The North Atlantic Tripole sea surface temperature anomaly (NAT SSTA) is critical for predicting climate in Eurasia. Predictions for summer climate anomalies currently assume the NAT SSTA phase persists from boreal winter through summer. When NAT phase switches, predictions become unreliable. However, the NAT phase sustained/reversal mechanism from boreal winter to spring remains unclear. This study demonstrates that the evolution of the NAT phase could be driven by the North Atlantic Oscillation (NAO). When NAO phase persists (switches) during preceding boreal winter, the NAO-driven wind anomalies favor maintenance (transition) of NAT phase by causing sea surface heat flux anomalies. Meanwhile, NAT SSTA causes eddy-mean flow interaction by increasing atmospheric baroclinity, thereby generating positive feedback on the former NAO phase. The NAO phase change is leading 1–3 months for the NAT phase. These findings deepen our understanding of the interaction between NAO and NAT and provide implications for seasonal prediction in Eurasia.

北大西洋三极子海面温度异常 （NAT SSTA） 对于预测欧亚大陆的气候至关重要。目前对夏季气候异常的预测假设 NAT SSTA 阶段从北方冬季持续到夏季。当 NAT 阶段切换时，预测变得不可靠。然而，从北方冬季到春季的 NAT 阶段持续/逆转机制仍不清楚。这项研究表明，NAT 阶段的演变可能是由北大西洋涛动 （NAO） 驱动的。当 NAO 相在前一个北方冬季持续存在（转换）时，NAO 驱动的风异常通过引起海面热通量异常来促进 NAT 相的维持（过渡）。同时，NAT SSTA 通过增加大气气压度引起涡流-平均流相互作用，从而对前 NAO 相产生正反馈。NAO 阶段的变化导致 NAT 阶段需要 1-3 个月。这些发现加深了我们对 NAO 和 NAT 之间相互作用的理解，并为欧亚大陆的季节预测提供了启示。