The El Niño Southern Oscillation (ENSO) is one of the most prominent modes of coupled variability with sizable impacts on global climate and weather patterns, which makes the ability to predict the occurrence and development of ENSO events of fundamental importance. In order to achieve accurate and timely predictions, a well-established strategy is to understand and monitor known ENSO precursors. In this paper, we focus on North Pacific Oscillation (NPO)-related precursors, namely the trade wind charging and the Northern Pacific meridional mode (TWC/NPMM). In particular, we assess whether the TWC/NPMM mode and its relationship with ENSO is reconstructed across the CMIP6 protocol-driven ensemble High Resolution Model Intercomparison Project, which was developed to systematically test the impact of increased horizontal resolution. Here, we see that the TWC/NPMM is a consistent precursor of ENSO across the ensemble, notwithstanding some spatial variations in the reconstruction. Furthermore, previous analyses on observationally-based data show that the TWC/NPMM-ENSO relationship is robust, albeit not stationary, and its variations can influence the characteristic variability of ENSO itself. In particular, during those years when the TWC/NPMM-ENSO coupling is weak, ENSO oscillates regularly with constant periodicity; whereas, when the coupling is strong, ENSO shows a more stochastic behavior. A selected subset of better-performing HighResMIP models are able to reproduce the non-stationarity of the TWC/NPMM-ENSO coupling and to recreate how these variations are reflected in the characteristics of ENSO variability, similar to what was recorded in the observational analysis. In parallel with these analyses, we also assess their sensitivity to horizontal resolution and find that there is no consistent impact of resolution on the results described above.

厄尔尼诺南方涛动 (ENSO) 是最突出的耦合变率模式之一，对全球气候和天气模式有相当大的影响，这使得预测 ENSO 事件发生和发展的能力至关重要。为了实现准确和及时的预测，一个成熟的策略是了解和监测已知的 ENSO 前体。在本文中，我们关注与北太平洋涛动（NPO）相关的前兆，即信风充电和北太平洋经向模式（TWC/NPMM）。特别是，我们评估了 TWC/NPMM 模式及其与 ENSO 的关系是否在 CMIP6 协议驱动的集合高分辨率模型比对项目中得到重建，该项目旨在系统地测试水平分辨率增加的影响。这里，我们看到 TWC/NPMM 是整个集合中 ENSO 的一致前兆，尽管重建中存在一些空间变化。此外，先前对基于观测数据的分析表明，TWC/NPMM-ENSO 关系是稳健的，尽管不是静止的，其变化会影响 ENSO 本身的特征变异性。特别是在TWC/NPMM-ENSO耦合较弱的年份，ENSO以恒定的周期性规律地振荡；然而，当耦合强时，ENSO 表现出更随机的行为。选定的性能更好的 HighResMIP 模型子集能够重现 TWC/NPMM-ENSO 耦合的非平稳性，并重新创建这些变化如何反映在 ENSO 变异性的特征中，类似于观测分析中记录的内容。