【摘要】 在介绍了功率谱的概念及其计算方法的基础上 ,用功率谱的间接计算方法计算了农牧交错带内科尔沁沙地 8个气象观测点从 196 1— 2 0 0 0年降水量和温度的功率谱 .结果表明 :在步长为年的尺度下 ,4 0a的数据序列长度还不足以反映降水和温度的周期性规律 .在步长为旬的尺度下 ,降水量的变化总体上有较明显的 8～ 10a ,4 .4～ 4 .7a的周期性规律 ,其中尤以 9a ,4 .4a的周期最为显著 ,并且存在 2 .3a ,2 .5a ,6～ 7a的次明显周期 ;温度的变化总体上有较明显的 9a ,4 .4a ,3a和 2 .2a的周期规律 ,尤以 9a ,4 .4a的周期最为显著 .降水以及温度变化的周期性变化规律对进一步理解科尔沁沙地的生态环境演化具有重要的借鉴意义 .更多还原

【Abstract】 Power spectral or functional spectral analysis is a useful tool in studying the periodicity in many fields including the climatic data analysis. This paper runs back over the development and applications of the analysis of power spectral,introduces the concept and the means of computing of power spectral. The characteristic of precipitation and temperature changes within periods of ten days for 40 a from 1961—2000 at eight observation stations in Horqin sandy land were studied. By means of power spectral analysis, the periodic oscillations of temperature and rainfall in that region are studied quantitatively. The results of power spectral analysis of precipitation and temperature show that precipitation and temperature have no marked periodicities between years by computing the precipitation and the average temperature of 40 a,and the reason may be that the scales of yearly precipitation and temperature are too large and the sequence of 40 a is too short to find the notable periodicity. Therefore, the data of periods of ten days for the 40 a is studied according to four seasons. The results show that the periodicities of season precipitation are 8～10 a, 4.4～ 4.72 a and 2 a,especially 9 a and 4.4 a,and the periodicities of season temperature are 8～ 10 a, 4.4～ 4.7 a,3 a and 2.2 a,especially 9 a and 4.4 a.更多还原