北半球大气环流主模态时空分析

The Influence of Polar Vortex Area and Polar Vortex Intensity of Asian Area on Northern Hemisphere Climate in Winter

利用1948~2015年的NCEP/NCAR资料全球月平均再分析资料作经验正交分解(EOF),获得北极涛动指数(AOI)和北极偶极子指数(DAI)并对EOF分析后的时间序列进行回归分析。我们主要总结极地涡旋的四个方面,包括极地涡旋指数(极涡面积指数和极涡强度指数),其变化特征,以及对中国冬季气候的影响和极地涡旋影响因子。极地涡旋主要具有年际和年代际变化特征。此外,在年际时间尺度上,极地涡流区域在中国的温度和降水之间呈负相关,在年代际时间尺度上,极地涡流面积和中国温度呈现负相关。

Based on the monthly mean reanalysis data of NCEP / NCAR data from 1948 to 2015, through the Empirical Orthogonal Function (EOF), the AO index and DA index were obtained and the time series after EOF analysis were analyzed. We mainly summarize four aspects of the polar vortex, concluding the polar vortex index (PVA and PVI), its variation characteristics, its impact on the winter climate in China and the polar vortex impact factors. Polar vortex mainly has interannual and interdecadal variation characteristics. Besides, in interannual timescale, the polar vortex area demonstrates a negative correlation between temperature and precipitation in China, and in interdecadal timescale, polar vortex area and the temperature in China show a negative correlation.