scholarly journals Water-soluble organic carbon aerosols during a full New Delhi winter: Isotope-based source apportionment and optical properties

2014 ◽  
Vol 119 (6) ◽  
pp. 3476-3485 ◽  
Author(s):  
Elena N. Kirillova ◽  
August Andersson ◽  
Suresh Tiwari ◽  
Atul Kumar Srivastava ◽  
Deewan Singh Bisht ◽  
...  
2017 ◽  
Author(s):  
Heejun Han ◽  
Guebuem Kim

Abstract. Atmospheric humic-like substance (HULIS) is an important fraction of water-soluble organic carbon (WSOC) accounting for the light-absorbing properties of organic aerosols. HULIS is responsible for light-absorbing properties of organic aerosols in the atmosphere. Although various sources of HULIS have been studied extensively, its sinks are poorly constrained. In this study, we found seasonal changes in the optical and chemical characteristics of HULIS and WSOC, which are decreased by approximately 80 % and 30 %, respectively, from the cold season (Oct–Jan) to the warm season (Jun–Sep) due to enhanced solar ultraviolet (UV) radiation. The dominant role of photochemical degradation on light-absorbing organic aerosols, as a sink of HULIS, was further confirmed based on a laboratory experiment by evaluating impact of UV radiation on the optical properties of HULIS and WSOC contents. Our results suggest that seasonal variation of HULIS in WSOC is resulted mainly by photo-induced degradation in the atmosphere. Thus, photochemical degradation of HULIS seems to play a critical role on seasonal variations in the light-absorbing properties of organic aerosols as well as the biogeochemical impact of WSOC on Earth’s surface.


2019 ◽  
Vol 9 (7) ◽  
pp. 1443 ◽  
Author(s):  
Chang Jung ◽  
Ji Lee ◽  
Junshik Um ◽  
Seoung Lee ◽  
Young Yoon ◽  
...  

We estimated source-based aerosol optical properties for polydisperse aerosols according to a chemical-species-resolved mass contribution method based on source apportionment. We investigated the sensitivity of aerosol optical properties based on PM2.5 (particulate matter that have a diameter of less than 2.5 micrometers) monitoring results. These aerosols were composed of ions, metals, elemental carbon, and water-soluble organic carbon which includes humic-like carbon substances and water-soluble organic carbon. We calculated aerosols’ extinction coefficients based on the PM2.5 composition data and the results of a multivariate receptor model (Solver for Mixture Problem model, SMP). Based on the mass concentration of chemical composition and nine sources calculated with the SMP receptor model, we estimated the size-resolved mass extinction efficiencies for each aerosol source using a multilinear regression model. Consequently, this study quantitatively determined the size resolved sources contributing to the apportionment-based aerosol optical properties and calculated their respective contributions. The results show that source-resolved mass concentrations and extinction coefficients had varying contributions. This discrepancy between the source-based mass concentration and extinction coefficient was mainly due to differences between the source-dependent aerosol size distribution and the aerosol optical properties from different sources.


Author(s):  
Vikram Pratap ◽  
Amy E. Christiansen ◽  
Annmarie G. Carlton ◽  
Sara Lance ◽  
Paul Casson ◽  
...  

Cloud cycling plays a key role in the evolution of atmospheric particles and gases, producing secondary aerosol mass and transforming the optical properties and impacts of aerosols globally.


2013 ◽  
Vol 13 (5) ◽  
pp. 13773-13798 ◽  
Author(s):  
X. Ding ◽  
X.-M. Wang ◽  
Q.-F. He ◽  
X.-X. Fu ◽  
B. Gao

Abstract. Water-soluble organic carbon (WSOC) is a major component of carbonaceous aerosols. However, the detailed information of WSOC origins is still unclear. In the current study, fine particles (PM2.5) were collected at one sub-urban and two rural sites in the Pearl River Delta (PRD) region, south China during fall–winter 2008 to measure WSOC and organic tracers of biomass burning (BB) and secondary organic aerosols (SOA) from isoprene, monoterpenes, β-caryophyllene, aromatics and 2-ring polycyclic aromatic hydrocarbons (PAHs). WSOC concentrations ranged from 7.63 to 11.5 μg C m−3 and accounted for 38.8–57.9% of organic carbon (OC). Both WSOC and water-insoluble organic carbon (WIOC) exhibited higher levels at the sub-urban site than the rural sites. Subtracting BB-derived WSOC (WSOCBB) from measured WSOC, secondary OC (SOC) and primary OC (POC) were estimated that POC exhibited dominance over SOC and contributed 68–79% to OC. Significant correlation between WSOC and EC was observed, suggesting that BB could have important contributions to ambient WSOC in the PRD region during fall–winter. Organic tracers were applied to do source apportionment of WSOC, which further confirmed that BB was the dominant contributor, accounting for 42–47% of measured WSOC. SOC estimated by SOA tracers totally contributed 22–40% of WSOC, among which anthropogenic SOC (sum of aromatics and 2-ring PAHs, 18–25%) exhibited dominance over biogenic SOC (sum of isoprene, monoterpenes and β-caryophyllene, 4–15%). The unexplained WSOC (18–31%) showed a positive correlation with POC, indicating that this portion might be associated with POC aging.


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