雅鲁藏布江中游河谷气温时序变化的小波分析

通过对雅鲁藏布江中游河谷地区拉萨、日喀则、江孜和泽当等4个气象站1957～2007年逐日气温资料进行等权平均取值，采用气候倾向率和小波分析法，研究了不同时间尺度下近51 a气温变化趋势及周期特征。结果表明：近50 a年平均气温倾向率为0.27℃/10 a，高于西藏地区平均值。气温变化以秋、冬季较显著，夏季气温增长最不明显。年与各季气温变化均存在15～20 a时间尺度上的周期性震荡，突变点在1987年左右，总体表现为1987年前气温偏低，1987年后处于偏高期。春、秋、冬季在1975年左右存在一个升温期，但夏季较明显的升温期却在20世纪80年代中期。
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WAVELET ANALYSIS OF ANNUAL TEMPERATURE VARIATION IN THEMIDDLE REACHES OF THE YARLUNG ZANGBO RIVER VALLEY,CHINA

his paper explored the temperature variation in the region of middle reaches of the Yarlung Zangbo river valley of Tibet in China in past 51 years.The observed meteorological data during 1957 to 2007,including average mean temperature in annual,seasonal and daily times series,had been used to study the characteristics of temperature change trend using the linear statistical method and wavelet analysis method.It was showed that the annual temperature presented a significant increasing trend and the change rate was 027℃/10 a in recent 51 a.It was more significant than the lower altitudes in other parts of Tibet.The warming trend was more obvious in autumn and winter than in summer.There were obvious periodic oscillation of 15~20 a for the seasonal and annual mean temperature variations.The abrupt climate change point was about in 1987,and the temperature belonged to the lower period before that time,and higher period after that time.There were an increasing trend in spring,autumn and winter in 1975,but this trend wasn’t appeared until summer in 1983.