On the acidity of atmospheric aerosol particles and its global distribution.

Research Project

Project/Area Number	58460045
Research Category	Grant-in-Aid for General Scientific Research (B)
Allocation Type	Single-year Grants
Research Field	気象・海洋・陸水学
Research Institution	Nagoya University
Principal Investigator	ONO Akira water Research Institute, 水園科学研究所, 教授 (50111860)
Co-Investigator(Kenkyū-buntansha)	ISHIZAKA Yutaka Water Research Institute, 助手 (50022710) TANAKA Hiroshi Water Research Institute, 助教授 (00115594)
Project Period (FY)	1983 – 1984
Project Status	Completed (Fiscal Year 1986)
Budget Amount *help	¥4,100,000 (Direct Cost: ¥4,100,000) Fiscal Year 1984: ¥1,500,000 (Direct Cost: ¥1,500,000) Fiscal Year 1983: ¥2,600,000 (Direct Cost: ¥2,600,000)
Keywords	Acidity of aerosol particles / sulfuric acid mist / 硫酸ミスト / 降水の酸性化
Research Abstract	In order to clarify the acidity of global aerosol particles, it is important to observe maritime particles which are less influenced by human acfivifies. We obtained by the airplane observation in 1983 that the sulfate particles may be prodominant and exist as <H_2SO_4> mist. This year we fried to have more direct evidence whether maritime aerosol particles are constituted of <H_2SO_4> mist. A calcium-thin film method (Ono et. al., 1983) was used to selectively identify <H_2SO_4> mist. Airplane observations were carried out in August, 1984 from the Hachijojima Island to 19゜N along a longitude of 140 degree. Obtained results are as follows. (1) In the area sulfate particles (as photochemical secondary particles) are predominant. A large difference was seen in the acidity bounding the Iwojima Island. (2) <H_2SO_4> mists were prodominant in the south of the Iwojima Island. On the other hard <(NH_4)_2> <SO_4> particles were predominant in the north of the island. The former reacts with Cathin films and morphologically shows satellite structure, but the latter does not. (3) Tracing back of the air parcel on 850 mb surface shows that pure maritime air parcels are seen in the south of the Iwojima Island while the air parcels in the north of the island are polluted by the mainland of Japan. This is the first finding in the world.