2008 Volume 52 Pages 205-210
The source area of acidic oxide in Japan is likely to differ with the season. It is considered that acidic oxide in the East Japan is mainly brought by advection from the East-Asia continent in winter. In summer, it may be brought by advection from Yokkaichi seaside industrial area in the central part of Japan. In this study, transportation process of the acidic oxide in the East Japan was investigated by an advection and dispersion model (HYSPLLIT4) . The advection process of acidic oxide in each season also was investigated through trajectory analysis and through numerical transport simulations. The acidity of precipitation tends to be higher as a whole in summer than in winter in the East Japan, while the concentration of acid ion increases in winter in part of the northern Kanto region. The results of the trajectory analysis and transport simulations shows that the source area of sulfur dioxide transported to the East Japan in winter is likely to be the northern part of China.
