四国•高知県の梶ケ森山頂における雨氷の化学成分濃度

摘要

年間観測件数の少ない雨氷現象は一般に均質で透明な氷層が地物に付着した現象であり，過冷却した霧雨又は雨(着氷性の霧雨又は雨)が0℃以下又は0℃よりわずかに高い温度(過冷却でない場合は0℃以下)の地面や地物に当たって凍結する降水の一種である.雨氷の発生時の気圧配置としては，二つ玉低気圧や南岸低気圧による場合が多く，夜間に発生しやすい.%The second and third glaze events in Shikoku region were observed to have arisen during the early morning in March 9/2012 and January 14/2013, respectively. In order to obtain information about the concentrations of chemical constituents in glaze, one of the samples was collected from the summit of Mt. Kajigamori (ALT. 1400 m), where is the watershed protection forest of Riv. Yoshinogawa is located. The concentrations of major soluble ions and toxic elements, such as Cd and Pb, were analyzed. High concentrations of nss-SO_4~(2-) and Pb were observed with the back-trajectory over Middle and North China. The residues in the glaze were analyzed by a SEM-EDX technique. In the residue, various components of small spherical particulate were also found, indicating the presence of various origins of the fly-ash, including coal burning with the effect of long-range transport.