Oceanic Pathways of an Active Pacific Meridional Overturning Circulation (PMOC)
Oceanic Pathways of an Active Pacific Meridional Overturning Circulation (PMOC)
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DOI：
10.1029/2020gl091935
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发表时间：
2021-05
影响因子：
5.2
通讯作者：
M. Thomas;A. Fedorov;N. Burls;W. Liu
中科院分区：
文献类型：
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作者：
M. Thomas;A. Fedorov;N. Burls;W. Liu
与现代气候相反，北太平洋深水形成和太平洋纬向翻转环流（PMOC）可能在过去的气候条件下一直活跃，特别是在上新世时期（大约300 - 500万年前）。在这里，我们使用一个强大的PMOC细胞的气候模式模拟研究北太平洋深水从俯冲到上涌的途径，揭示了拉格朗日粒子轨迹。我们发现，类似于今天的大西洋经向翻转环流（AMOC），大多数俯冲的北太平洋深水在南大洋上升。然而，大约15%的上升流出现在热带印度洋-太平洋，这是PMOC与AMOC区别开来的一个关键特征。与印度洋的连接相对较快，约为250年。与热带太平洋的连接是缓慢的（约1800年），因为水首先到达亚热带南太平洋，然后逐渐上升通过温跃层。
In contrast to the modern‐day climate, North Pacific deep water formation and a Pacific meridional overturning circulation (PMOC) may have been active during past climate conditions, in particular during the Pliocene epoch (some 3–5 million years ago). Here, we use a climate model simulation with a robust PMOC cell to investigate the pathways of the North Pacific deep water from subduction to upwelling, as revealed by Lagrangian particle trajectories. We find that similar to the present‐day Atlantic Meridional Overturning Circulation (AMOC), most subducted North Pacific deep water upwells in the Southern Ocean. However, roughly 15% upwells in the tropical Indo‐Pacific Oceans instead—a key feature distinguishing the PMOC from the AMOC. The connection to the Indian Ocean is relatively fast, at about 250 years. The connection to the tropical Pacific is slower (∼800 years) as water first travels to the subtropical South Pacific then gradually upwells through the thermocline.