伴隨鋒面系統的降水現象是導致台灣地區極端降雨事件的來源之一，但同時也是重要的水資源。在過去的研究中顯示，不同季節的鋒面系統與大尺度環境的變化和多重時間尺度的氣候振盪相關。這也代表在氣候變遷情境下，多重時空尺度之大氣環境條件改變，對於台灣地區的鋒面系統出現的頻率或特性都會造成影響。本研究將利用長期之氣候分析資料與客觀分析技術，回溯台灣長期鋒面系統之變化。並使用IPCC第五次評估報告(AR5) 中氣候推估所依據之CMIP5模式推估資料集，分析各種氣候變遷情境下台灣地區鋒面系統發生頻率的變化。同時利用分析的結果，針對各種氣候變遷情境下台灣地區伴隨鋒面系統降雨進行氣候推估。本計劃將分三年的時間完成各項工作。首先我們會回溯長時間之歷史鋒面系統分析，並利用這些資料建立客觀可靠之分析工具。接著，將針對CMIP5模式後報(hindcast)資料中大氣環境特徵與實際大氣的相似性，將CMIP5模式進行群聚分析。最後將利用所開發之工具，以群聚分析之結果作為參考指標，針對各種氣候變遷情境下台灣地區鋒面系統發生頻率的變化與伴隨鋒面系統降雨進行氣候推估。
The frontal precipitation is one of important water resources in Taiwan. However, this type of precipitation also is the major causes of extreme rainfall events and also induced nature disaster. Based on previous study, front system from different season show correlation with large-scale environmental variations and multi-scale climate oscillations. This correlation also implies that the change of the large-scale environmental variations can influence frontal systems frequency or properties in Taiwan under climate change scenarios. In this study, we will use long-term climate numerical reanalysis/hindcast data and objective analyzing tools to reinvestigate the change of the long-term front system in Taiwan. We will apply the CMIP5 model dataset which was used for climate projection in IPCC Fifth Assessment Report (AR5). The final goal is use those data to analyze the frequency of the front system in Taiwan under different climate change scenarios. This project will be divided into three years. We plan to re-analyze the historic data of front system and establish the objective analyzing tool in the first year. The next step is applying the clustering analysis of CMIP5 model to diagnose the difference between CMIP5 models. We will use those tools and results to estimate the frontal precipitation changes/variations under different climate change scenarios
