【摘要】 苏联粮食产量有准2年和4年振荡周期,它与准2年赤道平流层位相风有较好的对应关系,吹西风往往歉收;吹东风则经常丰收.并与南方涛动有4年左右同相振荡关系,涛动由高指数变化为低指数时,粮食大多为歉收;反之多为丰收.4—6月份500hPa环流形势,西欧有阻高建立且稳定,并在欧洲盛行“N”型环流形势时,则有利于粮食丰收;反之则歉收.更多还原

【Abstract】 The grain yield in the Soviet Union has oscillatory period of quasibiennial and quasi-quadrennial years. They have good relations with the change of the equatorial stratosphere phase wind and of the south oscillation indices respectively. The yield increased under the east wind and decreased under the west wind frequently. And the yield descended when the south oscillation indices dropped down or ascended when the indices arose up. In Europe during April to June a stable blocking high is maintained and if the circulation pattern takes the shape of "N", there will be an abundant harvest.更多还原