Cold Waves in East China and Their Response to Two Types of Arctic Amplification

Cold waves occur frequently in East China, with their cold air source in the Arctic. Changes in the Arctic are often linked with Arctic amplification. The circulation anomaly associated with Arctic amplification is often represented by Arctic Oscillation (AO). In recent years, storms have frequently invaded the central Arctic region, resulting in dramatic changes in Arctic environment. In this paper, based on correlation studies, composite analysis, and case studies, the remote effects of the old and storm-induced Arctic amplification are compared, especially with regard to their impact on cold waves in East China. The results show that the AO can shed light on the interannual variation of cold events intermittently, although it cannot explain the increasing trend of cold waves in the southern part of East China. However, this long-term trend correlates well with storm activity. Cyclones are becoming more active in the western Arctic and anticyclones are intensifying in the eastern Arctic. In this scenario, the storm-induced warm advection could enhance the ridge over northeast Eurasia, the Siberian High expands southeastward, and cold air accumulates in northeast Asia, which cools the northern part of East China directly. The circulation around the Siberian High leads to a northeast wind in the southern part of East China, which plays a vital role in snowstorms. This study could improve our understanding of the global effects of Arctic changes and could enhance the prediction skill of cold waves.