摘要
本文利用1951—1984年500hPa月平均高空和月总降水资料,着重分析了500hPa距平场对长江中下游夏季降水的影响及其相关关系。针对长江中下游夏季降水这一预报对象,计算了500hPa距平场的信息区,指出在大尺度距平场的演变过程中,不同时间和不同地点距平场的量值对长江中下游这一特定顶报区域降水的影响是不同的。並且指出长江中下游地区冬季降水主要是受欧业型环流的影响,而夏季降水则主要是由于东亚—西太平洋型环流所形成。另外通过对实际距乎场和信息近似距平场的分析表明,信息区的变化在一定程度上反映了实际距平场的大尺度变化特点。
In this paper, the effect of the monthly mean geopotential height departure at 500hPa on the precipitation in June-August in the middle and lower reaches of Chang.Tiang River and their relation are analysed by using the monthly height fields at 500hPa and the precipitation data during 1951-1984. We calculated the information area of mean height departure at 500hPa in view of forcasting precipitation in the middle and lower ranches of ChangJiang Piver. It is pointed out that the effect of mean height departure fields of the different period and area on the preeipitation in this area is diffrcnt. We also showed that the precipitation in this area is affected by EU (Eurasia) pattern circulation in Wir-ter and by EA-WP(East Asia-West Paci fic)pattenn circulation in summer The analysed results still show that the changes of height departure fields in the info r-mat ion area can represent the characteristic of the large scale changes of the true height departure fields to a certain degree.
出处
《气象科学》
CSCD
北大核心
1990年第2期139-146,共8页
Journal of the Meteorological Sciences
