Tree-ring δ18O in southwestern China linked to variations in regional cloud cover and tropical sea surface temperature
Tree-ring δ18O in southwestern China linked to variations in regional cloud cover and tropical sea surface temperature
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DOI：
10.1016/j.chemgeo.2011.10.001
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发表时间：
2012-01
期刊：
影响因子：
3.9
通讯作者：
Xiaohong Liu;W. An;K. Treydte;X. Shao;S. Leavitt;S. Hou;Tuo Chen;Weizheng Sun;D. Qin
中科院分区：
文献类型：
--
作者：
Xiaohong Liu;W. An;K. Treydte;X. Shao;S. Leavitt;S. Hou;Tuo Chen;Weizheng Sun;D. Qin
在本文中，我们提出了来自中国西南部温带湿润森林中生长的树木的晚材纤维素的第一个年度氧同位素（δ18O）记录（1902年至2004年）。树木年轮δ18O范围为12.8至18.6‰，平均值为15.2‰。晚材中的 δ18O 与 1951 年至 2004 年潮湿月份（8 月至 10 月）的总云量、相对湿度和降水量呈负相关，并且在较小程度上与 6 月的温度呈正相关。空间相关分析表明，树木年轮晚材δ18O与区域云量和秋季降水的变化有较强的相关性。树轮δ18O与印度夏季风（1948年至2004年）、西北太平洋季风（1948年至2004年）和东亚夏季风（1902年至2000年）的指数呈负相关，表明这些季风对区域气候有强烈影响。在上世纪全球变暖的背景下，我们发现不同时期的树木年轮δ18O与南方涛动指数之间存在很强的负相关性，表明厄尔尼诺南方涛动与区域气候之间存在复杂的关联，进而影响树木年轮δ18O。与全球海面温度（SST）的相关性表明，印度洋的气候条件可能在季风季节调节研究区域的云量和降水方面发挥主导作用。我们还发现西北太平洋树木年轮 δ18O 与海表温度之间存在显着相关性。我们的结果表明，热带海洋和类 ENSO 气候与研究区域的氧同位素来源和树木歧视之间存在密切联系。
In this paper, we present the first annual oxygen isotope (δ18O) record (1902 to 2004) from the latewood cellulose of trees growing in a temperate-moist forest in southwestern China. Tree-ring δ18O ranges from 12.8 to 18.6‰ and averages 15.2‰. δ18O in the latewood negatively correlates with total cloud cover, relative humidity, and precipitation during the moist months (August to October) from 1951 to 2004 and, to a lesser extent, positively correlates with the temperature in June. Spatial correlation analysis revealed that tree-ring latewood δ18O is more strongly related to variability in regional cloud cover and precipitation in autumn. Tree-ring δ18O negatively correlates with the indices of the Indian summer monsoon (1948 to 2004), the western North Pacific monsoon (1948 to 2004), and with the East Asian summer monsoon (1902 to 2000), suggesting that these monsoons strongly influence the regional climate. Under global warming of last century, we found a strong inverse correlation between tree-ring δ18O and the Southern Oscillation index in different periods, indicating a complex association between the El Niño-Southern Oscillation and the regional climate, which in turn affects tree-ring δ18O. Correlation with the global sea surface temperature (SST) indicates that climatic conditions in the Indian Ocean might play a dominant role in modulating cloud cover and precipitation over the study region during the monsoon seasons. We also found a significant correlation between tree-ring δ18O and SST over the western-north Pacific Ocean. Our results suggest strong links between tropical oceans and an ENSO-like climate with the oxygen-isotope sources and discrimination for trees in the study region.