Heterodynes dominate precipitation isotopes in the East Asian monsoon region, reflecting interaction of multiple climate factors
Heterodynes dominate precipitation isotopes in the East Asian monsoon region, reflecting interaction of multiple climate factors
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东亚季风区降水同位素以外差为主，反映了多种气候因素的相互作用
DOI：
10.1016/j.epsl.2016.09.044
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发表时间：
2016
影响因子：
5.3
通讯作者：
Liu, Zhengyu
中科院分区：
文献类型：
--
作者：
Thomas, Elizabeth K.;Clemens, Steven C.;Sun, Youbin;Prell, Warren L.;Huang, Yongsong;Gao, Li;Loomis, Shannon;Chen, Guangshan;Liu, Zhengyu
在过去的十年里，东亚季风的历史一直被解释的背景下，一个非常好的，高分辨率的复合记录洞穴氧同位素（δ 18 Ocave）从长江流域。该记录的特点是独特的光谱响应，方差主要集中在岁差带内，而在偏心率和偏心率带处缺乏方差。在这里，我们研究了所有现有的>250 kyr-long的陆地水同位素记录在亚洲的光谱特征，包括一个新的水同位素记录使用叶蜡氢同位素比率从中国黄土高原。不同轨道尺度的亚洲水同位素记录在光谱特征上存在很大差异。我们证明，这些差异的结果，纬度梯度的影响，冬季和夏季季风，这两个影响整个东亚的气候和水同位素。因此，水同位素记录并不能反映单一季节或单一循环系统的降水。相反，东亚的水同位素记录反映了海洋和大陆水分来源的复杂相互作用，在多个地球轨道周期运行。这些非线性的相互作用反映在水的同位素光谱的外差的存在。虽然复杂，我们提出，水同位素记录，当与快速发展的同位素启用模型模拟配对时，将有可能阐明导致东亚季节性降水变化和水分来源变化的机制。
For the past decade, East Asian monsoon history has been interpreted in the context of an exceptionally well-dated, high-resolution composite record of speleothem oxygen isotopes (δ18Ocave) from the Yangtze River Valley. This record is characterized by a unique spectral response, with variance concentrated predominantly within the precession band and an enigmatic lack of variance at the eccentricity and obliquity bands. Here we examine the spectral characteristics of all existing >250-kyr-long terrestrial water isotope records in Asia, including a new water isotope record using leaf wax hydrogen isotope ratios from the Chinese Loess Plateau. There exist profound differences in spectral characteristics among all orbital-scale Asian water isotope records. We demonstrate that these differences result from latitudinal gradients in the influence of the winter and summer monsoons, both of which impact climate and water isotopes throughout East Asia. Water isotope records therefore do not reflect precipitation during a single season or from a single circulation system. Rather, water isotope records in East Asia reflect the complex interplay of oceanic and continental moisture sources, operating at multiple Earth-orbital periods. These non-linear interactions are reflected in water isotope spectra by the presence of heterodynes. Although complex, we submit that water isotope records, when paired with rapidly developing isotope-enabled model simulations, will have the potential to elucidate mechanisms causing seasonal precipitation variability and moisture source variability in East Asia.