Greenhouse Gas and Ice Volume Drive Pleistocene Indian Summer Monsoon Precipitation Isotope Variability
Greenhouse Gas and Ice Volume Drive Pleistocene Indian Summer Monsoon Precipitation Isotope Variability
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温室气体和冰量驱动更新世印度夏季风降水同位素变率
DOI：
10.1029/2020gl092249
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发表时间：
2021-02
影响因子：
5.2
通讯作者：
S. McGrath;S. Clemens;Yongsong Huang;Masanobu Yamamoto
中科院分区：
文献类型：
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作者：
S. McGrath;S. Clemens;Yongsong Huang;Masanobu Yamamoto
轨道尺度的印度夏季风变率通常被解释为对北方半球夏季日照的直接响应。在这里，我们提出了一个连续的（0-640 kyr）轨道尺度的降水同位素（δDprecip）记录使用叶蜡δD从核心季风区的印度。δDprecip记录与温室气体最大值和所有轨道带的冰体积最小值在数量上是一致的，并且δDprecip最小值与温室气体最大值和冰体积最小值同相。δDprecip记录也与现有的两个轨道尺度的印度洞穴沉积物δ 18 O记录一致且同相，表明独立代理之间的一致区域响应。这些发现排除了印度降水同位素记录的解释作为一个直接的反应，北方夏季日照。相反，它们主要反映了与温室气体和冰量变化相关的水分来源和传输路径的变化。印度和东亚季风系统的轨道尺度降水同位素响应是不耦合的，并由不同的强迫驱动。
Orbital‐scale Indian Summer Monsoon variability is often interpreted as a direct response to northern hemisphere summer insolation. Here we present a continuous (0–640 kyr) orbital scale precipitation isotope (δDprecip) record using leaf wax δD from the core monsoon zone of India. The δDprecip record is quantitatively coherent with, and δDprecip minima in phase with, greenhouses gas maxima, and ice volume minima across all orbital bands. The δDprecip record is also coherent and in phase with the two existing orbital‐scale Indian speleothem δ18O records, demonstrating a consistent regional response among independent proxies. These findings preclude interpretation of Indian precipitation isotope records as a direct response to northern hemisphere summer insolation. Rather, they dominantly reflect changes in moisture source and transport paths associated with changes in greenhouse gases and ice volume. The orbital‐scale precipitation isotope responses of the Indian and East Asian monsoon systems are uncoupled and are driven by different forcings.