Mendo Island Journal — Timely. Useful. Sometimes Cranky.

Study shows Fukushima nuclear pollution becoming MORE concentrated in Pacific as it nears U.S. West Coast — Plume travels a nearly straight line to America — Appears to stay together with little dispersion (MODEL)

In Around the web on August 20, 2013 at 8:00 am

f

From ENE NEWS

Title: An ensemble estimation of impact times and strength of Fukushima nuclear pollution to the east coast of China and the west coast of America
Source: Science China Earth Sciences; Volume 56, Issue 8, pp 1447-1451
Authors: GuiJun Han, Wei Li, HongLi Fu, XueFeng Zhang, XiDong Wang, XinRong Wu, LianXin Zhang
Date: August 2013

[...] On the next day of the Japanese earthquake on March 11, 2011, the nuclear reactors in Fukushima Nuclear Power Plants began to explode. The nuclear reactor explosion resulted in a great amount of radioactive matter leaked into the sea neighboring to Fukushima. On March 30, 2011, the Japan Central News Agency reported the monitored radioactive pollutions that were 4000 times higher than the standard level. Whether or not these nuclear pollutants will be transported to the Pacific-neighboring countries through oceanic circulations becomes a world-wide concern. This study focuses on the impact of Fukushima nuclear pollutants on the east coast of China and the west coast of America through oceanic surface currents. [...]

In the study. the greatest uncertainty is the time scale by which the nuclear pollutants are transported to reach the east coast of China through the surface drifting buoys following the subtropical circulation. From one surface drifting buoy, the estimated time is 1.6 years whereas from 7608 nuclear pollutant particulate tracers, the estimated time is 3.6 years. For other two subgroups of drifting paths, the uncertainty of the transport times is relatively small. The time scale of the nuclear pollutants reaching the west coast of America is 3.2 years if it is estimated using the surface drifting buoys and 3.9 years if it is estimated using the nuclear pollutant particulate tracers. The time scale of the nuclear pollutants reaching the east coast of China in the west of Pacific is 1.3 years if 1 is estimated from the surface drifting buoys and 1.8 years if it is estimated from the nuclear pollutant particulate tracers. [...]

The half life of cesium-137 is so long that it produces more damage to human. Figure 4 gives the examples of the distribution of the impact strength of Cesium-137 at year 1.5 (panel (a)), year 3.5 (panel (b)), and year 4 (panel (c)). From Figure 4, we can see that due to the local eddy role, starting from 1% at 1.5-year. of the initial level at the originating area of Fukushima nuclear pollution, the impact strength of Cesium-137 in the South China Sea continuously increases up to 3% by 4 years. It is worth noting that due to the current near the shore cannot be well reconstructed by the global ocean reanalysis, some nuclear pollutant particulate tracers may come to rest in near shore area, which may result in additional uncertainty in the estimation of the impact strength. For the west coast area of America, the major transport mechanism of nuclear pollutants is the Kuroshio-extension currents. Thus, after four years, the impact strength of Cesium-137 is as high as 4%. [...]

Estimated results show that while the tracers take about four years to reach the west coast of USA. there are two types of tracers to carry out Fukushima nuclear pollutants to reach the east coast of China, corresponding to 1.5-year recirculation gyre transport and 3.5-year subtropical circulation transport. The impact strength distributions at these time scales are given according to the variation of relative number concentration with time combined with the decaying rate of radioactive element. Results show that due to local eddy role, starting from 1% at 1.5-year, of the initial level, the impact strength of Cesium-137 in the South China Sea continuously increases  nt Irk ill I.5-year, of the initial level, the impact strength of Cesium-177 in the South China Sea continuously increases up to 3% by four years. Since the major transport mechanism of nuclear pollutants for the west coast of America is the Kuroshio-extension currents, after four years, the impact strength of Cesium-137 in the west coast area of America is as high as 4%.

View the study online here
~~

Follow

Get every new post delivered to your Inbox.

Join 4,516 other followers