长沙气温的长期变化趋势及R/S分析

Temperature Variation Trend and R/S Analysis in Changsha

运用三阶幂函数和R/S分析法,对1951年以来长沙1月、7月和年平均的气温进行了分析.研究结果表明:①长沙气温总体呈上升趋势,增暖幅度与全国平均增暖幅度持平.20世纪90年代以前偏冷,20世纪90年代开始变暖,近10年变暖加剧.②长沙1月气温呈上升趋势,而7月气温呈下降趋势,1月气温变化对年平均气温变化的贡献大于7月.③R/S分析的结果得出,1月H值略小于0 5,说明冬季气温呈波动性变化;而7月和年平均H值达0 81,存在明显的Hurst现象,气温变化趋势具有持续性,7月气温将延续下降趋势,年平均气温将延续上升趋势.

Variation trends of January,July and annual mean temperature are calculated by means of cube function and R/S analysis since 1951.The results show that:①The temperature of Changsha has increasing warming trend and is in accord with China.During recent 10 years,the temperature has a obvious increase. ②The January temperature of Changsha has ascending trend,and the July temperature of Changsha has descending trend. ③The secular trend and R/S analysis show that H index of January temperature is nearly 0.5 and it shows January temperature has undulation.But H indexes of July and annual mean temperature reach 0.81.There are obvious Hurst effect,showing a persistence in secular variation trend of temperature.The secular trend of July temperature of Changsha will persist descending trend,and the annual mean temperature of Changsha will persist ascending trend.