Modeling the dispersal at sea of Fukushima emissions -------------------------------------------------------------------------------------------------------------------------- No sooner had the news of radioactivity leakage from the Fukushima nuclear plant broken, than French researchers were approached by the International Atomic Energy Agency to set up a forecasting system for the dispersal at sea of the radionuclides emitted along Japan’s Pacific coast. From March to September 2011, they used a realistic simulation model of the coastal ocean to perform daily simulations of the dispersal of radioactive emissions from the plant. To do this, they adapted their model’s calculation grid to the geographical, bathymetric and oceanic features of the Japanese coast, and collected oceanic and meteorological data at frequent intervals. They also adjusted the fluxes of radioactive water from the nuclear power plant used in the model so as to ensure the best possible reproduction of the cesium-137 concentrations measured in the immediate vicinity of the plant. They found that transport mainly occurs along the coast, alternately northwards and southwards. The next steps will concentrate on the long-term need to take account of river inputs produced by leaching from drainage basins, as well as the movement of contaminants through the food chain. 18-20 March 26-28 March 01-03 April Distribution of total ozone content measured by the IASI instrument on board the MetOp satellite, at different periods. Red and yellow areas indicate high ozone concentrations. Ozone loss over North Pole reaches new heights In the spring of 2011, exceptional meteorological conditions led to unprecedented ozone loss over the Arctic. Observations by French researchers, together with computer models, have shown that ozone depletion had reached around 40% by the end of March. The phenomenon was caused by an extremely cold and persistent stratospheric winter, leading to significant ozone destruction, which untypically continued into spring. It is worth noting that the ozone layer acts like IASI Ozone Total Column (DU) LATMOS/ULB a shield that protects life on Earth from harmful ultraviolet solar radiation. 150 200 250 300 350 400 450 500 Parasites improve stability of ecosystems Researchers have shown that the tiny parasitic fungi of phytoplankton improve the stability and resilience of aquatic ecosystems. The scientists modeled trophic activity in Lake Pavin, in the Auvergne region of France, and highlighted the role played by the microscopic fungi they observed. This finding highlights the need to take into account the role of microorganism parasites in the functioning of ecosystems, which are faced with increasing human pressure and the effects of climate change. PLoS One August 2011 A colony of Chlorophyceae infected by parasitic fungi spores (chytrids). 45 2011 A year at CNRS
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