铜陵市近50年气温变化的小波分析

Wavelet Analysis on the Temperature Changes over the Late 50 Years in Tongling

[目的]研究铜陵市气温变化规律。[方法]利用连续小波变换分析气温变化时间序列的多时间尺度变化及突变特征，对铜陵市1960～2009年的气温资料进行了探讨。[结果]铜陵市气温的年际及年代际时间尺度在时域中分布不均匀，具有明显的局部化特征；近50年来铜陵市的气温大致经历了一个由偏冷转向偏暖的过程，转折点位于1995年前后；其气温变化具有多层次的时间尺度结构，阶段性特征明显，年平均气温、年最低平均气温及年最高平均气温三者间的变化特点在长周期上具有相似性，在短周期变化上不尽相同。[结论]连续小波变换能将气温时间序列的频率特征在时间域上展现出来，清晰地给出各种时间尺度的强弱、分布情况及气温冷暖变化趋势和突变点，从而找出气温变化的主要周期.

[ Objective] The researeh aimed to study the rule of the temperature changes in Tongling City. [ Method] By using the continuous wavelet transform which have proved changes in multi - time scale and jump characteristics of temperature time series to analyze the annual temperature time series of Tongling during 1960 -2009. [ Results] The temperature distribution about interannual and interdecadal time scales of Tongling City is uneven in the time domain,with significant localization features ; the past 50 years the temperature of Tongling City has gone through a process of being eool turning into warmer, the turning point was around 1995 ; the temperature changes with the time scale of multi - level structure, stage characteristics significantly, the long cycle of the annual average temperature, annual mean minimum temperature and the highest annual mean tmnperature change was similar, but for a short cycle, it is difterent. [ Conclusion] Continuous wavelet transform can show the characteristics of the temperature time series of the frequency domain in time, clearly shows the strength of various time scales, the distribution, and the trends and mutation of warm and cold temperature, so that people can identify the main periods of temperature changes.