在本研究中我們將探討若干與同化都卜勒雷達資料以改進短期數值天氣預報相關的科學議題，我們準備使用的資料同化方法為系集卡曼濾波器。主要的研究目標在建立一套適合台灣的0-6小時定量降水預報的方案。在本兩年期計畫中吾人預計要完成的工作項目為評估在不同的條件下，使用系集卡曼濾波器同化雷達資料後，對模式預報的影響。這些條件包括：雷達與分析區域的相對位置、雷達資料的觀測誤差、不完整的資料覆蓋、雷達掃描策略、最佳的同化窗口、以及同化氣象變數的種類等。第二年的計畫內容為使用2008年西南氣流實驗當中的模擬個案，來測試系集卡曼濾波器對於短期定量降水預報的改善，而資料可以是在中，由NCAR S-POL、TEAM-R、氣象局七股雷達或墾丁雷達所觀測的劇烈降水系統。In this research we will explore several scientific issues related to short-term numerical weather prediction using Ensemble Kalman Filter (EnKF) to assimilate Doppler radar data into a numerical model. The primary purpose is to establish a 0-6 hr QPF algorithm suitable for Taiwan’s geographic characteristics. The research topic we would like to accomplish in this 2-year project is to study the performance of EnKF under different scenarios, such as the number of ensembles, radar location relative to the analysis domain, observations and background field errors covariances, incomplete data coverage, optimal assimilation window, and so on. In the second year the plan will test EnKF with simulated data targeting the cases collected during TIMREX/SOWMEX by NCAR S-POL, TEAM-R, RCCG or GCKT. The focus of these case studies will be the improvement of the short-term quantitative precipitation forecast (QPF). 研究期間 : 9808 ~ 9907
