全球变化背景下安徽近55 a气温时空变化特征

基于安徽省80个气象站的月值气温观测数据,采用线性倾向率、Mann-Kendall突变检验、小波分析和R/S分析等数理统计方法,研究多时间尺度下的气温变化特征。结果表明:1)近55 a安徽省气候呈现明显的暖化趋势,年均气温及春、秋、冬季气温均呈明显上升趋势,其中春季升温幅度最显著,年平均气温在20世纪90年代波动幅度最大;2)年平均气温在1996年发生了突变,与突变前相比,突变后的平均气温增加了0.82℃,年平均气温发生了较大的变化,增暖趋势显著;3)近55 a安徽省年平均气温的变化主要存在5~8 a和10~15 a周期振荡,由小波方差图可以确定年平均气温存在6 a和11 a的主周期;4)安徽省年及四季平均气温的Hurst指数都大于0.5,表明存在显著的Hurst现象,即在不同时间段,该地区的气温时间序列大体上延续历史变化趋势,说明近55 a来安徽省的气温变化存在趋势性成分。春季和冬季Hurst值最高,表明与其他季节相比,春季和冬季的增温持续性最强,是年平均增温的主要贡献者。

Spatio-temporal Change of Surface Air Temperature in Anhui Province in the Context of Global Warming from 1960 to 2014

Based on monthly temperature data from 80 stations in Anhui Province, the long term daily temperature were analyzed during 1960-2014. The characteristics of temperature change were analyzed by using the linear regression, Mann-Kendall (M-K) test, rescaled range (R/S) analysis, wavelet transforms and other mathematic statistic methods. Important results were obtained as follows: 1) There was a significant climate warming trend in Anhui Province during recent 55 years (0.19 ℃/10 a, P = 0.005). Significant increase trends were also found in the spring, autumn and winter temperature. The spring average temperature had the largest and most obvious trend of increase (0.29 ℃/10 a, P < 0.001). The trend of average summer temperature was not obvious (0.01 ℃/10 a, P = 0.069). The annual average temperature showed big fluctuation in 1990s. 2) An abrupt change of the temperature wavelike rising tendency in 1996 was detected by M-K test. The temperature increased by 0.82 ℃ after the change point. The annual average temperature had a great change and the warming trend was very significant. There were significant change points of average spring temperature, autumn temperature and winter temperature in 1999, 1998 and 1986, respectively. And there were no significant change point of average summer temperature. 3) The oscillating periods of average temperature in the past 55 years was complex, being a nested structure of multiple time scales. The wavelet analysis showed that there were two periods of 5-8 years and 10-15 years for the oscillation of temperature in Anhui Province. After the analysis of wavelet variance plots, it was found that main cycles of annual mean temperature were 6 years and 11 years. 4) Hurst indexes of annual mean temperature and seasonal temperature were all greater than 0.5. It indicated that there will be obvious Hurst phenomenon in the future (Hurst index was 0.891), which means that there is tendency of the climate change in Anhui Province during recent 55 years. The Hurst index was higher in spring and winter, and the warming rate in winter was higher than that in summer and autumn. It could be deduced that the increase of temperature in spring and winter was the main contributor to the increase of annual average temperature. The result of this paper can be used as a reference for further analysis of climate change as well as the impacts of climate change and the responses of water resources to climate change in Anhui Province.