Yamamoto Masayoshi, Sakaguchi Aya, Sasaki Keiichi, Hirose Katsumi, Igarashi Yasuhito, Kim Chang Kyu
Low Level Radioactivity Laboratory, K-INET, Kanazawa University, Nomi, Ishikawa 923-1224, Japan.
J Environ Radioact. 2006;86(1):110-31. doi: 10.1016/j.jenvrad.2005.08.001. Epub 2005 Sep 21.
Monthly depositional fluxes of (210)Pb and (7)Be at Tatsunokuchi, Japan which faces the Japan Sea were studied over a 12-year period from 1991 to 2002. The data were compared with the spatial variability of these fluxes at Taejon in Korea and at 11 other sites in Japan from Ishigaki of the southern islands of Okinawa to Wakkanai of the northern end of Hokkaido over a 2-year period from 2000 to 2001. The monthly depositions of both (210)Pb and (7)Be at Tatsunokuchi revealed very similar seasonal variations with a single peak; both depositions were high in winter and low in summer. This phenomenon was found to be not transient but stationary. The deposition of these nuclides was much greater on the Japan Sea side of Japan than on the Pacific Ocean side. The cause for high deposition of (210)Pb and (7)Be in winter might be explained by a combination of a series of the following processes: blowing out of air masses with a high (210)Pb concentration near the surface layer over the continent by strong winter monsoons, additional flow of cold air masses with high (7)Be concentration at high latitude, well-mixing with generation of ascending current and convection clouds over the Japan Sea, and heavy snowfalls accompanying them.
1991年至2002年的12年间，对日本面向日本海的馆之口的（210）Pb和（7）Be的月沉积通量进行了研究。将这些数据与2000年至2001年的2年间韩国大田以及日本从冲绳南部岛屿的石垣到北海道北端的稚内等其他11个地点的这些通量的空间变异性进行了比较。馆之口的（210）Pb和（7）Be的月沉积量均呈现出非常相似的单峰季节性变化；两者的沉积量在冬季较高，在夏季较低。发现这种现象不是短暂的，而是稳定的。这些核素在日本日本海一侧的沉积量远大于太平洋一侧。冬季（210）Pb和（7）Be高沉积的原因可能由以下一系列过程共同解释：冬季强风将大陆表层附近（210）Pb浓度高的气团吹出，高纬度地区（7）Be浓度高的冷空气团的额外流动，与日本海上上升流和对流云的生成充分混合，以及伴随而来的大雪。
