富士山の谷風によるエアロゾルの輸送量

抄録

In order to reveal the contribution of valley wind to the concentration of aerosol at the top of Mt. Fuji from the lower areas, field observations were performed at the summit station (3,776 m a.s.l.) , 7.8th shelter (3,255 m a.s.l.) , and Tarobo shelter (1,300 m a.s.l.) on the mountain in the summer of 2007. We quantitatively evaluated the amount of aerosols transported from the lower areas to the top of Mt. Fuji by a valley wind using the concentrations and the meteorological parameters measured at each station. During the observation when a valley wind blew up, the concentration at the 7.8th shelter first rose and then that at the summit station increased for several days. A model analysis of transported aerosols showed that the transport of aerosols by a valley wind takes place with their dilution or supply. A model analysis based on particle dilution for the transported aerosols with the diameter of about 400 nm to which the contribution of supply is small showed that about 85 % of aerosols at the summit are transported from the lower areas. These results were also confirmed by the chemical analysis of aerosols sampled at the summit and Tarobo shelter during the observation in the summer of 2008.