臺灣區域豪雨觀測與預報實驗後續研究-同化雙偏極化參數在對流尺度天氣之影響－觀測算符之優化與雲微物理方案測試(總計畫及子計畫三)

By participating the Taiwan-Area Heavy rain Observation and Prediction Experiment (TAHOPE) field campaign, this study evaluates the impact of assimilating dual-polarimetric radar parameters. The performance of numericalmodels in simulating cloud microphysics of severe weather systems is also examined to validate the impact on high impact weather (High Impact weather) of very short-term forecasts. By using the ensemble data assimilation system, this study applies high-resolution numerical weather prediction model (~1km) and high-density observation radar data (1km). In addition to assimilate the radar Doppler wind and reflectivity, the polarimetric parameters, i.e., ZDR and KDP are also assimilated. The cases during the observation experiment are collected and investigated. In first step, it is focused on the establishment of the dual polarization parameter observation operator in the assimilation system, as well as its sensitivity test and optimization. Then, the new analysis field is used to examine the feature and structure of the precipitation system in horizontal and vertical. The performance of the 0-6 h short-term forecasts is verified. Moreover, how to improve the microphysics parameterization scheme through observational data is also one of the goals of this study.