资源环境科技发展态势分析平台

Spring Arctic Oscillation (AO) has been revealed to exert a great impact on the Northern Hemispheric climate; however, its seasonal prediction skill has been limited so far. In this paper, we find that the dominant mode of the winter 500-hPa geopotential height anomalies over the mid-latitude Eurasia has a close connection with the succeeding spring AO. The analysis on the physical processes indicates that the troposphere-stratosphere interaction plays an important role in the connection between the two. This predominant atmospheric mode in the mid-latitude Eurasia during winter can change the vertical wave activity and lead to an anomalous stratospheric polar vortex. Thereafter, the signal of the anomalous stratospheric polar vortex propagates downward to troposphere in the subsequent spring, consequently inducing the anomalous AO pattern in the troposphere. The results in this study imply that this previous winter leading atmospheric mode over the mid-latitude Eurasia may supply a potential source for a spring AO's prediction.