本研究利用台灣5個百年測站資料與CMIP5模式資料，探討台灣冬季寒潮之過去變遷與未來推估。5個測站資料顯示近100年來的冬季寒潮發生頻率、低溫日數皆呈現顯著減少趨勢，但48小時日最低溫降幅則出現增加趨勢，寒潮持續天數則無明顯趨勢。觀測顯示台灣寒潮發生頻率與西伯利亞高壓以及東亞主槽的強度呈統計相關，北極振盪與寒潮發生頻率在統計上無明顯相關，但伴隨北極振盪負相位的大尺度環流則有利於極端寒潮事件的發生。CMIP5多模式系集平均結果顯示，2組暖化情境下(RCP4.5、RCP8.5)寒潮的發生頻率、低溫日數以及寒潮持續日數都呈現顯著減少趨勢，暖化導致台灣冬季溫度提升，日低溫不易跨過寒潮門檻是主要原因之一。相較於現今氣候態，西伯利亞高壓強度與範圍在暖化情境下無明顯改變，東亞主槽則呈減弱趨勢，導致東北季風與伴隨冷平流減弱，不利台灣發生寒潮事件。現今氣候態下，台灣寒潮發生頻率與西伯利亞高壓的統計相關性偏低；寒潮發生頻率與東亞主槽強度具統計相關；暖化情境下，台灣寒潮頻率與大尺度環流指標的相關性普遍下降，去除暖化增溫趨勢的影響之後，寒潮發生頻率與東亞主槽強度的相關性在21世紀末明顯提升，顯示暖化導致的熱力作用可能是造成寒潮發生頻率與大尺度環流變化關係性減弱的關鍵因素。雖然暖化情境下，台灣寒潮發生頻率減少，但48小時日最低溫降幅不減反增，如何預防溫度大幅驟降是未來防寒災需特別留意的事項。

The cold surge frequency in Taiwan in present climate and future projection under global warming was investigated by using five long-term (more than 100 years) station’s data of the Central Weather Bureau and the Coupled Model Intercomparison Project Phase 5 (CMIP5) simulations, respectively. The long-term observations reveal that the cold surge frequency and cold days in Taiwan shows a significant decreasing trend; conversely, the 48-hour minimum temperature drop rate exhibits a significant increasing trend. Regression indicates that the cold surge frequency in Taiwan was significantly correlated with Siberian high and East Asia trough. No significant statistical relationship was detected between the Arctic Oscillation and cold surge frequency even though the Arctic Oscillation associated large-scale circulation provides a favorable large-scale environment for the occurrence of extreme cold surge. The CMIP5 multi-model ensemble reveals that the cold surge frequency, cold days and the duration of cold surge in Taiwan all show significant long-term decreasing trend in the 21th century in the warming scenarios of RCP4.5 and RCP8.5. CMIP5 simulations yield that the strength of Siberian high was nearly unchanged whereas the East Asia trough exhibited significant long-term decreasing trend in the future projection. The decrease of cold surge frequency in future was primarily resulted from the weakening of East Asia trough that decreases substantially the northeasterly prevailing wind and the cold air temperature advection. However, the significant relationship between the East Asia trough and the cold surge frequency in Taiwan decreases remarkably in the future due to the thermal effect induced by warming trend. Notably, the 48-hour minimum temperature drop rate shows remarkable increase in the future. That indicates that the warning of dramatically temperature drop will be an important issue in preventing the cold surge induced disaster in the warming climate.