On the evolution of Atlantic Meridional Overturning Circulation Fingerprint and implications for decadal predictability in the North Atlantic
On the evolution of Atlantic Meridional Overturning Circulation Fingerprint and implications for decadal predictability in the North Atlantic
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DOI：
10.1002/2015gl064596
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发表时间：
2015-07
影响因子：
5.2
通讯作者：
Jinting Zhang;Rong‐Hua Zhang
中科院分区：
文献类型：
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作者：
Jinting Zhang;Rong‐Hua Zhang
以前曾提出，与北大西洋深水层变化有关的大西洋经向翻转环流（AMOC）异常以34°N以北的平流速度向南传播。在这项研究中，使用地球物理流体动力学实验室耦合模式版本2.1（GFDL CM2.1），我们表明，这种缓慢的向南传播的AMOC异常的演变和增强的十年可预测性的AMOC指纹的主导模式的上层海洋热含量（UOHC）在北大西洋的extratrophic是至关重要的。北方高纬度地区的正AMOC异常导致副极地/墨西哥湾流区大西洋纬向热输送（MHT）异常的辐合/辐散，从而导致副极地环流（SPG）的变暖和墨西哥湾流区的变冷。最近的年代际预测研究成功地预测了SPG在20世纪90年代中期观测到的暖移。我们的结果为SPG UOHC年代际预报能力的增强提供了物理机制。
It has been suggested previously that the Atlantic Meridional Overturning Circulation (AMOC) anomaly associated with changes in the North Atlantic Deep Water formation propagates southward with an advection speed north of 34°N. In this study, using Geophysical Fluid Dynamics Laboratory Coupled Model version 2.1 (GFDL CM2.1), we show that this slow southward propagation of the AMOC anomaly is crucial for the evolution and the enhanced decadal predictability of the AMOC fingerprint—the leading mode of upper ocean heat content (UOHC) in the extratropical North Atlantic. A positive AMOC anomaly in northern high latitudes leads to a convergence/divergence of the Atlantic meridional heat transport (MHT) anomaly in the subpolar/Gulf Stream region, thus warming in the subpolar gyre (SPG) and cooling in the Gulf Stream region after several years. Recent decadal prediction studies successfully predicted the observed warm shift in the SPG in the mid‐1990s. Our results here provide the physical mechanism for the enhanced decadal prediction skills in the SPG UOHC.