关键词: 气候突变, 突变点, 子波变换, 子波方差, 层次结构

Abstract: In climatology, the cool/warm duration is defined as timeduration which the mean temperature is lower/higher. The cool/warm duration is a relative concept. In this paper, the wavelet transform is applied to surface air temperature (SAT) time series analyses for the Northern/Southern Hemisphere (NH/SH) during the last one hundred years. The cool/warm duration in different time scales are revealed. They constitute the hierarchical structure of SAT variations. On the basis of the hierarchical structure, the trend of future climate change is predicted. The results are as following: 1. SAT variations obviously appear features of climate jump. For Jones climate time series: In large time scale, the cool/warm duration last about 77 years in NH and 90 years in SH. The climate jump happened at 1923 in NH and 1939 in SH. In small time scale, the cool/warm duration last about 14 years in NH and 5.6 years in SH.2. According to the results of Jones climate time series, the trend of future climate change in NH will be: (1) The large warm duration is from 1923 to 2001. A large cool duration will begin at 2001;(2) The small cool duration is from 1991 to 2001, so the global warming caused by the strong increment of greenhouse effect will be stopped.

Key words: climate jump, wavelet transform, wavelet variance, hierarchical structure