Spatiotemporal variations in atmospheric aerosols in East Asia: Identifying local pollutants and transported Asian aerosols in Osaka, Japan using DRAGON

Abstract. In this work, we document the spatial and temporal variations of atmospheric aerosols in East Asia, specifically focusing on the NASA/AERONET-Osaka site in March 2012 during the AERONET “DRAGON-Japan” campaign. Air pollution has become a serious issue in East Asia in recent years, with particular problems caused by fine particles having diameters of up to 2.5 μm (PM_2.5). Emissions of anthropogenic aerosols are known to increase with economic growth, whereas natural dust concentrations show significant variation with season and changing wind patterns. We focus on variations in the mass concentrations of particulate matter (PM) gathered by a sampler (SPM-613D) at the NASA/AERONET-Osaka site in March 2012, and have compositionally analyzed individual PM types using a scanning electron microscope (SEM) coupled with an energy dispersive X-ray analyzer (EDX). Our data show that Asian aerosols derived from distal sources were unequivocally detected in Japan on 11^th March 2012. Such pollutants can be carried by winds from continental China and subsequently merge with local emissions, thus accentuating air pollution problems.