Hydroclimatic variability in Santiago (Chile) since the 16th century
Hydroclimatic variability in Santiago (Chile) since the 16th century
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DOI：
10.1002/joc.6828
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发表时间：
2020-09
期刊：
影响因子：
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通讯作者：
R. Serrano‐Notivoli;E. Tejedor;P. Sarricolea;O. Meseguer‐Ruiz;M. Vuille;Magdalena Fuentealba;M. Luis
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文献类型：
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作者：
R. Serrano‐Notivoli;E. Tejedor;P. Sarricolea;O. Meseguer‐Ruiz;M. Vuille;Magdalena Fuentealba;M. Luis
利用新的481年(1536-2016年CE)树轮重建8月份标准化降水蒸散指数(SPEI)，结合之前14个月的水文气候条件，分析了智利圣地亚哥的长期水文气候变异性。结果表明，20世纪末21世纪初极端干旱事件发生频率较高，17-18世纪极端潮湿事件发生频率较高。20世纪中叶是该区域水文气候历史的一个转折点，其中包括一些重大变化：(A)年际变率增加；(B)潮湿事件变得不那么强烈；(C)极端干旱事件变得更加频繁；(D)确定了整个时期最强烈的干旱事件，恰逢所谓的大干旱(2006-2016年)。考虑到不同的多年尺度，在月尺度上对重建的SPI与3个气候指数(PDO、SOI和Niño3.4)进行了相关分析。分析表明，SPI与PDO、Niño3.4呈正相关，与SOI呈负相关，对水文气候变率的影响程度不同。总体而言，最显著的相关性是在多年的时间尺度上(>；7年)发现的。结果有助于在长期背景下更好地理解当前的水文气候变化(巨变)。
The long‐term hydroclimatic variability in Santiago (Chile) was analysed by means of a new 481‐year (1536–2016 CE) tree‐ring reconstruction of the Standardized Precipitation Evapotranspiration Index (SPEI) of August, integrating the hydroclimatic conditions during the preceding 14 months. Results show a high frequency of extreme drought events in the late 20th and early 21st centuries, while the frequency of extreme wet events was higher in the 17th–18th centuries. The mid‐20th century represents a breaking point for the hydroclimatic history in the region, including some significant changes: (a) the interannual variability increased; (b) the wet events became less intense; (c) the extreme dry events became more frequent; and (d) the most intense dry event of the entire period was identified, coinciding with the so‐called Megadrought (2006–2016). A correlation analysis between the reconstructed SPEI and three climate indices (PDO, SOI and Niño3.4) was performed at monthly scale, considering different multi‐annual aggregations. The analysis shows diverse impacts on the hydroclimatic variability, with positive correlations between SPEI and PDO as well as Niño3.4, and negative correlations between SPEI and SOI. The most significant correlations were, overall, found at multi‐annual time scales (>7 years). Results help to better understand the current hydroclimatic changes (Megadrought) in a long‐term context.