Abstract
Four separate series of observations of surface NO2 and ozone were made at inland (Sudagai) and seashore (Tomisaki) stations in the central part of Honshu, Japan.
The results of NO2 determination showed a diurnal variation with two Maxima respectively at about one hour after sunrise and one to two hours after sunset. The NO2 concentrations on the evenings of fine days were extraordinarily high when the snow around the inland station was gradually melting. On the other hand, the concentrations in maritime air in winter were very low, being 1.5, ugNO2/m3 on the average when there was a strong wind with a prevailing SW or SSW-component. At the inland station, the winter and the summer average values were the same, being 3.6μgNO2/m3, and the average values in early autumn and winter at the seashore station were respectively 3.7 and 7.3μgNO2/m3.
At the inland station the average concentrations of ozon e during the daytime in winter and summer were respectively 23 and 26μgNO2/m3. These values are lower than those in early autumn and winter at the seashore station, though the altitude of the former station is 701 meters above the sea level. This is explained by taking the topographic situation of the inland station into consideration.
