欧州トレーサー実験に対する気象研究所長距離輸送モデルのパフォーマンスとその評価

Abstract

To predict the tracer cloud evolution in the European Tracer Experiment, two numerical simulation runs of air tracer dispersion are performed by using different meteorological input data. There are the global objective analyses, by the European Centre for Medium-Range Weather Forecast (ECMWF), and by the Japan Meteorological Agency (JMA). The simulated results are compared with each other, and evaluated statistically based on measured tracer concentration at specific sampling sites. The results of the statistical evaluation show that the predicted tracer cloud evolution, using the JMA analysis data, indicates a slightly better statistical score in the global and space dependent analyses, than the result by the ECMWF. The scores in the time dependent analysis show deferent values at every specific sampling sites, however, the averaged scores are slightly better for results by the ECMWF. It is difficult to discriminate synthetic superiority, and inferiority between both runs. It is inferred that the difference between both wind fields leads to different cloud evolution. The simulated tracer cloud evolution showed relatively good correspondence with measurements. Further reference on the appropriate deposition velocity, and inclusion of precipitation process, are needed to get better correspondence with measurements.