Genki Katata

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The Fukushima Daiichi nuclear power plant accident in Japan triggered by a magnitude 9.0 earthquake and resulting tsunami on March 11, 2011 caused the month-long discharge of radioactive materials into the atmosphere. It is urgent to assess the radiological dose to the public resulting from this release, using both environmental monitoring data and computer(More)
Regional-scale atmospheric dispersion simulations were carried out to verify the source term of (131)I and (137)Cs estimated in our previous studies, and to analyze the atmospheric dispersion and surface deposition during the Fukushima Dai-ichi Nuclear Power Plant accident. The accuracy of the source term was evaluated by comparing the simulation results(More)
To understand how the high dose rate zones were created during the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident on March 2011, the atmospheric dispersion of radionuclides during the period from 15 to 17 March was reproduced by using a computer-based nuclear emergency response system, WSPEEDI-II. With use of limited environmental monitoring data,(More)
The atmospheric release of (131)I and (137)Cs in the early phase of the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident from March 12 to 14, 2011 was estimated by combining environmental data with atmospheric dispersion simulations under the assumption of a unit release rate (1 Bq h(-1)). For the simulation, WSPEEDI-II computer-based nuclear(More)
Tropospheric ozone concentrations have increased by 60-100% in the Northern Hemisphere since the 19(th) century. The phytotoxic nature of ozone can impair forest productivity. In addition, ozone affects stomatal functions, by both favoring stomatal closure and impairing stomatal control. Ozone-induced stomatal sluggishness, i.e., a delay in stomatal(More)
A one-dimensional soil model has been developed to better predict heat and water exchanges in arid and semiarid regions. New schemes to calculate evaporation and adsorption in the soil were incorporated in the model. High performance of the model was confirmed by comparison of predicted surface fluxes, soil temperature, and volumetric soil water content(More)
In order to investigate the transport of radionuclides in the terrestrial biosphere we have developed a one-dimensional numerical model named SOLVEG that predicts the transfer of water, heat, and gaseous and particulate matters in the atmosphere-vegetation-soil system. SOLVEG represents the atmosphere, the soil, and the vegetation as an aggregation of(More)
The Fukushima Daiichi nuclear power reactor units that generated large amounts of airborne discharges during the period of March 12-21, 2011 were identified individually by analyzing the combination of measured (134)Cs/(137)Cs depositions on ground surfaces and atmospheric transport and deposition simulations. Because the values of (134)Cs/(137)Cs are(More)
Abstract It is urgent to assess the radiological dose to the public resulting from the month-long discharge of radioactive materials into the atmosphere from the Fukushima Daiichi Nuclear Power Plant accident in Japan in March 2011. To do this task, computer simulations on the dispersion of radioactive materials in the environment are useful. However, the(More)
Recent progress in modeling fogwater (and low cloud water) deposition over terrestrial ecosystems during fogwater droplet interception by vegetative surfaces is reviewed. Several types of models and parameterizations for fogwater deposition are discussed with comparing assumptions, input parameter requirements, and modeled processes. The relationships among(More)