气候代用资料动力学结构的区域与全球特征

From regional to global dynamics structure of the climatic proxy

介绍一种非线性时间序列分析方法——动力学相关因子指数Q(简称Q指数),是基于相空间重构技术的动力学指标,它能有效识别时间序列之间动力结构的异同性.利用该方法分析了几种典型代用资料的动力学结构,发现它们的演变特征基本相似,区域和全球范围的气候同步变化,区域气候受到全球气候系统制约.近2000年来的区域到全球气候系统有两个明显动力结构突变期:700—900a和1300—1700a,它们所对应的环境变化可能是中世纪暖期和现代小冰期事件.

Global change science is a new research domain nowadays, and one of the most important studies of which is the climate change,to which great attention is paid by all governments in world. It is mainly based on the climatic proxy that we can study the past climate change. Although many achievements have been obtained, majority of the results are limited to the external characteristics of the proxy due to lagged analysis methods. For example, we judge if the climate is flood/drought or cold/warm through linear trend of the time series, however, we do not know whether it is a natural variation or the result of external forces, the mechanism is not uncovered. Because complexity of the open global climate system, there are different characteristics among the climatic proxies from different region of the world, from which it is difficult to reveal the intrinsic general principles i.e. the globality. For the further study on the past climate change, especially to reveal the rulcs of the global climate change in past 2000a and predict future climate change, a new method making use of the dynamical lag correlation exponent （named Q index in the text）, a dynamics exponent based on the phase-space reconstruction, is introduced in this paper, which can effectively discern the similarities or differences between the dynamics of the two series. With Q index, we analyze the dynamics structure of some typical climatic proxies. The results show that the dynamics of climatic proxies are almost similar, and the regional climate keeps the same change with the global. In other words, regional climate is controlled by the global climate change. Besides, there are two dynamics jump periods （namely 700-900a and 1300-1700a） in past 2000a of the climate system, which may correspond to the periods of the medieval warm period and the little ice age, respectively.