Millennial Variability in an Idealized Ocean Model: Predicting the AMOC Regime Shifts
Millennial Variability in an Idealized Ocean Model: Predicting the AMOC Regime Shifts
复制标题
理想化海洋模型中的千禧年变异性：预测 AMOC 制度转变
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
A. Fedorov
中科院分区：
文献类型：
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作者：
F. Sévellec;A. Fedorov
摘要北大西洋末次冰期古记录的一个显著特征是明显的千年变化，通常被称为Dansgaard-Oeschger事件。据认为，这些事件与大西洋纬向翻转环流和热量输送的变化有关。在这里，作者基于海洋环流的霍华德-马尔库斯环表示制定了一个新的低阶模型，能够真实地再现千年变化及其混乱动态。它表明，即使在这种混乱的模式中的状态的纬向翻转环流的变化是可预测的。因此，作者定义了两个预测指数，给出了准确的预测时间的循环应该保持在打开阶段，然后留在随后的关闭阶段。这些指数主要取决于海洋分层，并描述了系统中小扰动的线性增长。因此，监测海洋状态的特定指数可以帮助预测…
AbstractA salient feature of paleorecords of the last glacial interval in the North Atlantic is pronounced millennial variability, commonly known as Dansgaard–Oeschger events. It is believed that these events are related to variations in the Atlantic meridional overturning circulation and heat transport. Here, the authors formulate a new low-order model, based on the Howard–Malkus loop representation of ocean circulation, capable of reproducing millennial variability and its chaotic dynamics realistically. It is shown that even in this chaotic model changes in the state of the meridional overturning circulation are predictable. Accordingly, the authors define two predictive indices which give accurate predictions for the time the circulation should remain in the on phase and then stay in the subsequent off phase. These indices depend mainly on ocean stratification and describe the linear growth of small perturbations in the system. Thus, monitoring particular indices of the ocean state could help predict ...