A Study of the Impact of the Fukushima Nuclear Leak on East China Coastal Regions

摘要

The nuclear leak in Fukushima, Japan, which occurred on 11 March 2011, had disastrous impacts in many regions of the northern hemisphere. In this study, a highly resolved, one-way nesting model incorporating tides is set up with the Regional Ocean Modeling System (ROMS) to simulate and predict the potential impact of the disaster on the East China Sea (ECS), with the large domain covering the entire North Pacific. Of the four main waterways, namely Taiwan Strait, the waterway east of Taiwan, Tokara Strait, and Tsushima Strait, the first two have net fluxes of radionuclides into the ECS, while the other two have net outward transport during the entire 14-year period of the simulation (2011-2025). Differing from previous studies, we have taken into account background radionuclides in this model; the results agree well with available observations. Based on the simulation, the radioactive material has arrived in the ECS. The amount will reach its peak in 2019 and late in 2021 will return to its original state before the accident. Temporally it has a clear seasonal variability, with peaks usually appearing during winter. Spatially it is not homogeneously distributed, and the concentration has local maxima along the coasts of Jiangsu and Zhejiang, which are the most populous regions of China; a conspicuous feature is the Subei Bank high in summer. This study is expected to help form policy for rapid response to such disasters.