Inverse estimation of source parameters of oceanic radioactivity dispersion models associated with the Fukushima accident.

FUKUSHIMA-ken (Japan); JAPAN

With combined use of the ocean-atmosphere simulation models and field observation data, we evaluate the parameters associated with the total caesium-137 amounts of the direct release into the ocean and atmospheric deposition over the Western North Pacific caused by the accident of Fukushima Daiichi nuclear power plant (FNPP) that occurred in March 2011. The Green's function approach is adopted for the estimation of two parameters determining the total emission amounts for the period from 12 March to 6 May 2011. It is confirmed that the validity of the estimation depends on the simulation skill near FNPP. The total amount of the direct release is estimated as 5.5-5.9x1015 Bq, while that of the atmospheric deposition is estimated as 5.5-9.7x10¹⁵ Bq, which indicates broader range of the estimate than that of the direct release owing to uncertainty of the dispersion widely spread over the Western North Pacific. [ABSTRACT FROM AUTHOR]

Copyright of Biogeosciences Discussions is the property of Copernicus Gesellschaft mbH and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)