本研究探討使用四維變分方法(Four-Dimensional Variational Doppler Radar Analysis System :VDRAS)來同化都卜勒氣象雷達資料時，對短期數值天氣預報的改善。本計畫之工作目標是將VDRAS 同化系統中的微物理過程，由目前的暖雨(warm rain)過程，延伸到包含冰相的冷雨(cold rain)過程，並經由一系列的數值實驗，以了解加入冷雨過程後，對雷達資料同化和後續模式預報之影響。本計畫最終的目標在於建立一套適合台灣地區地理、氣象條件與觀測能力的短期(0~3小時)定量降水預報方案。 In this research, we will assess the improvement of the short-term numerical weather prediction by assimilating Doppler weather radar data using the four-dimensional Variational Doppler Radar Analysis System (VDRAS). The primary goal is to modify the VDRAS microphysical scheme by extending it from the current warm rain process to include the ice phase, or the so-called cold rain process. Through a series of numerical experiments, it is attempted to study the influence of implementing the cold rain process on the radar data assimilation, as well as the following model forecasts. The ultimate purpose of this research is to construct a short-term (0-3 hr) quantitative precipitation forecast (QPF) algorithm suitable for Taiwan’s geographic and meteorological characteristics and observational capability. 研究期間：9908 ~ 10007
