Seasonal Variation of Tritium and Major Elements in Snow and Precipitation in Niigata, Japan

In order to evaluate seasonal and regional variations in precipitation in Niigata City, 65 hourly precipitation samples were collected from October 2009 to June 2011 including two snow events. In this work, major ions （Na＋, K＋, Ca2＋, Mg2＋, NH4＋, SO4^2-, NO3- and Cl-） were combined with tritium （^3H or T） concentration （T specific activity） in both precipitation and snow, and transformation patterns of polluted air mass in Niigata region were revealed. The low level tritium in precipitation was measured by a distillation process and an electrolytic enrichment process. Each tritium concentration in the precipitation sample thus obtained was measured by liquid scintillation counter. On the basis of the above measurement and analysis, it was found that the tritium and nss （non-sea-salt） calcium concentrations showed a seasonal variation with a highest value in spring over one year.

非洲势力图

非洲区域划分北非:阿尔及利亚、埃及、利比亚、苏丹、突尼斯、西撒哈拉、摩洛哥、加那利群岛(西班牙属)、亚速尔群岛(葡萄牙属)西非:科特迪瓦、加纳、多哥、尼日利亚、尼日尔、布基纳法索、马里、毛里塔尼亚、塞内加尔、冈比亚、几内亚比绍、几内亚、塞拉利昂、利比里亚、贝宁、佛得角、圣赫勒拿(英属)中非:喀麦隆、安哥拉、民主刚果、刚果共和国、乍得、中非共和国、赤道几内亚、加蓬、圣多美和普林西比南非:南非、纳米比亚、博茨瓦纳、莱索托、斯威士兰东非:埃塞俄比亚、索马里、厄立特里亚、吉布提、坦桑尼亚、肯尼亚、乌干达、卢旺达、布隆迪、赞比亚、津巴布韦、马拉维、莫桑比克、马达加斯加、科摩罗、塞舌尔、毛里求斯、马约特和留尼汪(法属)