要準確預測地形附近的降水情形，最大的挑戰就是如何評估地形效應對於降水分佈及強度的影響。近年來的觀測與數值模擬研究已經顯示地形降水的複雜度，以及突顯我們對它瞭解的不足。綜觀環境的多樣化、地形地貌及對流（或熱力）引發的環流皆會顯著改變地形降水的物理過程。而山區附近詳細觀測資料的缺乏也是長久以來我們無法深入探討地形降水的主因。本研究計畫主要的科學目的在於藉著地形附近所收集的高解析度都卜勒雷達資料(包括台灣地區雷達資料與其他中緯度地區實驗計畫所收集的雷達資料)針對不同環境條件來廣泛檢視地形效應對降水分佈及強度的影響，以期增進我們對於地形降水過程的瞭解。而研究方向將同時著重地形上游效應(Upstream Effects)、地形斜坡強迫(Upslope Forcings)與局部環流的探討。
One of the most important challenges of predicting rainfall over regions adjacent to mountains is properly assessing the significance of the orography to the precipitation distribution and intensity. Recent observational and numerical studies have revealed the complexity of orographic precipitation and a significant gap in our knowledge of it. Many factors, such as the varied synoptic environment, orographic geometries and the influences of convectively (thermodynamically) generated circulations, can alter the physical processes of orographic precipitation and increase their complexity. The lack of detailed observations over mountains often cause difficulties in documenting these phenomena. In this study, detailed ground-based and airborne Doppler radar observations collected from the Taiwan area and recent mesoscale field experiments are used to investigate how orographic effects influence the precipitation distribution and intensity in different environmental conditions, in an attempt to improve our understanding of precipitation processes over mountains. Study on the upstream effect, the upslope forcings, and the local circulations will be particularly focused.
