卷雲是出現在高對流層的冰雲，由於分佈範圍很廣，所以在全球 的天氣系統和輻射平衡上扮演了重要的角色。Cloud?Aerosol Lidar and Infrared Pathfinder Satellite Observation(CALIPSO) 衛星的發射提 供了我們一個從太空用光達觀測地球大氣垂直結構的方式，對於了解 全球的卷雲分佈上有很大的幫助。本研究利用CALIPSO 提供的2008 年12 月到2012 年2 月雲層資料進行統計分析，結果顯示卷雲發生機 率在赤道地區最高，並且被卷雲覆蓋的範圍有季節性的變化，6-8 月 的分佈偏向北半球、12-2 月偏向南半球，在北半球的夏季卷雲主要集 中於亞洲夏季季風區。分析台灣地區(北緯20 度至30 度，東經115 度至125 度)的卷雲發生機率與利用Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT)模式進行氣流的逆軌跡追蹤，發現在 6、7 月份的高空氣流大部分來自西方，且傳輸路徑會行經亞洲夏季 季風區，8 月則來自東亞夏季季風區，可知台灣地區夏季卷雲發生機 率高的主要成因與夏季季風區之間有密切的關係。 Cirrus clouds are ice clouds of the upper troposphere and spreading around the world. They are one of the important factors, which play critical roles in the Earth‘s energy balance by reflecting, absorbing and transmitting the solar radiation. Cloud ? Aerosol Lidar and Infrared Pathfinder Satellite Observation(CALIPSO) provides us a chance to observe the vertical structure of atmosphere by using lidar from space. It is really helpful to study cirrus clouds around earth. Using a 3-year data from CALIPSO, the occurrence frequency, layer base altitude, and optical depth of cirrus clouds are studied. The investigation of cirrus clouds shows the maximum occurrence frequency near the tropics. The results show large latitude movement of cirrus clouds cover with the seasonal distribution. In the north hemisphere, the maximum of cirrus clouds frequency are around the Asia Summer Monsoon from June to August. The frequency of cirrus cloud occurrence in Taiwan(20-30°N, 115-125°E) are higher in summer, and the backward trajectories of air flow over Taiwan by using Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT), which can trace back to Asia Summer Monsoon and East Asia Summer Monsoon. Thus, cirrus clouds could be transported from Summer Monsoon to Taiwan.
