基于复杂度分析冰芯和石笋代用资料时间序列的研究

运用动态非线性时间序列分析方法——Lemper-Ziv复杂度，分别计算了古里雅冰芯资料和北 京石花洞石笋资料的复杂度，探讨了复杂度的物理内涵及其在气候变化研究中的意义；小波 多尺度分解分析表明，复杂度序列具有明显的特征周期，存在780年、380年、160年和105年 的准周期.进一步研究发现，当取不同的窗口长度时，复杂度序列的特征基本相同；并且复 杂度序列的突变和气候突变在时间尺度上有着较好的对应关系.揭示了近千年来，在380年时 间尺度上的准周期振荡，其振幅一直是在减弱的，而且其固有周期频率逐渐减小.1900年复 杂度开始持续下降，1920年之后变化很小，类似于中国6世纪中期及12世纪中期的变暖期， 因此造成20世纪气候变暖的原因还有待于深入研究.关键词：Lemper-Ziv复杂度小波变换气候自然变率

Investigation on the time series of ice core and stalagmite based on the analysis of complexity

The complexity series of the Guliya (Tibetan plateau) ice core and Shihua cave (Beijing) stalagmite proxy records were respectively calculated in this paper, using a dynamical nonlinear analysis method for time series-Lemper-Ziv complexityalgorithm; and the physical implication of Lemper-Ziv complexity and its meaning in the study of climate change were also discussed. The wavelet analysis resul ts show that there exist distinctive quasi-periods of 780_, 380_, 160_, and 105_ year in the complexity series. Further investigations indicate that when differ ent window lengths are selected, the characters of the complexity series for a g iven time series are basically the same, and there exists the coherency between the jumps of the complexity series and the climatic jumps on various timescales . This paper presents, for the first time so far as we know, the oscillation on 380_year timescale in the recent millennium, with amplitude decaying and intri nsic period reducing. The complexity of the time series has gradually reduced si nce 1900. For the complexity of the stalagmite data,there has been the quasi-equ al-amplitude oscillation after 1920, which is similar to the circumstances of th e warming epochs over China in the middle of the sixth century and the middle o f the twelfth century. Consequently, the reason for the warming in the twentiet h century remains to be necessary to study.