基于西安市1960-2007年的降水数据和太阳黑子相对数,采用一元线性回归、Mann—Kendall检验等方法,对西安降雨量进行分析,然后采用小波分析方法研究了西安夏、秋两季降水量与太阳黑子之间的关系。结果表明:夏、秋两季降水量约占西安全年降水量的80%;西安夏季降水量呈上升趋势,秋季降水量则呈下降趋势;降水量的变化与太阳黑子数多少密切相关,在太阳黑子出现极值年及2a左右,降水量也出现极值;西安夏季降水量有10a左右的周期,秋季降水量有9a左右周期;太阳黑子在9a时间尺度上与降水量有很强的相关性,且夏季降水量与太阳黑子相差1—2a的正相关,秋季降水量则与太阳黑子提前2a左右的负相关关系。
Based on the data of rainfall in Xi'an and the number of sunspots during the period from 1960 to 2007, a time series of precipitation was analyzed using the simple linear regression and Mann-Kendall test as well as other statistical methods. The wavelet analysis was used to study the relationship between the number of sunspots and rainfall in summer and autumn. The results showed that the proportion of rainfall in summer and autumn was a- bout 80% of annual precipitation in Xi'an. Rainfall in Xi'an in summer was in an increase trend, but that in au- tumn was in a decrease trend. Precipitation in Xi'an was closely related to the number of sunspots, and the maxi- mum value of precipitation occurred when the maximum number of sunspots occurred or around 2 years. There was a 10-year periodic fluctuation of rainfall in summer, and also a 9-year periodic fluctuation of rainfall in autumn. There was a high correlation between the number of sunspots and precipitation at 9-year scale, a positive correlation between rainfall in summer and the number of sunspots with one or two-year difference, but a negative one between rainfall in autumn and the number of sunspots with one or two-year ahead of time.