湖南省近40年来伏旱期气温的时空变化特征分析

利用湖南省29个站近40年(1960-1999年)伏旱期(7-9月份)的气温资料,采用经验正交函数分解法(EOF)和旋转经验正交函数分解法(REOF)分析气温空间变化特征,用气候趋势系数、累积距平和连续功率谱等方法分析气温时间变化特征。结果表明,湖南省伏旱期气温的空间变化具有很好的主体一致性,而且依据空间异常类型可分为湘中区、湘北区、湘西南区、湘南区4个区;从时间演化特征来看,湘南区的江华站与其它3个区的代表性站点在气温变化上有较大差异,即在1989年出现了由冷到暖的突变,之后有比其它站点非常明显的上升趋势,而且有着准22 a的变化周期,与全球的增暖具有一致的趋势。

Spatial-temporal Characteristics of Air Temperature during Summer Drought in Hunan Province in Recent 40 Years

By using the air temperature data from 29 stations of Hunan Province during summer drought in the recent 40 years(1960-1999),the spatial change characteristic of air temperature is analyzed with the methods of EOF and REOF;Its temporal change characteristic is done with the methods of climatic tendency coefficient,cumulative anomaly and power spectrum analysis.The results show that:the spatial change of air temperature in summer drought had a good consistency in Hunan Province,the spatial abnormal area could be divided into four sections,including central Hunan,northern Hunan,southwestern Hunan and southern Hunan.As for the temporal change characteristic of air temperature,the representative station of Jianghua in southern Hunan differed sharply from other three representative stations,temperature in Jianghua had a significant break from cold to warm in 1989,and a very obvious increasing trend in next decennium,and the temperature changes had a 22-year periodic oscillation,which was consistent with the trend of global warming.