Abstract
Peroxyacetyl Nitrate (PAN), measurement were made during the winter 1999 at Mt. Teine (1000m altitude) in Sapporo. Median concentration during February was 0.21ppb. Higher concentration >1.0ppb were sometimes observed with southerly wind and higher ozone concentrations. There was little difference between PAN concentration at Mt. Teine and surface concentration in Sapporo, which indicate wintertime PAN in Sapporo was not formed by local photochemistry. Results from concurrent measurements of aldehydes and ozone also indicate that variation of PAN during winter in Sapporo was regional in nature. From the results, we conclude at least during winter surface PAN measurement in Sapporo is a good indicator of photochemical state and long-range transport of polluted air mass in East Asia.
