The contribution of elemental carbon to the optical properties of rural atmospheric aerosols

Japar, Steven M.; Brachaczek, Wanda W.; Gorse, Robert A.; Norbeck, Joseph M.; Pierson, William R.

doi:10.1016/0004-6981(86)90163-0

Cited by 105 publications

(46 citation statements)

References 35 publications

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“…1 Black carbon has a significant impact on visibility and probably on climate, because, being black, it is the most absorbing species for sunlight in the atmosphere. 2 Because of its catalytic properties, it may be involved in important chemical reactions involving atmospheric SO 2 , NO x , O 3 , and other gaseous compounds. 3 The small particle size, large specific surface, and consequent adsorbing properties of black carbon particles make them potential transporters of toxic compounds into respiratory systems.…”

Section: Discussionmentioning

confidence: 99%

Investigation of Sources of Atmospheric Aerosol at a Hot Spot Area in Dhaka, Bangladesh

Begum

Biswas

Kim

et al. 2005

Journal of the Air & Waste Management Association

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Samples of fine and coarse fractions of airborne particulate matter were collected at the Farm Gate area in Dhaka from July 2001 to March 2002. Dhaka is a hot spot area with very high pollutant concentrations because of the proximity of major roadways. The samples were collected using a "Gent" stacked filter unit in two fractions of 0-to 2.2-m and 2.2-to 10-m sizes. The samples were analyzed for elemental concentrations by particle-induced X-ray excitation (PIXE) and for black carbon by reflectivity methods, respectively. The data were analyzed by positive matrix factorization (PMF) to identify the possible sources of atmospheric aerosols in this area. Six sources were found for both the coarse and fine PM fractions. The data sets were also analyzed by an expanded model to explore additional sources. Seven and six factors were obtained for coarse and fine PM fractions, respectively, in these analyses. The identified sources are motor vehicle, soil dust, emissions from construction activities, sea salt, biomass burning/brick kiln, resuspended/fugitive Pb, and two-stroke engines. From the expanded modeling, ϳ50% of the total PM 2.2 mass can be attributed to motor vehicles, including two-stroke engine vehicle in this hot spot in Dhaka, whereas the PMF modeling indicates that 45% of the total PM 2.2 mass is from motor vehicles. The PMF2 and expanded models could resolve ϳ4% and 3% of the total PM 2.2 mass as resuspended/fugitive Pb, respectively. Although, Pb has been eliminated from gasoline in Bangladesh since July 1999, there still may be substantial amounts of accumulated lead in the dust near roadways as well as fugitive Pb emissions from battery reclaimation and other industries. Soil dust is the largest component of the coarse particle fraction (PM 2.2-10 ) accounting for ϳ71% of the total PM 2.2-10 mass in the expanded model, whereas from the PMF modeling, the dust (undifferentiated) contribution is ϳ49%.

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Section: Discussionmentioning

confidence: 99%

Investigation of Sources of Atmospheric Aerosol at a Hot Spot Area in Dhaka, Bangladesh

Begum

Biswas

Kim

et al. 2005

Journal of the Air & Waste Management Association

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“…Particle scattering is produced by a wide range of aerosol compositions whereas particle absorption is only due to elemental carbon (EC) in the visible region (Rosen et al, 1978;Yasa et al, 1979;Japar et al, 1986;Adams et al, 1990). In urban atmospheres, fine particles are usually the main contributors to visible light extinction (Adams et al, 1990a).…”

Section: Aerosol Optical Properties and Visibilitymentioning

confidence: 99%

Particulate Air Pollution in Mexico City: A Detailed View

Vega

Eidels

Ruiz

et al. 2010

Aerosol Air Qual. Res.

