Abstract
Elevated particulate matter (PM) concentrations in urban atmosphere in Japan are associated with fine particles emitted and/or formed in an urban area and those transported from the Asian continents. It is thus important to know each contribution for the improvement of urban PM pollution. In this study, a new approach to evaluate transboundary PM pollution is developed based on the measurement of optical properties of fine particles such as SSA (Single Scattering Albedo) and B/N ratio (absorption coefficient/fine particle number concentration), and applied to Sapporo, Japan. The results suggest that during the observation period (June - Dec. 2014), transboundary pollution contributed more than 70% to the PM concentrations in Sapporo, and that transboundary pollution contribution has a seasonal variation with a decrease in summer and an increase in autumn. The approach is expected to serve as an important tool towards effective measures for PM pollution control in Japan.
