数値シミュレーションモデルRAMS/HYPACTによる東アジアにおける硫黄化合物の年間ソース・リセプター解析

抄録

We examined the annual budget and source-receptor relationships for sulfur in East Asia using a regional chemical transport model (HYPACT) coupled with the Regional Atmospheric Modeling System (RAMS). Model results are compared with the annual observation data, which are the daily concentrations of particulate SO₄^2- at Osaka and the annual SO₄^2- deposition measured by several organizations in Japanese Islands. HYPACT can reproduce the day-to-day variations of SO₄^2- concentration and the annual amount of SO₄^2- wet deposition. The annual spatial distributions of the concentration and deposition for SO₂ and SO₄^2- were estimated in 1995. The general features of distribution for SO₂ concentrations are similar to those for SO₄^2-. Both SO₂ and SO₄^2- concentrations are highest in the eastern part of China and is moderately high over the East China Sea and the western part of Japan. In contrast, the sulfur deposition distribution is completely different from the concentration distributions, because the wet deposition is strongly influenced by rainfall amount. Annual sulfur deposition in Japan is 49% from China, 21% from Japan, 13% from volcano and 12% from North and South Korea.