2012 年 27 巻 1 号 p. 24-33
Over the past decade, considerable progress has been made in understanding sources and formation processes of water-soluble organic aerosol (OA) in the atmosphere. This review article discusses the current knowledge on chemical characteristics, formation processes, and physical properties of water-soluble OA. In particular, organic aerosols formed in cloud and aerosol water are suggested to contribute substantially to OA mass. The review emphasizes the important roles of water-soluble organics in secondary OA formation including aqueous-phase reactions through field and laboratory studies.