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 (388Kb)
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81,580,000 Yen
To clarify the long-range transport process of pollutants related with acid precipitation in the east Asia, the long-range transport model has been developed. The transport model was consisted from two submodels, one was meteorological model and the other was dispersion model. The Lagrangian Particle was adopted in the dispersion model, and the random-walk method was used for the calculation of vertical diffusion process. The Monte Carlo calculation was adopted for dry deposition process. For wet deposition process, only below cloud scavenging was considered. The transformation process from sulfur dioxide to sulfate was also included in the model.
After making some validation of the model, the numerical simulation was performed for the transport process of sulfur oxides in east Asia all the year around 1985. The calculation was carried out by excepting the domestic emissions for evaluating the contribution on acid deposition in Japan from the emission in vicinal countries. The annual dry and wet depositions of sulfur oxides at several areas in Japan were evaluated.
The result of numerical simulation showed that the annual wet deposition of sulfur oxides in Japan originated in the emission in vicinal countries was 0.1-0.3 g/m2. The calculated wet deposition of sulfur oxides was one order lower than observed wet deposition of sulfate.
Meanwhile, to grasp the vertical transport of sub-grid scale originated in topography, the field observation on vertical transport of aerosol was performed by using transportable and aircraft loading lidars. The observational results were reflected in the model.
Acid rain, Long-range Transport, Numerical model, Wet depodition