Atmospheric Circulation Anomalies Linked to the Extreme Cold Event over Northeast Asia in February 2025 and the Underlying Mechanism

In early February 2025, Northeast Asia (NEA) experienced the most severe extreme cold event reported in recent decades. However, the underlying atmospheric mechanisms remain insufficiently understood. This study employs the circulation projection method to extract historical variations in atmospheric circulation anomalies and quantifies their contribution to the extreme cold event. The results indicate that circulation anomalies accounted for approximately 86% of the minimum temperature anomalies during this period. The dominant circulation pattern resembles the Polar–Eurasia teleconnection pattern, characterized by an anomalous southward intrusion of cold air from high latitudes into NEA, leading to the rapid and intense cooling. Furthermore, the potential precursors influencing the circulation anomalies are explored. Specifically, the Arctic sea ice loss in the preceding October and anomalously dry soil conditions over eastern Europe in December are found to modulate large-scale atmospheric circulation through anomalous diabatic heating, thereby creating favorable dynamical conditions for the extreme cold event in NEA.