Applicability of four types of meteorological data to Fukushima nuclear accident 137Cs simulations

The local-scale atmospheric transport of 137Cs following the Fukushima accident was investigated using ensemble modelling based on four different meteorological inputs (FNL reanalysis data, ERA-Interim reanalysis data, GFS analysis and forecast data, and MEA field meteorological observations data). Two different types of atmospheric transport model were used, i.e., regional-scale meteorological model WRF and Lagrangian particle dispersion model FLEXPART. The influence of different meteorological data was evaluated based on the monitoring data from two monitoring stations in Futaba and Naraha. The simulations showed that FLEXPART successfully reproduced most of the peaks at both stations using all four types of meteorological data (average FAC10 of Futaba:0.57; average FAC10 of Naraha:0.58). The simulations using ERA-Interim and MEA reproduce more peak observations and achieve more satisfactory statistical metrics than the others. The simulated spatial 137Cs distribution using four meteorological data were slightly different. The results of ERA-Interim and MEA showed a wider range of plumes, better reproducing the observations. Therefore, ERA-Interim and MEA are recommended for simulating the atmospheric 137Cs transport following the Fukushima nuclear accident at local scale. © 2024 Chinese Society for Environmental Sciences. All rights reserved.