福島第一原子力発電所を放出源とする放射性セシウム137の沿岸域での分散特性

抄録

The 2011 Tohoku earthquake and the associated tsunami caused a severe nuclear accident at the Fukushima Daiichi Nuclear Power Plant (1F), leading to radioactive water leaking into the sea. We conduct a triple nested high-resolution numerical hindcast to assess oceanic dispersion of the leaked cesium-137 (¹³⁷Cs) in the coastal marginal sea, and successfully reproduce fluctuations of ¹³⁷Cs concentration. While an alongshore ¹³⁷Cs concentration PDF indicates a prevailing northward transport, a ¹³⁷Cs flux budget analysis exhibits that the cumulative alongshore flux is much greater than the offshore flux with latitudinal asymmetry due to the eddy transport, suggesting that ¹³⁷Cs tend to remain in the coastal zone.