We analyzed the cold wave event dataset provided by the China Meteorological Administra-tion for the period 1951-2020 and the ERA5,to come up with the characteristics and trends of nationwide cold waves in China.We used the self-organizing map neural network method to investigate the primary modes affecting cold waves in China and the hybrid single-particle Lagrangian integrated trajectory model to track the trajectories of cold air associated with cold waves.The results indicated a significant decreasing trend in the cumulative number of nationwide cold wave occurrences in China from 1951 to 2020,with particularly decadal variations around the 1980s.Before that,the primary modes influencing cold waves included the Baikal low vortex type and the southeastward-extending polar vortex type cor-responding to the northwest path,the blocking high-polar vortex type corresponding to the northern path,the negative phase of the Arctic oscillation(AO)corresponding to a western path,and the positive phase of the North Atlantic oscillation corresponding to an eastern path.After the 1980s,the cumulative num-ber of cold wave occurrences rapidly decreased,and the invasion locations shifted eastern.The main modes became the blocking high-polar vortex type corresponding to the northwestern path,the Arctic high and blocking high linkage type corresponding to the northern path,the negative phase of the AO cor-responding to a western path,and the western polar vortex type corresponding to an eastern path.In this period,the invasion location of cold air associated with the northwestern path shifted eastward and its proportion decreased.The proportion of cold air associated with the eastern path increased.The newly emerged mode corresponding to the Arctic high and blocking high linkage featured a northern path,with a shorter invasion distance.Further research indicated that the Arctic high and blocking high linkage mode might have had an impact on winter weather and climate in China.In this mode,there was a block-ing high over the Ural Mountains and an Arctic high over the vicinity of Novaya Zemlya and Franz Josef Land,with both in-phase.The high-pressure ridge extended northeast to southwest,resulting in a north-ward shift,increased intensity and expanded influence range of the Siberian High,making it more prone to generate broad-ranging and significantly cooling cold waves along northern or eastern routes.The cooling range covered several regions including Northwest China,North China,and South China,with temperature drops reaching 8-10℃.
维普
万方数据
