2005 年 20 巻 4 号 p. 324-332
In order to investigate the characteristics of episodically yellow rain in Asian dust storm event, the size-resolved samples of raindrops were collected on a ground level in Kyoto. The soluble and insoluble fractions in size-resolved raindrops were analyzed by PIXE. Model calculations were performed to determine the elemental mass concentration as a function of raindrop size. It was found that the elemental concentrations in both soluble and insoluble fractions have a strong raindrop size dependence. S and Cl exhibit the predominantly higher mass loading in soluble fraction. Relatively good agreement was obtained between measured and calculated results for Si, S, and K. Furthermore, the chemical properties of the individual solid particles retained in raindrops were determined by the XRF microbeam system equipped at SPring-8, BL-37XU.