This study reveals a marked enhancement in the relationship between the variations in location of the winter East Asian Polar Front Jet (EAPJ) and the surface air temperature (SAT) in Eurasia since the mid-1990s. Before the mid-1990s, an evident wave train related to the meridional location of the EAPJ exhibited an anticyclonic anomaly over northern Europe and a cyclonic anomaly in northwestern Asia. With an equatorward shift of the EAPJ after the mid-1990s, the wave train experiences a notable adjustment that is conducive to East Asian cooling, displaying an anticyclonic anomaly around the Kara-Laptev Seas and a cyclonic anomaly near northeastern Asia. Arctic warming anomalies and sea ice loss contributed significantly to these decadal changes. Simulation experiments forced by observed Arctic sea-ice variability further confirm this result. Since the mid-1990s, Arctic sea ice loss (or Arctic warming anomaly) has contributed to a reduction in westerly winds in high latitudes by modulating the meridional temperature gradient. The deaccelerated winds intensify the Arctic cold air propagating to the south, enhancing the atmospheric baroclinicity and the westerly flow in the upper level at the south side of the EAPJ, favoring the southward shift of the EAPJ. With the equatorward shift of the EAPJ, the corresponding SAT anomalies in East Asia are more salient.

这项研究揭示了自 1990 年代中期以来，冬季东亚极地锋流 (EAPJ) 位置变化与欧亚大陆表面气温 (SAT) 之间的关系显着增强。在 1990 年代中期之前，与 EAPJ 经向位置相关的明显波列在北欧上空出现反气旋异常，在亚洲西北部出现气旋异常。随着 1990 年代中期之后 EAPJ 向赤道移动，波列经历了有利于东亚降温的显着调整，在卡拉-拉普捷夫海周围显示出反气旋异常，在亚洲东北部附近显示出气旋异常。北极变暖异常和海冰流失对这些年代际变化做出了重大贡献。观测到的北极海冰变化迫使模拟实验进一步证实了这一结果。自 1990 年代中期以来，北极海冰流失（或北极变暖异常）通过调节经向温度梯度导致高纬度地区西风减弱。减速的风加强了北极冷空气向南传播，增强了EAPJ南侧上层的大气斜压性和西风气流，有利于EAPJ南移。随着 EAPJ 向赤道移动，相应的东亚 SAT 异常更加突出。增强了东太平洋联合体南侧上层大气斜压性和西风气流，有利于东太平洋联合体南移。随着 EAPJ 向赤道移动，相应的东亚 SAT 异常更加突出。增强了东太平洋联合体南侧上层大气斜压性和西风气流，有利于东太平洋联合体南移。随着 EAPJ 向赤道移动，相应的东亚 SAT 异常更加突出。