title: Source contributions and potential source regions of size-resolved water-soluble organic carbon measured at an urban site over one year.
abstract: In this study, 24 h size-segregated particulate matter (PM) samples were collected between September 2012 and August 2013 at an urban site in Korea to investigate seasonal mass size distributions of PM and its water-soluble components as well as to infer the possible sources of size-resolved water-soluble organic carbon (WSOC) using a positive matrix factorization (PMF) model. The potential source contribution function (PSCF) was also computed to identify the possible source regions of size-resolved WSOC. The seasonal average contribution of water-soluble organic matter to PM1.8was in the range from 12.7 to 19.7%, but higher (21.0%) and lower contributions (8.9%) were observed during a severe haze event and an Asian dust event, respectively. The seasonal mass size distribution of WSOC had a dominant droplet mode peaking at 0.55 μm and a minor coarse mode peaking at 3.1 μm. The droplet mode WSOC was found to strongly correlate with oxalate, SO42-, NO3-, and K+, suggesting that in-cloud processes and biomass burning emissions are important sources of droplet mode WSOC. This finding was verified by the results obtained using PMF models. Secondary organic aerosols (oxalate + SO42-+ NO3-) and biomass burning were the most important contributors (70.3%) to condensation mode WSOC. In the droplet mode, in-cloud processes and secondary NO3-(+biomass burning) were important sources of WSOC, contributing on average 46.4 and 25.9% to the WSOC, respectively. In the coarse mode, soil dust and secondary processes contributed 52.5 and 42.5% to the WSOC, respectively. The PMF analyses and PSCF maps of WSOC, SO42-, and K+indicate that condensation mode WSOC was mostly influenced by the secondary organic aerosols and biomass burning from both local and long-range transported pollutants, while droplet mode WSOC was primarily the result of atmospheric processing during the long range transport of biogenic and anthropogenic pollutants from the eastern regions of China.
authors.affiliation: Department of Environment and Energy Engineering, Chonnam National University, 77 Yongbong-Ro, Buk-gu, Gwangju 61186, Korea. park8162@chonnam.ac.kr.
authors.forename: Geun-Hye
authors.initials: GH
authors.lastname: Yu
authors.affiliation: Department of Environment and Energy Engineering, Chonnam National University, 77 Yongbong-Ro, Buk-gu, Gwangju 61186, Korea. park8162@chonnam.ac.kr.
authors.forename: Seungshik
authors.initials: S
authors.lastname: Park
authors.affiliation: Department of Atmospheric & Environmental Sciences, Gangneung-Wonju National University, Korea.
authors.forename: Kwon-Ho
authors.identifier: http://orcid.org/0000-0002-0844-5245
authors.initials: KH
authors.lastname: Lee
mesh_terms: D000336:Aerosols; D000393:Air Pollutants / Q000032:analysis* / Q000737:chemistry; D002244:Carbon / Q000032:analysis*; D002947:Cities; D004391:Dust; D004784:Environmental Monitoring / Q000379:methods; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis* / Q000737:chemistry; D056910:Republic of Korea; D012987:Soil; D012995:Solubility; D014867:Water / Q000737:chemistry
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D004391:Dust; D052638:Particulate Matter; D012987:Soil; D014867:Water; D002244:Carbon