Dynamics of Synoptic Eddy and Low-Frequency Flow Interaction. Part I: A Linear Closure
Dynamics of Synoptic Eddy and Low-Frequency Flow Interaction. Part I: A Linear Closure
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DOI：
10.1175/jas3715.1
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发表时间：
2006-07
影响因子：
3.1
通讯作者：
F. Jin;Lin-lin Pan;M. Watanabe
中科院分区：
文献类型：
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作者：
F. Jin;Lin-lin Pan;M. Watanabe
摘要几十年来，天气涡旋和低频气流（SELF）之间的相互作用在大气环流低频变率的动力学中起着重要的作用。在这三个部分的研究中，提出了一个线性框架与一个随机的基本流捕捉气候学平均流量和天气学措施的涡旋流。基于这个线性框架，导出了一组由异常时均流产生的系综平均涡动强迫的线性动力学方程。通过假定这种动力学决定的涡强迫距平近似代表天气学涡强迫的时间平均距平，并利用准平衡近似，得到了双向SELF反馈的解析非局部动力学闭合。这种线性闭合，直接关系到时间平均异常的天气涡旋强迫的异常时间平均流量，成为一个新的线性动力系统的内部部分，为一个新的线性动力系统。
Abstract The interaction between synoptic eddy and low-frequency flow (SELF) has been recognized for decades to play an important role in the dynamics of the low-frequency variability of the atmospheric circulation. In this three-part study a linear framework with a stochastic basic flow capturing both the climatological mean flow and climatological measures of the synoptic eddy flow is proposed. Based on this linear framework, a set of linear dynamic equations is derived for the ensemble-mean eddy forcing that is generated by anomalous time-mean flows. By assuming that such dynamically determined eddy-forcing anomalies approximately represent the time-mean anomalies of the synoptic eddy forcing and by using a quasi-equilibrium approximation, an analytical nonlocal dynamical closure is obtained for the two-way SELF feedback. This linear closure, directly relating time-mean anomalies of the synoptic eddy forcing to the anomalous time–mean flow, becomes an internal part of a new linear dynamic system for an...