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Numerous studies have demonstrated that the North Pacific Meridional Mode (NPMM) plays an important role in determining El Niño‐Southern Oscillation (ENSO) events in the following winter season. However, little attention has been given to significant differences among its spatial patterns. Here we show that the NPMM exhibits a large diversity in spatial patterns, leading to distinct impacts on ENSO. Based on objective clustering analysis, two distinct spatial patterns of NPMM are detected. Cluster 1 (C1) NPMM exhibits a strong sea surface temperature dipole over the subtropical eastern Pacific and midlatitude central Pacific whereas Cluster 2 (C2) features a dipole over the subtropical eastern Pacific and equatorial cold tongue region. We find that the C1 NPMM is strongly linked to following ENSO events while the C2 NPMM has no statistically significant relation. This gives new implications for ENSO dynamics and predictions. Key Points: The North Pacific Meridional Mode (NPMM) has strong spatial diversity that can be separated into two groupsThese two types of the spring NPMM have distinct impacts on ENSO events in the following winterWe suggest an optimal pattern of the spring NPMM for ENSO prediction [ABSTRACT FROM AUTHOR]

Previous studies have shown that the Pacific Meridional Mode (PMM) has a crucial impact on the central Pacific El Niño–Southern Oscillation (ENSO). In this study, we redefined the PMM index used previously by focusing on the sea surface temperature in the subtropical northeastern Pacific (NEP), and found that the correlations between the PMM and ENSO are distinct on different timescales. We refer to this redefined index as PMM NEP. Results show that a positive PMM is weakly related to El Niño, while a negative PMM is more convincingly related to La Niña, specifically, the equatorial negative SSTAs possibly affecting negative PMM events. Moreover, the cause–effect relation between the PMM NEP and ENSO is much more significant on a decadal timescale than on an interannual timescale, and their interaction may be related to the equatorial zonal wind field. Our finding indicates that a La Niña-like decadal pattern is established through the combined actions of the PMM and ENSO, rather than an El Niño-like decadal pattern. • The PMM index defined in this study removes the signals of ENSO more effectively. • A positive PMM is weakly related to El Niño, while a negative PMM is more convincingly related to La Niña. • The relation between the PMM and ENSO is much more significant on a decadal timescale than on an interannual timescale. [ABSTRACT FROM AUTHOR]