Vertical distributions of 90Sr and 137Cs in Sea of Japan/East Sea (SOJ/ES) water in the period of 1977-2010 exhibited a typical diffusion shape with surface/subsurface maxima and decreasing values with increasing depth. Apparent vertical diffusion coefficients (AVDCs) and apparent initial surface fluxes (AIFs) of 90Sr and 137Cs, which were estimated using a curve-fitting method from a vertical diffusion model, showed temporal and spatial variability. A diffusion depth introduced for understanding of vertical movements of 90Sr and 137Cs in the SOJ/ES well correlated with corresponding AIFs, suggesting that spatial variations of the 90Sr and 137Cs inventories have been governed by oceanic conditions such as changes in AVDCs, which may be related with eddy field, characterizing the SOJ/ES. The temporal changes of the AVDCs suggest that the production of eddies increased during the 2000s comparing with that in the 1990s. These observations represent the first applications of radionuclides as tracers in production of oceanic eddies.

中文翻译：

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90Sr和137Cs是日本/东海中海洋涡流的示踪剂。

1977-2010年日本海/东海（SOJ / ES）水中90Sr和137Cs的垂直分布表现出典型的扩散形，具有表面/地下最大值，并且随着深度的增加而减小。使用垂直扩散模型的曲线拟合方法估算的90Sr和137Cs的表观垂直扩散系数（AVDC）和表观初始表面通量（AIF）显示出时间和空间变异性。为了解SOJ / ES中90Sr和137Cs的垂直运动而引入的扩散深度与相应的AIF很好地相关，这表明90Sr和137Cs清单的空间变化已受海洋条件的影响，例如AVDC的变化，这可能与涡流场，表征SOJ / ES。AVDC的时间变化表明，与1990年代相比，在2000年代涡流的产生增加了。这些观察结果代表了放射性核素作为示踪剂在海洋涡旋生产中的首次应用。