配合2020年國際觀測實驗中之臺灣區域豪雨觀測與預報實驗計畫，本研究將蒐集觀測實驗期間之個案，實際評估地面掃描式儀器( 包含S與Ka 波段雷達 )所反演之濕度場資訊，檢視其在對流尺度天氣系統極短期預報之影響。根據先前利用觀測系統模擬實驗( OSSE )之結果，第二階段研究將著重於綜觀尺度作用下所引發之劇烈天氣系統( 颱風或梅雨鋒面系統 )，採用高解析度數值天氣預報模式，結合先前研發之系集資料同化系統，除了同化雷達都卜勒風場與回波之外，進一步將美國大氣科學研究中心 S-PolKa 雷達所提供之折射指數與雙波段反演之水氣資訊進行同化。預計蒐集野外實驗當中密集觀測期間 2-3 個個案進行分析與討論，了解影響台灣之劇烈降水系統，若提供濕度場資訊進行同化後之效益。檢視對流天氣系統其分析場在水平與垂直方向上結構，進一步檢驗根據此分析場進行0-6小時極短期預報之能力評估。 ;Collocate with the Taiwan-Area Heavy rain Observation and Prediction experiment (TAHOPE) which is an international field experiment in 2020, this study plans to collect real cases during the field experiment and assimilate the humidity field information retrieved by scanning instruments (including S and Ka band radars), then examine its impact of very short-term forecasts on convective-scale weather systems. Based on the results of previous observation system simulation experiments (OSSE), the second phase of the study focuses on the severe weather system triggered by synoptic forcing (e.g. typhoon or Meiyu frontal system). The ensemble data assimilation system developed by National Central University is used with the high-resolution WRF model. In addition to assimilating radar Doppler wind and reflectivity fields, water vapor information provided and retrieved by NCAR S-PolKa radar is assimilated. With 2-3 cases during the intensive observation period in the field experiment, both horizontal and vertical structures of the convective weather system can be examined after assimilating radar observations. Moreover, very short-term forecast (0-6 h) launched by the optimal analysis fields is further investigated and evaluated.