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A detailed view of particulate air pollution in Mexico City resulting from several analyses of data collected during four field campaigns is given. The resulting database from the March 1997 campaign was used to identify and quantify the contribution of particles to the atmosphere from different emission sources, to estimate transport and dispersion of pollutants and to estimate the amount of secondary organic carbon. Emission inventories of PM 10 , PM 2.5 and ammonia were also calculated. Data from March 1997 and March 2002 campaigns were used to estimate aerosol optical properties and its impact on visibility, and measurements during March and November 2001 and March 2002 were used to obtain particle mass size distributions. Results showed that major contribution of PM 2.5 were the mobile source emissions with 45%. Computer simulations were run for a wind blown dust episode and results agreed with observations. Particle concentrations were found to be inversely related to transport wind speed, and the highest pollutant dispersion was in the afternoon as calculated with the ventilation index. An average of 25% of the total organic carbon in the PM 2.5 was associated to secondary organic aerosol estimated with an empirical model. Particles of sizes between 0.1 and 1.0 μm accounted for the highest mass concentrations and were associated mainly to primary emissions. The earlier visible light absorption peaks that appeared in the diurnal patterns were attributed to the elevated elemental carbon vehicular emissions during the heavy traffic hours while the later light scattering peaks were attributed to secondary aerosol formed photochemically in the atmosphere. Dairy and non-dairy cattle were the dominant sources according to the calculated emission inventory (EI) for ammonia. PM 2.5 mobile sources derived from the EI were 11% whereas those estimated with the receptor model were 45%.

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“…These species influence air quality, human health, and climate change (e.g., Japar et al, 1986;Dockery et al, 1992;Novakov and Penner, 1993;Cheng and Tsai, 2000;Satheesh and Moorthy, 2005;Viana et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

“…It is a measure of the relative effectiveness of light absorption by EC. The b asp is usually determined by Aethalometers or by Particle Soot Absorption Photometers (PSAP), whereas the EC is measured by a thermal or thermal/optical method (Jennings and Pinnick, 1980;Japar et al, 1986;Sharma et al, 2002). Estimates of the SAC, based on absorption measured with Aethalometers or Particle Soot Absorption Photometers (PSAP), vary from 2 to 55 m 2 g −1 (Liousse et al, 1993;Snyder and Schauer, 2007).…”

Section: Introductionmentioning

confidence: 99%

Observations of OM/OC and specific attenuation coefficients (SAC) in ambient fine PM at a rural site in central Ontario, Canada

et al. 2010

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Abstract. Ambient particulate matter (PM) samples were collected on quartz filters at a rural site in central Ontario during an intensive study in 2007. The concentrations of organic carbon (OC), pyrolysis organic carbon (POC), and elemental carbon (EC) were determined by thermal analysis. The concentrations are compared to the organic aerosol mass concentration (OM) measured with an Aerodyne C-ToF Aerosol Mass Spectrometer (AMS) and to the particle absorption coefficient (b asp ) obtained from a Radiance Research Particle Soot Absorption Photometer (PSAP). The total organic mass to organic carbon ratios (OM/OC) and specific attenuation coefficients (SAC=b asp /EC) are derived. Proportionality of the POC mass with the oxygen mass in the aerosols estimated from the AMS offers a potential means to estimate OM/OC from thermal measurements only. The mean SAC for the study is 3.8±0.3 m 2 g −1 . It is found that the SAC is independent of or decrease with increasing particle mass loading, depending on whether or not the data are separated between aerosols dominated by more recent anthropogenic input and aerosols dominated by longer residence time or biogenic components. There is no evidence to support an enhancement of light absorption by the condensation of secondary material to particles, suggesting that present model simulations built on such an assumption may overestimate atmospheric warming by BC.

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The contribution of elemental carbon to the optical properties of rural atmospheric aerosols

Cited by 105 publications

References 35 publications

Investigation of Sources of Atmospheric Aerosol at a Hot Spot Area in Dhaka, Bangladesh

Investigation of Sources of Atmospheric Aerosol at a Hot Spot Area in Dhaka, Bangladesh

Particulate Air Pollution in Mexico City: A Detailed View

Observations of OM/OC and specific attenuation coefficients (SAC) in ambient fine PM at a rural site in central Ontario, Canada

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