Characteristics, Origin and Transport of Asian Dust Particles in 2006 and 2007, Korea

Asian dust particles transported to Korea are usually known to be derived from the arid regions of West and central China and Mongolia. Dust particles were collected using high-volume air samplers at three stations located on islands in the west, east, and south off Korea. Particles were also collected from seawater in April 2006 during the dust event. Dust particles were observed by SEM (Scanning Electron Microscope), and major component composition was measured semiquantitatively by EDS (Energy Dispersive X-ray Spectroscopy) attached to SEM. During dust events, dusts contain poorly rounded and low-sphericity mineral grains. In addition, dust mass and grain size tend to increase during dust events. According to the result of major element analysis, during dust events Mg and Si usually increase while during non-dust event period S, Cl, and Ti increase. Al, Ca and K compositions show no typical trend at three stations, so they are thought to reflect regional difference. Fe shows no distinctive change all year round, suggesting that it does not seem to reflect dust event well. Correlation analysis of elemental compositions suggests that dusts collected from Baekryeong (west), and Jeju (south), and Ulleung (east) Islands have somewhat different characteristics, probably caused by difference in the path and velocity of airmass among three stations, supported by backward trajectory analysis. Isotopic ratios of 143Nd/144Nd, and 87Sr/86Sr of dust particles collected from seawater during the April dust event, 2006 have similar compositions with sediments of the Taklmakan and Gobi deserts. Considering backward trajectory result of airmass, the dusts blown to Korea in April 2006 are inferred to have been originated from the Gobi desert in Mongolia.