title: Single-particle characterization of summertime Antarctic aerosols collected at King George Island using quantitative energy-dispersive electron probe X-ray microanalysis and attenuated total reflection Fourier transform-infrared imaging techniques.
abstract: Single-particle characterization of Antarctic aerosols was performed to investigate the impact of marine biogenic sulfur species on the chemical compositions of sea-salt aerosols in the polar atmosphere. Quantitative energy-dispersive electron probe X-ray microanalysis was used to characterize 2900 individual particles in 10 sets of aerosol samples collected between March 12 and 16, 2009 at King Sejong Station, a Korean scientific research station located at King George Island in the Antarctic. Two size modes of particles, i.e., PM(2.5-10) and PM(1.0-2.5), were analyzed, and four types of particles were identified, with sulfur-containing sea-salt particles being the most abundant, followed by genuine sea-salt particles without sulfur species, iron-containing particles, and other species including CaCO(3)/CaMg(CO(3))(2), organic carbon, and aluminosilicates. When a sulfur-containing sea-salt particle showed an atomic concentration ratio of sulfur to sodium of >0.083 (seawater ratio), it is regarded as containing nonsea-salt sulfate (nss-SO(4)(2-)) and/or methanesulfonate (CH(3)SO(3)(-)), which was supported by attenuated total reflection Fourier transform-infrared imaging measurements. These internal mixture particles of sea-salt/CH(3)SO(3)(-)/SO(4)(2-) were very frequently encountered. As nitrate-containing particles were not encountered, and the air-masses for all of the samples originated from the Pacific Ocean (based on 5-day backward trajectories), the oxidation of dimethylsulfide (DMS) emitted from phytoplanktons in the ocean is most likely to be responsible for the formation of the mixed sea-salt/CH(3)SO(3)(-)/SO(4)(2-) particles.
authors.affiliation: Department of Chemistry, Inha University, Yonghyun Dong, Nam Gu, Incheon, South Korea.
authors.forename: Shila
authors.initials: S
authors.lastname: Maskey
authors.forename: Hong
authors.initials: H
authors.lastname: Geng
authors.forename: Young-Chul
authors.initials: YC
authors.lastname: Song
authors.forename: Heejin
authors.initials: H
authors.lastname: Hwang
authors.forename: Young-Jun
authors.initials: YJ
authors.lastname: Yoon
authors.forename: Kang-Ho
authors.initials: KH
authors.lastname: Ahn
authors.forename: Chul-Un
authors.initials: CU
authors.lastname: Ro
mesh_terms: D000336:Aerosols / Q000032:analysis*; D000864:Antarctic Regions; D004577:Electron Probe Microanalysis / Q000379:methods*; D005843:Geography; D007501:Iron / Q000737:chemistry; D010316:Particle Size; D052638:Particulate Matter / Q000737:chemistry; D012015:Reference Standards; D012621:Seasons; D017550:Spectroscopy, Fourier Transform Infrared; D013431:Sulfates / Q000737:chemistry; D013447:Sulfites / Q000737:chemistry; D013455:Sulfur / Q000032:analysis; D013997:Time Factors
chemical_list: D000336:Aerosols; D052638:Particulate Matter; D013431:Sulfates; D013447:Sulfites; D013455:Sulfur; D007501:Iron