對於研究氣膠的吸濕性和成雲的過程，利用拉曼光達來同步地觀測大氣中的水汽和氣膠是相當具有吸引力的方式。本論文描述第一次在台灣中壢地區同步操作兩套光達系統，分別為偏振光達及拉曼光達來研究低對流層中的氣膠和水汽，並討論水汽對氣膠之微物理性質的影響。 分析其觀測的結果幫助我們了解不同時間在低對流層中濕度的高度分佈。除了研究氣膠的吸濕性之外，我們也利用拉曼光達技術分別決定出氣膠的消光係數及背向散射係數的垂直剖面圖，進而計算出消光背向散射比(lidar ratio)。 由同步觀測之結果發現在3/14之個案中水汽與氣膠消偏振比值隨時間之變化呈現負相關，證實了氣膠與水汽間的交互作用，即氣膠吸濕性。並藉由氣膠消偏振比值與lidar ratio值的差異可說明由不同來源的氣膠有不同的光學特性。中國北部而來之氣膠(沙塵)其消偏振比值(>0.15)相較於中國中南部、東南亞或台灣海峽附近等地而來之氣膠消偏振比值（0.06?0.1）有顯著的差異，且中國北方來之氣膠和沿岸而來之氣膠比起由中國南方來的氣膠有相對較小的lidar ratio值。 The unique capability of the Raman lidar to simultaneously observe water vapor and aerosols makes the technique very attractive for studying the hygroscopic aerosols and the conditions under which clouds form. This thesis describe two lidar sytems viz Depolar and Raman lidar system simultaneously for the first time at Chung-Li, Taiwan to study aerosols and water vapor in the lower troposphere and discuss the impact of water vapor on the microphysical properties of aerosols. Analysis of the results help us to understand the small scales perturbation of humidity in the lower troposphere over different time scales. In addition, the studies of hygroscopic growth of aerosols, the lidar ratio profile of aerosols which is computed by using Raman lidar technique for determining independently the aerosols extinction and backscatter coefficients vertical profiles have been also discussed.
