Almost half of the tributaries of the Amazon River originate in the tropical Andes and support large populations in mountain regions and downstream areas. However, it is difficult to assess hydroclimatic conditions or to evaluate future scenarios due to the scarcity of long, high‐quality instrumental records. Data from the Global Precipitation Climatology Project (GPCP) provide a complete record since 1979 and offer a good representation of rainfall over the tropical Andes. Longer records are needed to improve our understanding of rainfall variability and summer monsoon behavior at various scales. We developed the first annually resolved precipitation reconstruction for the tropical Andes in Peru, based on tree‐ring chronologies of Cedrela and Juglans species. The annual (November–October) reconstruction extends the short instrumental records back to 1817, explaining 68% of the total variance of precipitation over the 1979–2007 calibration period. The reconstruction reveals the well‐documented influence of El Niño‐Southern Oscillation (ENSO) on Amazon Rainfall at interannual scales (~19% of total variance) and significant multidecadal variability with alternating periods of about 40 years (~13% of rainfall variability) related to the Atlantic Multidecadal Oscillation (AMO). Both oscillatory modes can explain dry and humid periods observed within the reconstruction and are likely associated with the negative trends of rainfall in the short instrumental records and the increased drought recurrence in recent decades. Our results show that montane tropical tree rings can be used to reconstruct precipitation with exceptionally high fidelity, characterize the interannual to multidecadal variability, and identify remote forcings in the hydroclimate over the Andean Amazon Basin of Peru.

中文翻译：

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从秘鲁亚马逊安第斯山脉的树环记录重建两个世纪的水文气候变异性

亚马孙河的支流几乎有一半来自热带安第斯山脉，为山区和下游地区的大量人口提供了支持。但是，由于长期缺乏高质量的仪器记录，因此难以评估水文气候条件或评估未来情景。自1979年以来，全球降水气候学项目（GPCP）的数据提供了完整的记录，并很好地表示了热带安第斯山脉的降雨。需要更长的记录来增进我们对各种尺度的降雨变化和夏季季风行为的了解。我们根据塞德雷拉和胡桃树的树轮年表，为秘鲁的热带安第斯山脉开发了第一个年度解析的降水重建方案种类。年度（11月至10月）重建将短的仪器记录扩展到1817年，解释了1979-2007年校准期间降水总量变化的68％。重建结果显示，厄尔尼诺-南方涛动（ENSO）对亚马逊降水的年际尺度（占总方差的〜19％）和显着的多年代际变化（约40年交替）（降水变化的〜13％）的影响已得到充分证明。与大西洋多年代际振荡（AMO）有关。两种振荡模式都可以解释在重建过程中观测到的干旱和潮湿时期，并且可能与短的仪器记录中降雨的负面趋势以及近几十年来干旱复发的增加有关。