Southward spreading of the Fukushima-derived radiocesium across the Kuroshio Extension in the North Pacific

作者：Kumamoto Yuichiro^*; Aoyama Michio; Hamajima Yasunori; Aono Tatsuo; Kouketsu Shinya; Murata Akihiko; Kawano Takeshi

来源：Scientific Reports, 2014, 4(1): 4276.

DOI：10.1038/srep04276

The accident of the Fukushima Dai-ichi nuclear power plant in March 2011 released a large amount of radiocesium into the North Pacific Ocean. Vertical distributions of Fukushima-derived radiocesium were measured at stations along the 149 degrees E meridian in the western North Pacific during the winter of 2012. In the subtropical region, to the south of the Kuroshio Extension, we found a subsurface radiocesium maximum at a depth of about 300 m. It is concluded that atmospheric-deposited radiocesium south of the Kuroshio Extension just after the accident had been transported not only eastward along with surface currents but also southward due to formation/subduction of subtropical mode waters within about 10 months after the accident. The total amount of decay-corrected Cs-134 in the mode water was an estimated about 6 PBq corresponding to 10-60% of the total inventory of Fukushima-derived Cs-134 in the North Pacific Ocean.

• 出版日期2014-3-4
• 单位中国气象科学研究院