title: Aircraft measurement of organic aerosols over China.
abstract: Lower to middle (0.5-3.0 km altitude) tropospheric aerosols (PM2.5) collected by aircraft over inland and east coastal China were, for the first time, characterized for organic molecular compositions to understand anthropogenic, natural, and photochemical contribution to the air quality. n-Alkanes, fatty acids, sugars, polyacids are detected as major compound classes, whereas lignin and resin products, sterols, polycyclic aromatic hydrocarbons, and phthalic acids are minor species. Average concentrations of all the identified compounds excluding malic acid correspond to 40-50% of those reported on the ground sites. Relative abundances of secondary organic aerosol (SOA) components such as malic acid are much higher in the aircraft samples, suggesting an enhanced photochemical production over China. Organic carbon (OC) concentrations in summer (average, 24.3 microg m(-3)) were equivalent to those reported on the ground sites. Higher OC/EC (elemental carbon) ratios in the summer aircraft samples also support a significant production of SOA over China. High loadings of organic aerosols in the Chinese troposphere may be responsible to an intercontinental transport of the pollutants and potential impact on the regional and global climate changes.
authors.affiliation: Institute of Low Temperature Science, Hokkaido University, Kita 19, Nishi 8, Kita-ku, Sapporo 060-0819, Japan.
authors.forename: Gehui
authors.initials: G
authors.lastname: Wang
authors.forename: Kimitaka
authors.initials: K
authors.lastname: Kawamura
authors.forename: Shiro
authors.initials: S
authors.lastname: Hatakeyama
authors.forename: Akinori
authors.initials: A
authors.lastname: Takami
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
mesh_terms: D000336:Aerosols; D000393:Air Pollutants / Q000032:analysis*; D000401:Aircraft; D000473:Alkanes / Q000032:analysis; D002241:Carbohydrates / Q000032:analysis; D002681:China; D004784:Environmental Monitoring; D005227:Fatty Acids / Q000032:analysis; D008031:Lignin / Q000032:analysis; D010795:Phthalic Acids / Q000032:analysis; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis; D013261:Sterols / Q000032:analysis
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D000473:Alkanes; D002241:Carbohydrates; D005227:Fatty Acids; D010795:Phthalic Acids; D011084:Polycyclic Aromatic Hydrocarbons; D013261:Sterols; D008031:Lignin