酒泉市肃州区近55a的气候变化特征、突变与周期分析

利用1951-2005年酒泉市肃州区气象观测站平均气温和降水量资料,运用多年趋势线、5a滑动趋势线、Mann-Kendall突变检验、滑动t检验和小波分析等方法对肃州区气候变化的主要特征、突变特点和周期特征进行分析.结果表明:近55a来,肃州区年平均气温呈明显上升趋势,年降水量呈微弱减少趋势.年平均气温和年平均降水量均有明显的突变,前者突变年份在1992年,后者突变年份较多,以1995年最显著.Morlel小波及其功率谱分析表明,年平均气温和年平均降水量的变化周期具有多尺度、多层次和多分辨的特性结构.其中,年平均气温存在21a和7.14 a(P≤0.16)的优势周期,年降水量存在21a,10.87a,9.09a和6.41a(P≤0.1)的显著周期,且中长期优势周期一致,中短周期不同.

Characteristics and analysis of abrupt and cyclic climate changes in Suzhou District, Jiuquan City in recent 55 years

Based on the observed data of the mean annual temperature and precipitation from Suzhou district weather station from 1951-2005 in Jiuquan City, the main features of climate change, abrupt changes and changing periods were analyzed with a multi-year trend line, variation curve of 5a running mean, moving t-test technique, Mann-Kendall abrupt change test and wavelet analysis methods. The results indicate that a trend of the mean annually increasing but the mean annual precipitation decreased slightly in recent 55 years in Suzhou district and that the mean annual temperature and precipitation jumped in 1992 and in 1995, respectively. And then the Morlet wavelet and its power spectrum methods were used to analyze the periods of the mean annual temperature and precipitation. The results show that there are characteristics of multiple time scales, multiple layers and multiple resolutions in the time series of climate change and that there are temperature fluctuation periods of the 21 a and 7.14 a, precipitation fluctuation periods of 21 a,10.87 a, 9.09 a and 6.41 a. The long-moderate term fluctuation periods are consistent, different from the short-moderate term ones.