceanic and Atmospheric Administration WP-3D platform during the 2006 Texas Air Quality Study/Gulf of Mexico Atmospheric Composition and Climate Study (TexAQS/GoMACCS). The measurements were conducted in regions influenced by industrial and urban sources. Observations show significant local variability of CCN activity (CCN/CN from 0.1 to 0.5 at s = 0.43%), while variability is less significant across regional scales (∼100 km × 100 km; CCN/CN is ∼0.1 at s = 0.43%). CCN activity can increase with increasing plume age and oxygenated organic fraction. CCN measurements are compared to predictions for a number of mixing state and composition assumptions. Mixing state assumptions that assumed internally mixed aerosol predict CCN concentrations well. Assuming organics are as hygroscopic as ammonium sulfate consistently overpredicted CCN concentrations. On average, the water-soluble organic carbon (WSOC) fraction is 60 ± 14% of the organic aerosol. We show that CCN closure can be significantly improved by incorporating knowledge of the WSOC fraction with a prescribed organic hygroscopicity parameter ( = 0.16 or effective ∼ 0.3). This implies that the hygroscopicity of organic mass is primarily a function of the WSOC fraction. The overall aerosol hygroscopicity parameter varies between 0.08 and 0.88. Furthermore, droplet activation kinetics are variable and 60% of particles are smaller than the size characteristic of rapid droplet growth.

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“…The Los Angeles metropolitan area is an exception, for it has been studied extensively. [11][12][13][14][15] During three 1-year periods since 1982, fine particle concentration and complete chemical speciation have been measured by our research group in Southern California. To date, only the 1982 data and a fraction of the 1993 data have been published.…”

Section: Introductionmentioning

confidence: 99%

Trends in Fine Particle Concentration and Chemical Composition in Southern California

Christoforou

Salmon

Hannigan

et al. 2000

Journal of the Air & Waste Management Association

119

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Airborne fine particle mass concentrations in Southern California have declined in recent years. Trends in sulfate and elemental carbon (EC) particle concentrations over the period 1982-1993 are consistent with this overall improvement in air quality and help to confirm some of the reasons for the changes that are seen. Fine particle sulfate concentrations have declined as a strict sulfur oxides (SOx) emission control program adopted in 1978 was implemented over time. Fine particle elemental (black) carbon concentrations have declined over a period when newer diesel engines and improved diesel fuels have been introduced into the vehicle fleet. Organic aerosol concentrations have not declined as rapidly as the EC particle concentrations, despite the fact that catalyst-equipped cars having lower particle emission rates were introduced into the vehicle fleet alongside the diesel engine improvements mentioned above. This situation is consistent with the growth in population and vehicle miles traveled in the air basin over time. Fine particle ammonium nitrate in the Los Angeles area atmosphere contributes more than half of the fine aerosol mass concentration on the highest concentration days of the year, emphasizing both the need for accurate aerosol nitrate measurements and the likely importance of deliberate control of aerosol nitrate as a part of any serious further fine particle control program for the Los Angeles area.

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A characterization of the principal PM-10 species in Claremont (summer) and Long Beach (fall) during SCAQS

Cited by 40 publications

References 22 publications

Submicron aerosol mass balance at urban and semirural sites in the Milan area (Italy)

Submicron aerosol mass balance at urban and semirural sites in the Milan area (Italy)

Airborne cloud condensation nuclei measurements during the 2006 Texas Air Quality Study

Trends in Fine Particle Concentration and Chemical Composition in Southern California

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