Observation of annual changes in the concentrations of atmospheric NOx, SO2 and O3 in mountains around the Kyoto Basin after the collection with passive samplers (1996-2005)

Abstract

Continuous measurements of air pollutants [NOx (NO2, NO), SO2, and O3] 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 NOx, SO2, and O3 from 1996 to 2005 were analyzed. The seasonal changes in the concentrations of NO2 at mountains around the Kyoto basin showed winter maxima and summer minima. Atmospheric NO2 concentrations in the summer were higher in 2000 and those in the winter decreased after 2004. A positive relation was obtained between the NO2 concentrations and the formation days of a temperature-inversion layer. The concentrations of atmospheric SO2 in mountains around the Kyoto basin were lower than those of atmospheric NO2, and their seasonal changes were small. However, the concentrations increased from September 2000 to 2001. A large quantity of SO2 discharge by the eruption on Miyake Island may have affected the increase of atmospheric SO2 concentrations in Kyoto. Atmospheric O3 concentrations in the mountains around Kyoto basin have their origins in both O3 productions by photochemical reactions and stratospheric input. Furthermore, a sudden increase of O3 concentrations was observed when air mass may have been transported from China to Japan by backward trajectory analysis. © 2012 The Japan Society for Analytical Chemistry.