ZHANG Zelu1,*, ZHAO Jinping 1 & BIAN Lingen2
1 College of Oceanic and Atmospheric Sciences, Ocean University of China, Qingdao 266100, China;
2 Chinese Academy of Meteorological Sciences, Beijing 100081, China
Abstract Arctic amplification has been paid much attention in the context of global warming. Studies have provided mechanisms, such as ice albedo-feedback, extratropical cyclone activity, to illustrate this abnormal phenomenon. Since 2000, it is not rare to observe that temperature rises significantly in the Arctic, whereas the long-duration warming events in the central Arctic happened not so often and lack full research. Previous studies also pointed out that amplified Rossby waves could connect Arctic warming with extreme weathers in midlatitude and thus Arctic warming could affect midlatitude profoundly. The frequency of extreme weather in midlatitude also rises a lot which calls for the research to study it. With anomaly temperature, this paper defined a continuous warming process as a warming event and select strong warming events based on the time duration. Our analysis based on NCEP reanalysis-2 surface air temperature data found that there exists 9 strong warming event totally in this century, which can be characterized by 3 types corresponding to different warming areas. This paper also discussed the relation between strong warming events obtained with 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 mainly induced by warm air from the midlatitude ocean entering into the central Arctic continuously.
Keywords Arctic Amplification, warming event, midlatitude, extreme weather, warm air