摘要 : <正> Many authors examined the mean monthly circulation by means of harmonic analysis. Zhu analysed the mean monthly 500 mb contours at 60°N and 30°N. Guo et al. investigated the circulation in the Southern and Northern Hemisphere... 展开 <正> Many authors examined the mean monthly circulation by means of harmonic analysis. Zhu analysed the mean monthly 500 mb contours at 60°N and 30°N. Guo et al. investigated the circulation in the Southern and Northern Hemispheres and the monsoon over East Asia from the global normal sea-level pressure field, and confirmed the well-known role of Afro-Eurasia in the formation of monsoon over East Asia. 收起