Title
Comparison of SOC estimates and uncertainties from aerosol chemical composition and gas phase data in Atlanta
DOI
https://doi.org/10.1016/j.atmosenv.20https://doi.org/10.07.017
Document Type
Article
Publication Date
10-1-2010
Publication Title
Atmospheric Environment
Abstract
In the Southeastern US, organic carbon (OC) comprises about 30% of the PM mass. A large fraction of OC is estimated to be of secondary origin. Long-term estimates of SOC and uncertainties are necessary in the evaluation of air quality policy effectiveness and epidemiologic studies. Four methods to estimate secondary organic carbon (SOC) and respective uncertainties are compared utilizing PM chemical composition and gas phase data available in Atlanta from 1999 to 2007. The elemental carbon (EC) tracer and the regression methods, which rely on the use of tracer species of primary and secondary OC formation, provided intermediate estimates of SOC as 30% of OC. The other two methods, chemical mass balance (CMB) and positive matrix factorization (PMF) solve mass balance equations to estimate primary and secondary fractions based on source profiles and statistically-derived common factors, respectively. CMB had the highest estimate of SOC (46% of OC) while PMF led to the lowest (26% of OC). The comparison of SOC uncertainties, estimated based on propagation of errors, led to the regression method having the lowest uncertainty among the four methods. We compared the estimates with the water soluble fraction of the OC, which has been suggested as a surrogate of SOC when biomass burning is negligible, and found a similar trend with SOC estimates from the regression method. The regression method also showed the strongest correlation with daily SOC estimates from CMB using molecular markers. The regression method shows advantages over the other methods in the calculation of a long-term series of SOC estimates. © 2010 Elsevier Ltd. 2.5 2.5
Volume
44
Issue
32
First Page
3907
Last Page
3914
ISSN
13522310
Recommended Citation
Pachon, Jorge E.; Balachandran, Sivaraman; Hu, Yongtao; Weber, Rodney J.; Mulholland, James A.; and Russell, Armistead G., "Comparison of SOC estimates and uncertainties from aerosol chemical composition and gas phase data in Atlanta" (2010). Scopus Unisalle. 645.
https://ciencia.lasalle.edu.co/scopus_unisalle/645
Identifier
SCOPUS_ID:77955922326