SENSITIVITY STUDY OF THE ONLINE-COUPLE MODEL TO DIFFERENT METEOROLOGY BASED ON THE CS-137 TRANSPORT IN THE FUKUSHIMA ACCIDENT

抄録

In the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, a large volume of 137Cs was discharged and broadly transported by the atmosphere, which left long-term ground radioactivity deposition in Japan. The wet deposition process substantially affected the spatiotemporal distribution of both atmospheric and deposited 137Cs concentrations in the FDNPP accident. Numerous efforts have been devoted to understanding the wet deposition following the FDNPP accident and to improving the modelling. However, accurately modelling the wet deposition remains a challenge because of the nonuniformities and uncertainties in the meteorological fields, source terms, modeling, and parameterization. Furthermore, the rough resolution of the meteorological fields might limit a detailed investigation of model behavior at the local scale. In this paper, a meteorology input with a 1 km resolution is applied to study the model sensitivity. The in-cloud (Roselle) and below-cloud (Baklanov) schemes, which both perform well in the 3 km model intercomparison study, were integrated into the WRF-Chem model. A detailed evaluation is performed based on the cumulus deposition and concentration during several plume events to provide a clearer insight into different model performances under various resolutions of the meteorological fields.