Ocean Eddy Dynamics in a Coupled Ocean-Atmosphere Model*
Ocean Eddy Dynamics in a Coupled Ocean-Atmosphere Model*
复制标题
海洋-大气耦合模型中的海洋涡动力学*
DOI：
10.1175/jpo3041.1
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发表时间：
2007
影响因子：
3.5
通讯作者：
J. McWilliams
中科院分区：
文献类型：
--
作者：
P. Berloff;W. Dewar;S. Kravtsov;J. McWilliams
摘要分析了中尺度海洋涡旋在大雷诺数下的准地转海气耦合模式中的作用。模式动力学的特点是年代际变化，涉及海洋对大气南北一致变化的非线性调整。采用适用于非平稳外强迫的动力分解方法对海洋涡动效应进行诊断。涡旋的主要作用是加强了分离副极地和副热带涡旋的大洋东向急流，并减弱了涡旋。这种增流效应是由于涡流强迫的波动驱动的非线性整流所致。这是一个非局地过程，涉及西边界流和东向急流上游部分的流动不稳定所产生的涡旋。涡旋被平均气流平流到东面，在那里它们向后散射成向东急流的整流增强。回旋减弱效应，这是由于……
Abstract The role of mesoscale oceanic eddies is analyzed in a quasigeostrophic coupled ocean–atmosphere model operating at a large Reynolds number. The model dynamics are characterized by decadal variability that involves nonlinear adjustment of the ocean to coherent north–south shifts of the atmosphere. The oceanic eddy effects are diagnosed by the dynamical decomposition method adapted for nonstationary external forcing. The main effects of the eddies are an enhancement of the oceanic eastward jet separating the subpolar and subtropical gyres and a weakening of the gyres. The flow-enhancing effect is due to nonlinear rectification driven by fluctuations of the eddy forcing. This is a nonlocal process involving generation of the eddies by the flow instabilities in the western boundary current and the upstream part of the eastward jet. The eddies are advected by the mean current to the east, where they backscatter into the rectified enhancement of the eastward jet. The gyre-weakening effect, which is due...