Previous studies have suggested that boreal spring Northern Atlantic Oscillations (NAOs) exert a pronounced influence on the following East Asian summer monsoon (EASM) variability. This study reveals that the relationship between the spring NAO and the following EASM varies with the 11-year solar cycle. The analysis of the time–lag relationship between the NAO in May and the following summer rainfall indicates that during the low solar activity (LS) summers, a more robust relationship is established, with below-normal rainfall anomalies in South China and the Sunda Islands in relation to a positive NAO. In addition, the May NAO-related atmospheric circulation anomalies during boreal summer over East and Southeast Asia may well explain the distinct rainfall difference. The possible mechanism for this solar modulation is attributed to the changes in structure of the spring NAO and associated tripole SST anomalies in the North Atlantic. Specifically, in the LS phase, the North Atlantic tripole SST anomalies associated with the May NAO can strongly develop and persist into the early summer. These SST anomalies tend to induce a remarkable subpolar wave train across the northern Eurasian continent and an enhanced East Asian jet in the summer. Our results indicate that, for the summer climate prediction over East and Southeast Asia, both the spring NAO and the 11-year solar cycle should be considered.

中文翻译：

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北方春季北大西洋涛动与东亚和东南亚夏季气候关系的太阳周期调制

先前的研究表明，北方春季北大西洋涛动 (NAO) 对随后的东亚夏季风 (EASM) 变化产生显着影响。这项研究揭示了春季 NAO 与随后的 EASM 之间的关系随 11 年的太阳周期而变化。5 月 NAO 与随后夏季降雨量的时滞关系分析表明，在低太阳活动 (LS) 夏季，建立了更稳健的关系，华南和巽他群岛的降雨量低于正常水平与积极的 NAO 相关。此外，东亚和东南亚北半球夏季5月与NAO相关的大气环流异常可能很好地解释了明显的降雨差异。这种太阳调制的可能机制归因于春季 NAO 结构的变化和北大西洋相关的三极海温异常。具体而言，在 LS 阶段，与 5 月 NAO 相关的北大西洋三极海温异常可以强烈发展并持续到初夏。这些海温异常往往会在整个欧亚大陆北部引发显着的次极波列，并在夏季引发增强的东亚急流。我们的结果表明，对于东亚和东南亚的夏季气候预测，应同时考虑春季 NAO 和 11 年太阳周期。与 5 月 NAO 相关的北大西洋三极海温异常可以强烈发展并持续到初夏。这些海温异常往往会在欧亚大陆北部引起显着的次极波列，并在夏季引起东亚急流增强。我们的结果表明，对于东亚和东南亚的夏季气候预测，应同时考虑春季 NAO 和 11 年太阳周期。与 5 月 NAO 相关的北大西洋三极海温异常可以强烈发展并持续到初夏。这些海温异常往往会在欧亚大陆北部引起显着的次极波列，并在夏季引起东亚急流增强。我们的结果表明，对于东亚和东南亚的夏季气候预测，应同时考虑春季 NAO 和 11 年太阳周期。