Continuous measurements of air pollutants [NO
x (NO
2, NO), SO
2, and O
3] by passive samplers were made in the mountains around the Kyoto basin for the purpose of elucidating the effects of acidic deposition within various ecosystems. The sampling sites were Mt. Hiei, Mt. Daimonji, 4 other mountains and a clean site (Kuroda). The behavior and origin of atmospheric NO
x, SO
2, and O
3 from 1996 to 2005 were analyzed. The seasonal changes in the concentrations of NO
2 at mountains around the Kyoto basin showed winter maxima and summer minima. Atmospheric NO
2 concentrations in the summer were higher in 2000 and those in the winter decreased after 2004. A positive relation was obtained between the NO
2 concentrations and the formation days of a temperature-inversion layer. The concentrations of atmospheric SO
2 in mountains around the Kyoto basin were lower than those of atmospheric NO
2, and their seasonal changes were small. However, the concentrations increased from September 2000 to 2001. A large quantity of SO
2 discharge by the eruption on Miyake Island may have affected the increase of atmospheric SO
2 concentrations in Kyoto. Atmospheric O
3 concentrations in the mountains around Kyoto basin have their origins in both O
3 productions by photochemical reactions and stratospheric input. Furthermore, a sudden increase of O
3 concentrations was observed when air mass may have been transported from China to Japan by backward trajectory analysis.
View full abstract