Oxygen Isotopic Signatures of Major Climate Modes and Implications for Detectability in Speleothems
Oxygen Isotopic Signatures of Major Climate Modes and Implications for Detectability in Speleothems
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DOI：
10.1029/2020gl089515
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发表时间：
2020-12
影响因子：
5.2
通讯作者：
M. Midhun;S. Stevenson;J. Cole
中科院分区：
文献类型：
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作者：
M. Midhun;S. Stevenson;J. Cole
世界各地的自然和社会系统受到厄尔尼诺/南方涛动（ENSO），太平洋十年涛动（PDO）和大西洋多年涛动（AMO）等气候模式的影响，因此必须了解它们对气候变化的敏感性。古气候研究扩展了观测气候基线，洞穴沉积物记录（δ 18 O2）是一个常见的数据来源。然而，δ 18 O2和气候模态之间的关系是不确定的;气候模式提供了一种方法来测试这些关系的强度和稳定性。在这里，我们使用同位素启用的社区地球系统模型的最后千年Enclamation结合前向代理模型来描绘全球范围内的“假石笋”（δ 18 OH 3）记录中模态变化的全球表达。模拟的δ 18 O2在空间上与模态特征相关。然而，模态方差的实质性变化仅适度影响个体δ 18 Ohm方差。δ 18 Ospel记录网络，特别是跨越太平洋的网络，显着提高了ENSO方差的可重建性。
Natural and social systems worldwide are impacted by climate modes such as the El Niño/Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO) and Atlantic Multidecadal Oscillation (AMO), making it imperative to understand their sensitivity to climate change. Paleoclimate studies extend the observational climate baseline, and speleothem records (δ18Ospel) are a common data source. However, relationships between δ18Ospel and climate modes are uncertain; climate models provide a way to test the strength and stability of these relationships. Here, we use the isotope‐enabled Community Earth System Model's Last Millennium Ensemble combined with a forward proxy model to delineate the global expression of modal variability in “pseudo‐stalagmite” (δ18Ospel) records worldwide. The modeled δ18Ospel spatially correlates with modal signatures. However, substantial changes in modal variance only modestly affect individual δ18Ospel variance. A network of δ18Ospel records, particularly one that straddles the Pacific, significantly improves the reconstructability of ENSO variance.