The first EOF mode (EOF1) of summer storm track activity over the North Atlantic is characterized by a dipole structure, with negative storm track anomalies over the south coast of Greenland extending northeast across Iceland to the Norwegian Sea and positive anomalies over coastal western Europe. This study shows that a significant interdecadal change in the North Atlantic storm track during boreal summer occurred around the mid-2000s. After the mid-2000s, the EOF1 occurs more frequently at its positive phase, which is associated with an interdecadal increase in the geopotential height anomalies around Greenland. On the intra-seasonal timescale, the anticyclonic anomalies around Greenland are crucial for the occurrence of positive EOF1 events via triggering eastward propagating Rossby waves. Therefore, the interdecadal increase in the geopotential height anomalies around Greenland tends to facilitate the occurrence of the positive EOF1 event and is therefore a key driver of the interdecadal change in the summer storm track activity over the North Atlantic. Further analysis indicates that the development of anticyclonic anomalies around Greenland is maintained by the self-interaction among the low- and high-frequency transients themselves. Moreover, the anomalous synoptic eddy activities associated with the change in storm tracks can in turn amplify and maintain the Rossby waves triggered by the anticyclonic anomalies around Greenland in the synoptic-scale eddy feedback process.

北大西洋夏季风暴活动的第一个EOF模式（EOF1）具有偶极子结构，格陵兰岛南海岸的负风暴路径异常向东北延伸，横跨冰岛到挪威海，西欧沿海地区为正异常。这项研究表明，在北半球夏季风暴期间，北大西洋风暴轨迹发生了明显的年代际变化，发生在2000年代中期左右。在2000年代中期之后，EOF1在其正相位发生的频率更高，这与格陵兰岛周围的地势高度异常年代际增加有关。在季节内时间尺度上，格陵兰岛附近的反气旋异常通过触发向东传播的Rossby波，对于EOF1正事件的发生至关重要。因此，格陵兰岛周围的地势高度距平年代际增加趋向于促进EOF1正事件的发生，因此是北大西洋夏季风暴轨迹活动年代际变化的关键驱动力。进一步的分析表明，格陵兰周围反气旋异常的发展是由低频和高频瞬变自身之间的自相互作用维持的。此外，与风暴径变化有关的天气异常涡旋活动又可以放大和保持由天气尺度涡旋反馈过程引起的格陵兰岛反气旋异常触发的罗斯比波。