本文應用標準化降水蒸發散指數到臺灣百年降水及温度記錄測站，探索超越聖嬰時間尺度時剩/缺水量隨時空而異的區域型態。轉動主成份分析鑑定出三型。以西部平原為主的西部型有 1960 年代後全島變乾的一致性轉折。侷促在北部海岸的北部型有 1970 年代中期後變溼的轉折。兩轉折都扣合温度距平由負變正的時間。出現在花東縱谷的東南型 1960 年代後變乾的同時，藏有相對明顯的多年代，主要反應降雨的乾溼交替變化。類似西部型，變乾傾向則來自上升的温度。
用全球環境資料進行各型態的遙相關分析結果顯示(1)變乾訊號實為亞非洲際尺度的區域印記；(2)該印記反應暖化時熱帶變寬和風暴路徑北移；(3) 1970 年以前較乾的北部型歸因於區域哈德雷環流變弱時，較強（弱）的西南（東北）季風。
濾掉聖嬰後，南北半球分佈不對稱的陸塊對大尺度環流的影響和其對水文平衡之衝擊，被彰顯在因暖化而增強的水文循環。分析南半球遙相關特徵後，我們提出一個概念模型解釋熱帶初始變異如何被維持。一個連結熱帶水汽輻合，平流層經向環流，中緯度行星波擾動的正迴饋圈能解釋何以政府間因應氣候變化專門委員會(Intergovernmental Panel on Climate Change, IPCC)出版的第 4 次氣候變遷評估報告傾向低估暖化脚步。

In this study, we apply a standardized precipitation evapotranspiration index to the centennial-long station rainfall and temperature records in Taiwan to explore the spatiotemporal-varying regional patterns of water abundance/shortage beyond the ENSO timescale. Three regional patterns are identified by the rotated principal component analysis: the western, northern, and southeastern ones. Primarily occurred in the western plains, western pattern has an island-wide wet-to-dry turnabout in early 1960s. Limited to the northern coastal regions, the northern pattern shows a contrasted dry-to-wet turnabout in the mid-1970s. Nevertheless, both are timely locked with the appearance of positive temperature anomalies afterwards. The southeastern pattern, evident in the Hua-Dong valley, shows a comparatively multidecadal wet-and-dry alternation embedded in an overwhelming drying after 1960s. Such an alternation is vastly shaped up by the flip-flop impetus of rainfall record, but the drying trend is attributed to the climbing temperature similar to the scene in the western plains.
We then appraise the global teleconnectivity associated with the identified regional patterns on the basis of a comprehensive suite of environmental datasets. The results reveal that (1) the drying tendency in the western and southeastern patterns is a local fingerprint reflecting the continental-scale dryness in African and Asian landmass; (2) when our world is warming, the signal of (1) corresponds to the widening of tropical belt and poleward shifting of storm tracks in both hemispheres; (3) the drier condition of the northern pattern before 1970s can be attributed to a weaker regional Hadley cell signifying the intermittent pulse of stronger (weaker) southwesterly (northeasterly) monsoons, and vice versa after 1970s.
By sifting out ENSO, the influences of asymmetric setting of landmass in both hemispheres on the large-scale circulations thereby the consequences in the long-term water balance stand out when the hydrological cycle is enhanced in a warming world. An extensive analysis on the teleconnection features seen in the southern hemisphere leads us to propose a conceptual model exploring how the tropical initial variability is maintained. It describes a positive feedback loop linking the enhanced tropical moisture convergences, strengthened stratospheric meridional circulation, and increased mid-latitudinal planetary wave disturbances, as a candidate explain why the IPCC could underestimate the warming pace.