Seasonal variation of <Superscript>228</Superscript>Ra/<Superscript>226</Superscript>Ra ratio in surface water from the East China Sea and the Tsushima Strait     

Mutsuo Inoue  Yusuke Nakano  Yoko Kiyomoto  Hisaki Kofuji  Yasunori Hamajima  Masayoshi Yamamoto 《Journal of Oceanography》2010,66(3):425-428

A total of 21 surface water samples were collected on the east side of the East China Sea (ECS) (3 sites) and at the Tsushima Strait (1 site), and ²²⁶Ra and ²²⁸Ra activities were measured using low-background γ-spectrometry. The ²²⁸Ra/²²⁶Ra ratios among the samples exhibited notable seasonal variation (²²⁸Ra/²²⁶Ra = 0.2–2.6) accompanying changes of salinity (31.7–34.7). Seasonal water circulation within the ECS is hypothesized to cause the change by altering the mixing ratio of ²²⁸Ra-rich continental shelf water and ²²⁸Ra-poor Kuroshio water.  相似文献