Characteristics and spatial distribution of strong warming events in the central Arctic (2000–2019)

Arctic amplification in the context of global warming has received considerable attention, and mechanisms such as ice–albedo feedback and extratropical cyclone activity have been proposed to explain such abnormal warming. Since 2000, several short-term episodes of significant temperature rise have been observed in the Arctic; however, long-duration warming events in the central Arctic are less common and lack comprehensive research. Previous studies identified that amplified Rossby waves could connect Arctic warming with extreme weather events in mid-latitude regions, and thus the recent increase in the frequency of mid-latitude extreme weather is also a subject of intensive research. With consideration of temperature anomalies, this study defined a continuous warming process as a warming event and selected strong warming events based on duration. Analysis of National Centers for Environmental Prediction Reanalysis-2 surface air temperature data found that nine strong warming events occurred during 2000–2019, which could be categorized into three types based on the area of warming. This study also investigated the relation between strong warming events and sea ice concentration reduction, sudden stratospheric warming, and extratropical cyclone activities. After full consideration and comparison, we believe that strong warming events in the central Arctic are induced primarily by continuous transport of warm air from mid-latitude ocean areas.