对1996年江淮梅雨的剖析

１９９６年江淮梅雨梅期长，梅雨量大，梅雨期暴雨频繁，属于长江中，下游流域性的洪涝 年。作者通过对西太平洋副热带高压，西风急流，中高纬阻塞形势，超长波及长波的增衰演变等的研究，分析了１９９６年梅雨期的划定，并通过对历史上４０年长江中，下游梅雨总量Ｍ值的非整数功率谱的分析指出：１９９６年出现流域性的大涝年是符合周期演变规律的。

An Analysis on Jianghuai Meiyu in 1996

In 1996 the period of the Jianghuai meiyu was longer,its precipitation was more and the heavy rain during the meiyu period also happened frequently.The situation is a flooding year in the middle and lower reaches of the Yangtze River.The West Pacific subtropical high,westerly jet,the blocking patterns of high and middle latitude,and the evolution of superlong wave and long wave were analysed.The subdivision of the meiyu period in 1996 was given.The non integer power spectrum of the total meiyu rainfall M in the middle and lower reaches of the Yangtze River in 40 years was studied,where M is the flood and drought index.It is indicated that the regional heavy flood year in 1996 is coincident with the evolution of the drought/flood periods.