NOAA/WDS Paleoclimatology - Li - Maxiong Valley - ABFO - ITRDB CHIN075

Rapid warming has been observed in the high-altitude areas around the globe, but the implications on moisture change are not fully understood. Here we use tree-rings to reveal common moisture change on the southeastern Tibetan Plateau (TP) during the past five centuries, and show that regional moisture change in late spring to early summer (April-June) is closely related to large-scale temperature anomaly over the TP, with increased moisture coincident with periods of high temperature. The most recent pluvial during the 1990s-2000s is likely the wettest for the past five centuries, which coincides with the warmest period on the TP during the past millennium. Dynamic analysis reveals that vertical air convection is enhanced in response to anomalous TP surface warming, leading to an increase in lower-tropospheric humidity and effective precipitation over the southeastern TP. The coherent warm-wet relationship identified in both tree-rings and dynamic analysis implies a generally wetter condition on the southeastern TP under future warming.

全球高海拔区域均已观测到快速增温现象，但其对水分变化的影响机制尚未完全阐明。本研究利用树木年轮重建了过去5个世纪以来青藏高原东南部（Tibetan Plateau, TP）的区域水分变化序列，结果表明，该区域晚春至初夏（4-6月）的水分变化与青藏高原大范围气温异常显著相关，且湿润时段与高温时段高度重合。1990年代至2000年代的近期湿润期很可能是过去5个世纪以来最为湿润的时段，这与过去千年间青藏高原最为温暖的时期完全吻合。动力学分析结果显示，青藏高原地表异常增温会引发垂直对流活动增强，进而导致青藏高原东南部对流层低层湿度提升与有效降水量增加。本研究通过树木年轮与动力学分析共同证实的暖湿耦合关系，意味着未来全球增温背景下，青藏高原东南部的气候状态将整体更为湿润。