Abstract
A three dimensional Eulerian grid model for a long-range transportation of air pollutants was used to evaluate the amounts and the source-receptor relationships of sulfate and nitratedepositions in East Asia. The analytical domain was divided into 6 regions (5 countries and the others). Contribution of deposition to receptors from each country sources and sources contribution to total deposition in each country in 1990 were estimated. Furthermore, the area including Japan was divided into 5 regions and seasonal source contribution to deposition in each region was evaluated.
10896 Gg.S of SOx and 2886 Gg.N of NOx were disharged, and 8885 Gg.S (81.6%) of sulfate and 2347 Gg.N (81.9%) of nitrate were deposited in the domain. The ratios between wet and dry depositions were 67% and 33% for sulfate and 56% and 44% for nitrate respectively. The large amount of sulfate and nitrate were deposited in China, and the deposition flux in South Korea and Taiwan were relatively large among East Asian countries. In Japan, the contribution of domestic anthropogenic sources to deposition of sulfate was estimated as 36.6%, and the contribution of volcanic source and Chinese source were very large. Contribution of abroad sources to deposition of sulfate and nitrate in Japan was relatively high in Winter and very low in Summer. Contribution of abroad sources to deposition in the coastal area of the Sea of Japan was especially high in Winter.
