A research on acid rain and acid snow.2.Inorganic ion components in rain drops in the yellow sand season.

Abstract

The so-called Kosa ("yellow sand") is transported to the Korea Peninsula and the Japan Islands following wind storms above the desert of the Asian Continent every spring. In this study, samples of the rain water during Kosa periods in 1985 to 1988 were collected at Kanazawa, Japan and Seoul, Korea. The concentrations of inorganic ions in the rain water during Kosa periods were compared with those during non-Kosa periods. The pH values of the rain water during Kosa periods were higher than those during non-Kosa periods. The non-seawater-derived concentrations of Ca2+, Mg2+, Na+ and K+ in the rain water during Kosa periods were higher than those during non-Kosa periods. The concentrations of nss-Ca2+ and nss-Mg2+ during Kosa periods at Seoul were higher than those at Kanazawa, but the ratios of the nss-Ca2+ concentration to the nss-Mg2+ concentration at Kanazawa and Seoul were almost equal. The concentrations of nss-SO42-, NO3- and F- were relatively higher in the rain water during Kosa periods. It was considered that these anions were adsorbed and/or absorbed in the long range transport process of Kosa aerosols. The acidity of the rain water before the effect of Kosa was tried to be estimated by the analysis of chemical equilibrium between the atmosphere and the rain drops.