Measurements of Carbonaceous Aerosols Using Semi-Continuous Thermal-Optical Method

Yu, Xiao‐Ying

doi:10.5772/16413

Cited by 4 publications

(3 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As the correlation between thermal and optical EC was observed to be rather good in previous SCCA validation work (Arhami et al, 2006;Yu, 2011), it provided another criteria to testify the validity of the suggested correction method. Since the TC underestimation existed nearly all the time for IMPshort, this protocol was not considered here.…”

Section: Reduction and Correction Methodsmentioning

confidence: 81%

A newly identified calculation discrepancy of the Sunset semi-continuous carbon analyzer

Zheng

Cheng

et al. 2014

Atmos. Meas. Tech.

View full text Add to dashboard Cite

Abstract. The Sunset semi-continuous carbon analyzer (SCCA) is an instrument widely used for carbonaceous aerosol measurement. Despite previous validation work, in this study we identified a new type of SCCA calculation discrepancy caused by the default multipoint baseline correction method. When exceeding a certain threshold carbon load, multipoint correction could cause significant total carbon (TC) underestimation. This calculation discrepancy was characterized for both sucrose and ambient samples, with two protocols based on IMPROVE (Interagency Monitoring of PROtected Visual Environments) (i.e., IMPshort and IMPlong) and one NIOSH (National Institute for Occupational Safety and Health)-like protocol (rtNIOSH). For ambient samples, the IMPshort, IMPlong and rtNIOSH protocol underestimated 22, 36 and 12% of TC, respectively, with the corresponding threshold being ~ 0, 20 and 25 μgC. For sucrose, however, such discrepancy was observed only with the IMPshort protocol, indicating the need of more refractory SCCA calibration substance. Although the calculation discrepancy could be largely reduced by the single-point baseline correction method, the instrumental blanks of single-point method were higher. The correction method proposed was to use multipoint-corrected data when below the determined threshold, and use single-point results when beyond that threshold. The effectiveness of this correction method was supported by correlation with optical data.

show abstract

Section: Reduction and Correction Methodsmentioning

confidence: 81%

A newly identified calculation discrepancy of the Sunset semi-continuous carbon analyzer

Zheng

Cheng

et al. 2014

Atmos. Meas. Tech.

View full text Add to dashboard Cite

show abstract

“…Numerous studies have been performed to investigate the POA / POC and SOA / SOC ratios (Aiken et al, 2008;Yu et al, 2009;Yu, 2011), which can be used to obtain OA concentrations from measured EC and OC concentrations. In this study, the POC / EC, POA / POC, and SOA / SOC ratios are assumed to be 2.4, 1.2, and 1.6, respectively, based on the previous studies (Cao et al, 2007;Aiken et al, 2008;Yu et al, 2009;Yu, 2011). It is worth to note that these assumed values might affect the model-measurement comparisons.…”

Section: Measurement Datamentioning

confidence: 99%

Simulations of organic aerosol concentrations during springtime in the Guanzhong Basin, China

Feng

Cao

et al. 2016

Atmos. Chem. Phys.

View full text Add to dashboard Cite

Abstract. The organic aerosol (OA) concentration is simulated in the Guanzhong Basin, China from 23 to 25 April 2013 utilizing the WRF-CHEM model. Two approaches are used to predict OA concentrations: (1) a traditional secondary organic aerosol (SOA) module; (2) a non-traditional SOA module including the volatility basis-set modeling method in which primary organic aerosol (POA) is assumed to be semivolatile and photochemically reactive. Generally, the spatial patterns and temporal variations of the calculated hourly near-surface ozone and fine particle matters agree well with the observations in Xi'an and surrounding areas. The model also yields reasonable distributions of daily PM 2.5 and elemental carbon (EC) compared to the filter measurements at 29 sites in the basin. Filter-measured organic carbon (OC) and EC are used to evaluate OA, POA, and SOA using the OC / EC ratio approach. Compared with the traditional SOA module, the non-traditional module significantly improves SOA simulations and explains about 88 % of the observed SOA concentration. Oxidation and partitioning of POA treated as semivolatile constitute the most important pathway for the SOA formation, contributing more than 75 % of the SOA concentrations in the basin. Residential emissions are the dominant anthropogenic OA source, constituting about 50 % of OA concentrations in urban and rural areas and 30 % in the background area. The OA contribution from transportation emissions decreases from 25 % in urban areas to 20 % in the background area, and the industry emission OA contribution is less than 6 %.

show abstract

“…So assumptions inherent to this method would introduce uncertainties in the estimation of SOC (Yu, 2011).…”

Section: B) Carbonaceous Materialsmentioning

confidence: 99%

Chemical Composition of PM2.5 and its Impact on Visibility in Guangzhou, Southern China

Wang

Zhou

Cohen

et al. 2016

Aerosol Air Qual. Res.

View full text Add to dashboard Cite

A one-year field experiment was conducted in 2013 at an urban and suburban site in Guangzhou, Southern China to study the chemical compositions of PM 2.5 and reconstruct the IMPROVE Algorithm to investigate the impact of aerosol components on visibility. Annual average PM 2.5 mass concentration was 61.3 ± 27.6 and 54.2 ± 29.7 µg m -3 at the urban and suburban site, with organic matter (OM), sulfate (SO 4 2-), and nitrate (NO 3 -) among the dominant components, accounting for 40.3%, 16.3%, and 8.0% of the PM 2.5 mass concentration respectively. Based on the modified IMPROVE Algorithm, the localized Mass Scattering Efficiencies (MSE) for sulfate and nitrate was obtained, with values of 2.16 ± 0.34 m 2 g -1 and 2.63 ± 0.66 m 2 g -1 at urban site and 2.22 ± 0.31 m 2 g -1 and 2.76 ± 0.84 m 2 g -1 at suburban site. Hygroscopic growth factors (G f ) for OM and EC were also taken into consideration with average values of 1.28 ± 0.13 m 2 g -1 and 1.15 ± 0.11 m 2 g -1 at the urban site and 1.18 ± 0.09 m 2 g -1 and 1.10 ± 0.09 m 2 g -1 at the suburban site. The estimated total light extinction coefficient was 294.7 ± 106.9 and 255.8 ± 119.0 Mm -1 at the urban and suburban site, with OM, SO 4 2-and NO 3 -contributing 41.7%, 16.5% and 11.5% at the urban site, and 42.1%, 21.3% and 9.1% at the suburban site. Secondary water-soluble ions and OM as a whole was becoming increasingly vital under polluted conditions, with nitrate in particular being more important under heavily polluted conditions in Guangzhou.

show abstract

Measurements of Carbonaceous Aerosols Using Semi-Continuous Thermal-Optical Method

Cited by 4 publications

References 62 publications

A newly identified calculation discrepancy of the Sunset semi-continuous carbon analyzer

A newly identified calculation discrepancy of the Sunset semi-continuous carbon analyzer

Simulations of organic aerosol concentrations during springtime in the Guanzhong Basin, China

Chemical Composition of PM2.5 and its Impact on Visibility in Guangzhou, Southern China

Contact Info

Product

Resources

About