福岛核泄漏事件对中国海污染的研究

A study of the possible radioactive contamination in the China Seas from the Fukushima nuclear disaster

2011年3月11日日本地震和海啸导致了日本福岛核电站核放射性物质泄漏事件.利用ROMS区域海洋模式对北太平洋环流进行模拟,并在此流场中加入核放射性污染物进行测试核放射性污染物是否能够输运到中国海域.在不考虑背景场浓度的情况下,福岛泄漏的核放射性物质在泄漏后4年能基本侵入整个中国海区,并且在10年内布满整个北太平洋区域,最大值区在北美的西岸外海.相较而言,将国际原子能的观测资料进行资料同化作为背景场使模拟更接近于观测事实.考虑了背景场的模拟显示,2019年进入东中国海的核放射性物质总量达到峰值.除此之外,还计算了各个海峡核放射性污染物通量及其随时间的变化,发现核放射性污染物主要通过吕宋海峡入侵南中国海;台湾海峡、台湾以东洋面为侵入东中国海的主要通道;核放射性污染物通过托克拉海峡、对马海峡流出东中国海.同时计算表明在未考虑径流的情况下,中国东部沿海地区的核放射性污染物浓度有着明显的季节特征,华南沿海冬春核污染物浓度高于夏秋两季,而华东沿海则相反.

An earthquake and the subsequent tsunami on March 11,2011,triggered a chain of disastrous nuclear leaks in Fukushima,Japan. In this study,the Regional Ocean Modeling System（ ROMS） is used to simulate the oceanic circulation and the resulting radioactive concentration distribution and variation in North Pacific and the China Seas. We have found,after a series of experiments,that in the absence of the background concentration,radionuclides begin to enter the China Seas on a large scale four years after the accident,and that in 10 years they will appear everywhere in North Pacific,with the maximum near the western coast of the United States. The simulation with background concentration assimilated（ data from International Atomic Energy Agency） reveals that the total amount of the radioactive material in the East China Sea will reach maxmum in 2019. We have computed the fluxes through all the waterways to these seas,and found that Luzon Strait,Taiwan Strait and the east region of Taiwan are the main entrances for theradionuclides,which spread into East China Sea through Tokara Strait and Tsushima Strait. It is shown that the radionuclide concentration along the China coast may vary in season. Generally,it is high in winter and spring,and low in summer and autumn along the southern China coast,while the trend is reversed along the eastern coast.