Single-Particle Characterization of Summertime Antarctic Aerosols Collected at King George Island Using Quantitative Energy-Dispersive Electron Probe X-ray Microanalysis and Attenuated Total Reflectio

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• 作者：Shila Maskey ; Hong Geng ; Young-Chul Song ; HeeJin Hwang ; Young-Jun Yoon ; Kang-Ho Ahn ; Chul-Un Ro
• 刊名：Environmental Science & Technology
• 出版年：2011
• 出版时间：August 1, 2011
• 年：2011
• 卷：45
• 期：15
• 页码：6275-6282
• 全文大小：980K
• 年卷期：v.45,no.15(August 1, 2011)
• ISSN：1520-5851

文摘

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鈥?0 and PM_1.0鈥?.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 CaCO₃/CaMg(CO₃)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-SO₄^{2鈥?/sup>) and/or methanesulfonate (CH₃SO₃鈥?/sup>), which was supported by attenuated total reflection Fourier transform-infrared imaging measurements. These internal mixture particles of sea-salt/CH₃SO₃鈥?/sup>/SO₄2鈥?/sup> 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/CH₃SO₃鈥?/sup>/SO₄2鈥?/sup> particles.}