2015-08-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/672909摘要：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、複雜的地形地貌及對流(或熱力)引發的環流皆會顯著影響地形降水的物理過程。臺灣地形複雜，不僅豪雨的發生經常與地形效應密切相關，同時降雨強度與分布受到地形影響甚劇。然而，在這樣獨特的地理環境架構之下，現階段不論國內外，對於其隱含之動力(物理)過程的了解仍相當缺乏。因此，增進臺灣地區地形降水機制的知識，是一項克不容緩的重要議題。 　　本研究計畫主要的科學目的在於藉著分析地形附近的高解析度都卜勒雷達資料與其他各種觀測資料，詳細檢視不同綜觀環境條件下，地形效應對降水分布及強度的影響，以期拓展臺灣地形降水的了解。我們預計針對颱風環境條件及弱綜觀環境條件之地形降水作深入分析探討。在颱風環境影響下，研究議題分為兩類：「颱風地形降水」及「登陸颱風雨帶受地形效應之影響」；在弱綜觀環境下的研究重點為「臺灣東南沿海對流線與地形效應」。另外，對於降水過程的雲物理研究，著重於「地形降水之水滴落速觀測分析」。除了以上的觀測研究分析外，本研究計畫也將發展較理想化的「地形降水估計診斷模式」，並評估其對於臺灣地形降水的掌握能力，以提供未來降水估計研究與降雨預報的參考。<br> Abstract: Recent observational and numerical studies have revealed the complexity of orographic precipitation and a significant gap in our knowledge of its underlying processes. Many factors, such as the variable synoptic environments, orographic geometries, and the influences of convectively/thermodynamically generated circulations, can influence the physical processes of orographic precipitation. For mountainous Taiwan, the occurrence of the torrential rainfall is usually related to the topographic effects. To achieve a better prediction of heavy rainfall in Taiwan, improving understanding of mechanisms of orographic precipitation under different environmental conditions is critically important. 　　In this study, the detailed Doppler radar observations and other available observations collected from the Taiwan area are used to investigate how orographic effects influence the precipitation distribution and intensity in different environmental conditions, in an attempt to explore our knowledge of precipitation processes active over mountains. Two distinct synoptic conditions, the typhoon environment and weak synoptic forcings, will be focused. For the typhoon environment, orographic precipitation and the influence of topography on landfalling tropical cyclone rainbands will be both investigated. For the weakly synoptic environment, the convective lines occurring off the mountainous coast of southeastern Taiwan will be examined. To improve understanding of precipitation processes, the characteristics of the droplet fall speed of orographic precipitation will also be explored. In addition, we will develop and evaluate an idealized diagnostic model of orographic precipitation, and these research results are expected to provide important references to future studies of precipitation estimate and forecasting in the Taiwan area.地形降水地形效應颱風雨帶流線水滴落速地形降水診斷模式orographic precipitationtopographic effectstropical cyclone rainbandsconvective linediagnostic model