Potential utility of tree ring delta O-18 series for reconstructing precipitation records from the lower reaches of the Yangtze River, southeast China
Potential utility of tree ring delta O-18 series for reconstructing precipitation records from the lower reaches of the Yangtze River, southeast China
复制标题
树轮三角洲O-18系列重建中国东南部长江下游降水记录的潜在用途
DOI：
10.1002/2015jd023610
复制
发表时间：
2016
影响因子：
4.4
通讯作者：
Sano Masaki
中科院分区：
文献类型：
--
作者：
Xu Chenxi;Ge Junyi;Nakatsuka Takeshi;Yi Liang;Zheng Huaizhou;Sano Masaki
本文研究了长江下游台湾松林年轮纤维素中氧同位素组成（δ18O）的年际和年内变化，以探讨其在1855-2013年降水重建中的潜在应用价值。年轮纤维素δ18O的年际变化表现出明显的年循环特征，δ18O在年轮边缘附近生长早期达到最大值，而在年轮中后期δ18O最小。树木年轮δ18O的季节分布受8 ~ 10月台风的影响。测定了幼树和老树的年轮纤维素δ18O，以检验幼龄效应。结果表明，老树和幼树δ18O的平均值和长期变化趋势无显著差异。响应分析表明，5 - 10月树木年轮δ18O与降水量和相对湿度呈显著相关，δ18O年代学占1951 - 2013年5 - 10月降水量实际变化的37.4%。基于树木年轮δ18O‐的重建降水所揭示的极端干湿年份也与文献记录的实际局部干旱和洪水事件相对应。重建降水与热带太平洋中部海表温度呈显著相关，表明El Niño-Southern涛动（ENSO）对长江下游5 - 10月降水有影响。此外，1920 - 1940年ENSO与降水的关系减弱，1920 - 1940年ENSO的低方差可能导致ENSO对中国东南部降水的影响减弱。
In this study, we investigated the interannual and intraannual variabilities in the oxygen isotope composition (δ18O) preserved in the tree ring cellulose ofPinus taiwanensisin the lower reaches of the Yangtze River, southeast China, to explore its potential utility for precipitation reconstruction over the period of 1855–2013. Intraannual variations of tree ring cellulose δ18O show distinct annual cycles that are characterized by δ18O maxima in the early growth near the ring boundary and δ18O minima in the middle and late portions of the ring. Seasonal patterns of tree ring δ18O were influenced by August–October typhoons. The tree ring cellulose δ18O was measured in both young and old trees to test for the juvenile effect. The results revealed no significant differences in the mean values and long‐term trends in δ18O in the old and young trees. A response analysis indicated that tree ring δ18O correlated significantly with precipitation and relative humidity between May and October, and the δ18O chronology accounted for 37.4% of the actual variation in the May–October precipitation between 1951 and 2013. The extremely dry and wet years revealed by the tree ring δ18O‐based reconstructed precipitation also corresponded to actual local drought and flood events from the documentary records. Reconstructed precipitation showed significant relationship with central tropical Pacific sea surface temperature, which indicated that El Niño–Southern Oscillation (ENSO) exerted influences on May–October precipitation in the lower reaches of the Yangtze River. In addition, the relationship between ENSO and precipitation weakened between 1920 and 1940, and low variance of ENSO from 1920 to 1940 may result in the damped ENSO's influences on precipitation in southeast China.