Radiocesium in the western subarctic area of the North Pacific ocean, Bering Sea, and Arctic Ocean in 2015 and 2017

• Published in: Polar Science
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2019
• Subjects: Fukushima Dai-ichi nuclear power plant; Radiocesium; The western subarctic area of the north Pacific; Arctic ocean; Bering sea; Arctic; Arctic Ocean; Bering Sea; Pacific; Fukushima; Pacific Arctic; Polar Science; Subarctic
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=15938; http://id.nii.ac.jp/1291/00015830/

We measured dissolved radiocesium (134Cs and 137Cs) in seawater collected in the western subarctic area of the North Pacific Ocean, Bering Sea, and Arctic Ocean in 2015 and 2017. The radiocesium released from the accident of the Fukushima Dai-ichi nuclear power plant (FNPP1) in March 2011 was still observed in the surface seawater of the western subarctic area and Bering Sea. Between 2015 and 2017, the radiocesium concentration decreased and increased in the western subarctic area and the Bering Sea, respectively. The increase in the Bering Sea was probably derived from the long-range transport of the FNPP1-derived radiocesium into the Bering Sea with the subarctic gyre circulation in the North Pacific. The FNPP1-derived radiocesium was not detected in the Arctic Ocean in 2015 unlike that observed in 2014, which suggests a restricted transport of the FNPP1-derived radiocesium from the Bering Sea to the Arctic Ocean in 2015. The significant elevation in the radiocesium concentration in the Bering Sea in 2017 associated with the long-range transport implies the increase in the transport of the FNPP1-derived radiocesium into the Arctic Ocean in the future.