赤道平流层准两年振荡与华北南部夏季降水

通过资料分析发现:夏季50hPa QBO的东、西风位相与华北南部降水及旱涝状况的关系存在显著的阶段性,并明显地受太阳活动11年周期的影响。分析表明,50年代以来,太阳活动11年周期双周内,平流层夏季50hPa QBO西风位相年华北南部降水偏多,东风位相年降水偏少;反之,在单周内东风位相年降水偏多,西风位相年降水偏少。分析还表明,平流层夏季50hPaQBO纬向风强度自身的演变也存在显著的跃变过程,在太阳活动11年周期单周内东风平均强度较双周显著增强。

Relationship between the Summer Precipitation in the South of North China

It is found that the relationship between the phase of 50 hPa QBO in summer season and the precipitation and drought/flood trend in the south of North China is featured with distictive stages, and is notably affected by the 11-year solar cycle. For the period of 1951-1989, in the even-numbered 11-year solar cycle the positive anomaly occurs in the west phase of the 50 hPa QBO and negative anomaly occurs in the east phase of the QBO, while in the odd-numbered 11-year solar cycle the positive anomaly occurs in the east phase of the 50hPa QBO and negative anomaly occurs in the west phase of QBO. The evolution of QBO intensity at 59 hPa is analyzed, which shows the marked sudden change processes, andin the odd-numbered 11-year solar cycle the intensity of east zonal wind is stronger than that in the even-numbered cycles.