Abstract: The purpose of the study is to investigate influences of stratospheric circulation anomalies on NCV. Using the NCEP/NCAR (daily and month mean) dataset over 1958?2010, the authors performed statistical and composite analyses on the characteristics and three dimensional structures of NCV for stratospheric northern-hemisphere annular mode anomalies. It shows that NCV has more frequent occurrences and longer duration during negative stratosphere NAM anomalies than that during positive NAM anomalies. Composite results show that NCV is stronger during negative stratospheric NAM anomalies than that during positive NAM anomalies. It is also found that during negative stratospheric NAM anomalies NCV is more closely related to downward, eastward and equatorward propagation of stratospheric anomalies, indicating that negative stratospheric NAM may enhance formation and development of NCV and lead to colder weather in Northeastern China. The results have important implications for medium range forecasting NCV in the winter season.

Key words: northern-hemisphere annular mode, northeast cold vortex, planetary waves, stratosphere-troposphere interaction, medium range forecasting

摘要： 为了研究平流层环流异常对东北冷涡的影响, 使用NCEP/NCAR(1958?2010年)再分析资料(日平均、月平均位势高度场及温度场), 对平流层NAM (northern hemisphere annular mode, 北半球环状模)异常期间东北冷涡的活动特征和三维空间结果进行了统计和合成分析。结果发现, 与平流层NAM正异常相比, 在平流层NAM负位相异常期间, 东北冷涡发生的频次更多和持续天数更长, 强度也更强。对平流层NAM不同位相异常期间的合成分析表明, 在平流层NAM负位相异常期间, 东北冷涡强度更强, 与平流层环流异常联系更紧密。同时平流层NAM负位相异常期间, 有强的行星波活动, 行星波的活动促进和加强了东北冷涡的发展。研究结果对使用平流层NAM异常预测冬季东北冷涡有重要意义。

关键词: 北半球环状模, 东北冷涡, 行星波动, 平流层?对流层相互作用, 中长期天气预报