1997 年 12 巻 3 号 p. 197-208
Aerosols and gaseous samples were collected weekly by a four stage filter pack method in Nara City, a small inland city, during the period from July 1993 to June 1996, and at Mt. Ohdaigahara, a clean mountainous area during the summers and autumns from June 1995 to October 1996; the concentrations of soluble ionic components (SO42-, NO3-, Cl-, Na+, NH4+, K+, Ca2+ and Mg2+) of aerosols and gases (SO2, HNO3, HCl and NH3) were derived. The concentrations of aerosols and gases varied seasonally in Nara City; specifically, the SO2 concentration was high in winter and low in summer and the SO42- concentration of aerosols was high in summer and low in winter. HNO3, HCl and NH3 concentrations were high in summer and low in winter. On the other hand, NO3-, Cl- and NH4+ concentrations of aerosols were high in winter and low in summer. The ratio of concentrations of fine particle components such as SO42- and NH4+ at Mt. Ohdaigahara to those Nara City were not much lower than those of gases and the ratio was about 40% suggesting the long range transport of SO42- and NH4+. Average amount of dry deposition of SO42- and NO3- calculated by inferential method in Nara City were 0.80 and 1.6 mmol/m2/mo on bare ground, 0.96 and 1.7 mmol/m2/mo on agricultural land, 0.73 and 2.1 mmol/m2/mo on deciduous trees and 1.1 and 2.7 mmol/m2/mo on coniferous trees, respectively. Average SO42- and NO3- amount of deposition calculated by inferential method at Mt. Ohdaigahara were 0.10 and 0.41 mmol/m2/mo on bare ground, 0.15 and 0.42 mmol/m2/mo on agricultural land, 0.18 and 0.55 mmol/m2/mo on deciduous trees and 0.27 and 0.64 mmol/m2/mo on coniferous trees, respectively.