INTERCOMPARISON OF NUMERICAL SIMULATIONS ON OCEANIC DISPERSION OF THE RADIOACTIVE CESIUM RELEASED BECAUSE OF THE FUKUSHIMA DISASTER

摘要

We conducted numerical simulations on oceanic dispersion of the radioactive cesium released because of the Fukushima disaster in the North Pacific. Two independent oceanic reanalysis data were used in the simulations. Both simulations suggested that the ~(137)Cs concentration had been reduced to the pre-Fukushima level around 2.5 years after the disaster. The intercomarison revealed that meso-scale eddies accompanied by the Kuroshio Extension may have efficiently diluted the radioactive cesium at the sea surface. The meso-scale eddies also played an important role in transporting the surface radioactive cesium into the intermediate layer.