Annular Variability and Eddy–Zonal Flow Interactions in a Simplified Atmospheric GCM. Part I: Characterization of High- and Low-Frequency Behavior
Annular Variability and Eddy–Zonal Flow Interactions in a Simplified Atmospheric GCM. Part I: Characterization of High- and Low-Frequency Behavior
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简化大气 GCM 中的环形变率和涡流-纬向流相互作用第一部分：高频和低频行为的表征。
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
J. Haigh
中科院分区：
文献类型：
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作者：
S. Sparrow;M. Blackburn;J. Haigh
摘要 使用简化的牛顿强迫全球环流模型进行了实验，以研究如何通过检查环空变率的两种主要模式的组合波动来表征对流层急流的变率。使用垂直积分动量预算在主导模式的相空间中分析这种可变性的涡流强迫。环形变化和涡流强迫的性质取决于时间尺度。在低频下，纬向流和斜压涡流处于准平衡状态，异常向极地传播。涡流主要是为了强化异常状态，并通过线性阻尼紧密平衡，留下缓慢的演化作为残余。在高频下，气流强烈演变，异常现象在对流层急流的极地一侧开始并向赤道传播。涡流被证明强烈推动了这种演变：涡流位置和振幅反映了过去的斜压性，而......
Abstract Experiments have been performed using a simplified, Newtonian forced, global circulation model to investigate how variability of the tropospheric jet can be characterized by examining the combined fluctuations of the two leading modes of annular variability. Eddy forcing of this variability is analyzed in the phase space of the leading modes using the vertically integrated momentum budget. The nature of the annular variability and eddy forcing depends on the time scale. At low frequencies the zonal flow and baroclinic eddies are in quasi equilibrium and anomalies propagate poleward. The eddies are shown primarily to reinforce the anomalous state and are closely balanced by the linear damping, leaving slow evolution as a residual. At high frequencies the flow is strongly evolving and anomalies are initiated on the poleward side of the tropospheric jet and propagate equatorward. The eddies are shown to drive this evolution strongly: eddy location and amplitude reflect the past baroclinicity, while ...