Unlike prior researches focusing on interannual or interdecadal changes of the Northwest Pacific subtropical high (NWPSH), this paper emphasizes the interdecadal changes in the relationship between May-June and July-August NWPSH. The correlation coefficients between them are 0.66 (passing the 99.9% confidence level) and 0.12 during 1979–2002 and 2003–2023. Therefore, the May-June NWPSH has a strong connection with July-August East Asian precipitation during 1979–2002, but not during 2003–2023. The interdecadal variations in the relationship of NWPSH are due to interdecadal changes of ENSO. During 1979–2002, the eastern-type ENSO in prior winter, having longer durations, can influence May-June and July-August NWPSH and the North Indian Ocean. However, the central-type ENSO in prior winter only persists it's influence until May-June, and changes into a Pacific Dipole pattern in July-August during 2003–2023. Despite the North Indian Ocean continually warms during 2003–2023, the tropical Pacific Dipole offsets its impacts on the NWPSH.

中文翻译：

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5—6 月和 7—8 月 NWPSH 关系的年代际变化及其物理机制


与以往关注西北太平洋副热带高压 （NWPSH） 年际或年代际变化的研究不同，本文强调 5-6 月和 7-8 月西北太平洋副热带高压关系的年代际变化。它们之间的相关系数在 1979-2002 年和 2003-2023 年期间分别为 0.66（通过 99.9% 置信水平）和 0.12。因此，5 月至 6 月的 NWPSH 与 1979-2002 年 7 月至 8 月的东亚降水有很强的联系，但在 2003-2023 年期间则没有。NWPSH 关系的年代际变化是由于 ENSO 的年代际变化造成的。在 1979-2002 年期间，前一个冬季的东部型 ENSO 持续时间较长，可以影响 5 月至 6 月和 7 月至 8 月的 NWPSH 和北印度洋。然而，前一个冬季的中心型 ENSO 的影响仅持续到 5 月至 6 月，并在 2003 年至 2023 年的 7 月至 8 月转变为太平洋偶极子模式。尽管北印度洋在 2003 年至 2023 年期间持续变暖，但热带太平洋偶极子抵消了其对 NWPSH 的影响。