In this paper we present evidence that Asian dusts can become more absorbing aerosols when mixed with pollutants. Spectral direct/diffuse solar radiations were measured on April 7, 2000 at Anmyeon-Do, Korea, when a narrow and heavy dust band moved through the Anmyeon measurement site. Lowest SSA values (about 0.91) are found within the dust band, while comparatively high values (up to 0.97) are found outside over the non-dust area at about 300 km away from the dust band. Considering that the air masses passed through the Anmyeon site took nearly the same path through the Beijing area, obtained results strongly suggest that there may be interactions between air pollutants and mineral dust aerosols that lead to the decreased SSA and thus to the more solar absorption by dust aerosols. In other words, Asian dusts tend to become darkened after mixing with pollutant particles produced over the industrial /urban area of China.
2007 by Meteorological Society of Japan