β線吸収法による浮遊粒子状物質の解析から黄砂飛来の評価 Studies on Estimation of Kosa Event from Analysis of Suspended Particulate Matter (SPM) by β-Ray Absorption Method
Studies on Kosa flying to Japan were performed by using the concentration of SPM monitor (DKK Inc., Model GRH-76) at 6 air pollution monitoring stations in Nara prefecture during the period from 1980 to 1993. Kosa event was able to be estimated to a certain extent when the maximum concentration of SPM in a day measured by SPM monitor of β-ray absorption method was high concentration. At Kosa event, in the comparison of SPM concentration by light scattering method with β-ray absorption method, β-ray absorption method was able to detect Kosa event, but light scattering method was not. Criteria of Kosa event by SPM concentration measured by SPM monitor of β-ray absorption method were as follows : SPM concentration in a wide area were appeared over 100 μg/m<SUP>3</SUP> simultaneously or were similar pattern (correlation coefficients were significant). The case over 100 μg/m<SUP>3</SUP> of SPM concentration measured by SPM monitor of β-ray absorption method throughout the whole area of Nara prefecture were 72 days during the period from 1987 to 1993. The number of Kosa event was the most (28 days) in 1988, and then became to be less year by year. It was found that the most Kosa event was in January, and the secondary was in April during the observation period in Nara.
- エアロゾル研究 = Journal of aerosol research
エアロゾル研究 = Journal of aerosol research 10(1), 41-50, 1995-03-20