Numerical simulation on the long-term variation of radioactive cesium concentration in the North Pacific due to the Fukushima disaster

Kawamura, Hideyuki  ; Kobayashi, Takuya ; Furuno, Akiko   ; Usui, Norihisa*; Kamachi, Masafumi*

Numerical simulations on oceanic radioactive cesium dispersions in the North Pacific were conducted with a focus on the long-term variation of the radioactive cesium concentration after the Fukushima disaster. It was suggested that the Cs concentration had already been reduced to the pre-Fukushima background value in the wide area within the North Pacific 2.5 years after the Fukushima disaster.