Blog Archive

Tuesday, 2 September 2014

Ocean Tracer Simulations


Ocean modeling used for simulations advection of tracers and spreading of pollutants, including radionuclieds, in the world ocean.

The world ocean plays an important role in the Earth’s climate system due to its enormous capacity to absorb, store and transport heat. Ocean ventilation associated with water mass formation is one of the most important properties in understanding the role of oceans in climate. Ocean tracers can be used to understand the ocean ventilation and to validate the Ocean General Circulation Model. Passive tracers (e-g. CFCs) have been used at Nansen Center to validate and constrain Miami Isopycnic Coordinate Ocean Model (MICOM). In addition, the developed ocean model system is used for ocean tracer simulations including the propagation of marine pollution such as radionuclides.

Ocean spreading of radioactivity from the Fukushima nuclear plant in Japan
The extraordinary earthquake that generated an extreme tsunami that struck Japan, has led to radioactive leaks into the sea from the Fukushima reactors. Our numerical ocean model has been used to simulate the potential spread of radioactive waste into the sea from Fukushima reactors and among other things the spreading towards China. This ocean modeling system has been developed over the past ten years and has previously been used for the modeling of radioactive dispersal from Sellafield in the UK and from sources in the Russian Arctic sector both at present and in the future under different scenarios.

With the simulation from Fukushima reactors, we assume a constant leak throughout one year from March 2011. Even with only one month of leakage the spreading patterns will in principle be the same, but over a smaller area. The results show that the maximum concentration propagates eastward in the Pacific toward the United States during a 7-year period while the total concentration drops to 1-2% of the source concentration (100%) after 5 years.

http://www.nersc.no/data/ocean-tracer-simulations
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