Abstract
Atmospheric aerosols affect global warming by scattering and absorption of solar radiation. In this research, the variation of atmospheric turbidity coefficient, which is in proportion to aerosol amount, was investigated at 5 areas in Japan (Sapporo, Nemuro, Shionomisaki, Tosashimizu, Ishigakijima) from 1996 to 2004. Atmospheric turbidity coefficient increased in spring and early summer, while decreased generally in autumn and winter. Further, long-term variation of atmospheric turbidity coefficient was investigated from 1950s. Atmospheric turbidity coefficient increased when the air pollution deteriorated all over the country in 1960s, and two volcanic eruptions, Mt. El Chichon in 1982 and Mt. Pinatubo in 1991. Recently atmospheric turbidity coefficient has been decreased to the level before the eruptions.