南京地区地面平均气温的变化

Variations of Mean Surface Air Temperature in Nanjing Area

基于 40年南京地区 1 0 0 0 h Pa上逐月和全年的平均气温资料 ,首先分析了逐月及年平均气温的长期趋势变化 ,发现 40年来平均气温有明显增温趋势 ,但逐月平均气温变化趋势则与年平均气温不同 ,在初夏及深秋到冬季有明显增温 ,在 3月和 7月有降温 ;然后利用距平累加和信噪比法探讨了气温的突变 ,发现逐月平均气温在 1 972年 4月和 1 976年 6月存在明显的突变特征 ,而全年平均气温则在 1 972年存在一次弱突变 ;最后利用功率谱分析了逐月及年平均气温的周期变化 ,发现年平均气温存在 2 .2年的短周期振荡和 1 0年的中周期振荡。

Based on the mean monthly and annual temperature data of Nanjing area at 1 000 hPa for the last 40 years, the study of long term climatic variation trend of surface air temperature is conducted, which shows that the variation trend of mean annual temperature is rising, but the monthly trend is different from the annual one. The obvious rising in monthly trend happens in early summer and from late autumn to winter, and descending in May and July. Then the methods of accumulate anomalies and Signal to Noise are used to analyse the climatic jump. The results show that there was obvious jump of mean monthly temperature in April 1972 and June 1976, but the mean annual temperature only experienced the week jump in 1972. Finally, the method of power spectrum is used to analyse the variation of period, and it is showed that the mean annual temperature has short periodic oscillation in 2.2 years and medium periodic oscillation in 10 years.