The modes of Pacific decadal-scale variability (PDV), traditionally defined as statistical patterns of variance, reflect to first order the ocean's integration (i.e., reddening) of atmospheric forcing that arises from both a shift and a change in strength of the climatological (time-mean) atmospheric circulation. While these patterns concisely describe PDV, they do not distinguish among the key dynamical processes driving the evolution of PDV anomalies, including atmospheric and ocean teleconnections and coupled feedbacks with similar spatial structures that operate on different timescales. In this review, we synthesize past analysis using an empirical dynamical model constructed from monthly ocean surface anomalies drawn from several reanalysis products, showing that the PDV modes of variance result from two fundamental low-frequency dynamical eigenmodes: the North Pacific–central Pacific (NP-CP) and Kuroshio–Oyashio Extension (KOE) modes. Both eigenmodes highlight how two-way tropical–extratropical teleconnection dynamics are the primary mechanisms energizing and synchronizing the basin-scale footprint of PDV. While the NP-CP mode captures interannual- to decadal-scale variability, the KOE mode is linked to the basin-scale expression of PDV on decadal to multidecadal timescales, including contributions from the South Pacific.

中文翻译：

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太平洋年代际尺度变率的模式和机制


太平洋年代际变率 （PDV） 的模态，传统上被定义为方差统计模式，它首先反映了海洋对大气强迫的整合（即变红），这种强迫是由气候（时间平均）大气环流强度的变化引起的。虽然这些模式简明扼要地描述了 PDV，但它们并没有区分驱动 PDV 异常演变的关键动力学过程，包括大气和海洋遥相关以及在不同时间尺度上运作的具有相似空间结构的耦合反馈。在这篇综述中，我们使用从几个再分析产品中提取的每月海洋表面异常构建的经验动力学模型综合了过去的分析，表明 PDV 方差模式由两个基本的低频动态特征模态产生：北太平洋-中太平洋 （NP-CP） 和黑潮-大潮扩展 （KOE） 模式。两种特征模态都强调了双向热带-热带遥相关动力学如何成为激发和同步 PDV 流域尺度足迹的主要机制。NP-CP 模式捕获了年际到年代际尺度的变化，而 KOE 模式与 PDV 在年代际到多年代际时间尺度上的流域尺度表达有关，包括来自南太平洋的贡献。