초록 |
This study investigated physicochemical and optical characteristics for three episodes of Asian dust, stagnant haze and long-range transport haze and for one clean day. $PM_{10}$ mass concentration during Asian dust and two haze days was increased by 2~9 times compared to that of clean episode. During Asian dust episode, coarse particle concentration was increased and the mass concentration of calcium in a coarse mode ( $1.8{ sim}10{ mu}m$ ) was $5.4{ mu}g/m^3$ which was 7 times higher than that of clean episode. The calcium was presented as a form of $CaCO_3$ in a coarse mode. During the two haze episodes, fine particle ( $1.8{ mu}m$ ) concentration was increased and secondary inorganic pollutants such as sulfate, ammonium and nitrate composed of 90% of the total ions. $(NH_4)_2SO_4$ and $NH_4NO_3$ were dominant in a fine mode for stagnant haze episode. But they were the most dominant form in both fine mode and coarse mode for long-range transport haze episode. According to the optical properties for each episode (Asian dust, stagnant haze and long-range transport haze) were classified as dust, black carbon and mixture, respectively. |