关键词: 变温, 降水, 谱分析, 西太平洋副热带高压

Abstract:

The influence of Australian cold air activities on precipitation of middle and lower reaches of the Changjiang River within main flood season is studied initially by using statistical methods of spectrum.Moreover,the West Pacific Subtropical High affects grievously the above influence.The data root in Australian 700 hPa analytical temperature and precipitation of middle and lower reaches of the Changjiang River.Conclusions are as follows:During summer season of China a 77 days period of the temperature alteration of Australian day to day and rainfall of the middle-lower reaches of the Changjiang River occurs in wet year,this means that there is a remote correlation of 77 days between them and they have inphase surging in the 77day period.Besides,Australian cold air activities affect rainfall of the middlelower reaches of Yangtze River after 73 days.The affecting processes are:when Australian cold air activity is stronger,WPSH moves northward and the middlelower reaches of Yangtze River is sunny and controlled by WPSH;when Australian cold air activity weakens,WPSH moves southward and the middlelower reaches of Yangtze River locate on the edge of WPSH with rainy days.To some extent the abovementioned conclusions provide forecasting foundation during main flood season of the middle and lower reaches of Changjiang River.

Key words: temperature alteration, precipitation, spectrum, The West Pacific Subtropical High